For a complete description of commands to configure and maintain Catalyst 5000 series switches, refer to the Catalyst 5000 Series Software Configuration Guide and the Catalyst 5000 Series Command Reference publications. For complete switch hardware configuration and maintenance procedures, refer to the Catalyst 5000 Series Installation Guide. For information on Catalyst 5000 series switching modules, refer to the Catalyst 5000 Series Module Installation Guide. These documents are available on the Cisco Connection Documentation, Enterprise Series CD, or in print.

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Document Contents

This document contains the following sections:

Only trained and qualified personnel should be allowed to install or replace this equipment.

What is the Catalyst 5000 Switch?

The Catalyst 5000 series switch provides high-density switched Ethernet and Fast Ethernet for both wiring closet and data center applications. The switch includes a single, integrated 1.2-Gbps switching backplane that supports switched Ethernet with repeater connections, Fast Ethernet with backbone connections, Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), Asynchronous Transfer Mode (ATM), and 4- and 16- Mbps Token Ring. The Catalyst 5000 provides switched connections to individual workstations, servers, LAN segments, backbones, or other Catalyst 5000 switches using shielded twisted-pair (STP), unshielded twisted-pair (UTP), and fiber-optic cable. Figure 1 is an example of a configuration using the Catalyst 5000 series switch.

Figure 1 Cascaded Catalyst 5000 Switches using Fast Ethernet and Token Ring Interfaces

Depending on the Catalyst 5000 series switch model that you are using, there are up to 11 interface slots available on the switch. Regardless of the Catalyst 5000 series switch, interface slot 1 supports a supervisor engine module, which provides Layer 2 switching, local and remote management, and dual Fast Ethernet interfaces. Slot 13 on the Catalyst 5500 switch is reserved for the ATM Switch Processor (ASP) module. The remaining slots are used for any combination of modules for additional Ethernet, Fast Ethernet, CDDI/FDDI, ATM, and Token Ring connections. Figure 2 shows the rear view of the Catalyst 5000 series switch, which provides access to the supervisor engine, all switching modules, power supplies, and fan assembly.

Figure 2 Switch Chassis Rear View of the 5-slot Catalyst 5000 Switch

What is the Token Ring Switch Module?

The Token Ring module, shown in Figure 3 has 16 shielded RJ-45 connectors for Token Ring connections. These ports allow full or half duplex connections to other switches, hubs, or end nodes.

Figure 3 Token Ring Module

The Catalyst 5000 series Token Ring module provides the following features:

16 Token Ring ports, individually programmable and capable of running in 4- or 16- Mbps, full- or half duplex, and behaving as either a concentrator or end station
Frame forwarding between ports and modules
Concentrator and bridge relay functions that enable switching between ports.
Switching features

Full bridge-mode support: source-route bridging (SRB), source-route switching, source-route transparent (SRT) bridging.
Store-and-forward frame-forwarding mode
4-Mbps, 16-Mbps, and automatic speed adaption
Dedicated Token Ring (DTR) support
Priority queues for multimedia traffic
Address and protocol filters
All-routes explorer (ARE) reduction
Spanning-Tree Protocol (STP) support: IBM, IEEE 802.1d, Cisco

Virtual LAN (VLAN) support

1024 VLANs per switch
63 emulated LANs per ATM link
VLAN Trunking Protocol, Version 2

Management Utilities and Support

Simple Network Management Protocol (SNMP)-based management
CiscoView graphical monitoring
TrafficDirector for Remote Monitoring (RMON)
Ability to monitor port traffic via Switch Port Analyzer (SPAN)
Ability to monitor soft error conditions occurring in your network and to receive notification of the stations that are exceeding user-defined error thresholds on a port (requires Token Ring software Release 3.3(1) or later)
Ability to issue a Remove Ring Station MAC frame to remove a station from a ring (requires Token Ring software Release 3.3(1) or later)

Note The Catalyst 5000 series Token Ring module requires supervisor engine module software, Release 3.1 or later. Soft error monitoring and remove adapter support requires Token Ring software Release 3.3(1) or later and supervisor engine module software Release 5.1(1) or later.

Bridging Modes

The Catalyst 5000 series Token Ring module applies the IEEE 802.5 annex K models of Concentrator Relay Functions (CRFs) and Bridge Relay Functions (BRFs). The Token Ring Concentrator Relay Function (TrCRF) and the Token Ring Bridge Relay Function (TrBRF) models support for the following bridging modes:

SRB
Source-route switching
Source-route transparent bridging (SRT)

For more information about bridging modes, please see the "Understanding Token Ring Switching" section. For more information on TrBRFs and TrCRFs, see the "Token Ring VLANs" section.

Token Ring Port Operation

Each of the 16 Token Ring ports on the Catalyst 5000 series Token Ring module can operate in one of the following modes:

Half-duplex concentrator port—Port is connected to a single station in half duplex (HDX) mode. In this case, the port behaves like an active medium access unit (MAU) port for classic Token Ring.
Half-duplex station emulation—Port is connected to a port on an MAU. In this case, the port behaves like a station connected to a classic Token Ring segment that contains multiple stations.
Full-duplex concentrator port—Port is connected to a single station in full duplex (FDX) mode.
Full-duplex station emulation—Port is connected to another Token Ring switch in FDX mode.

The mode of operation can be configured, or it can be automatically sensed when equipment is connected to the port. The media speed (4 or 16 Mbps) can also be configured or automatically sensed in all port modes.

Transmission Speed Adaption

The Catalyst 5000 series Token Ring module supports 4- and 16-Mbps Token Ring transmission speeds. You can configure ports on the Catalyst 5000 series Token Ring module to operate at one of these speeds or to automatically sense the speed of the ring to which it is connected. However, with Token Ring technology, a transmission speed cannot be changed without closing and reopening the port, therefore the following rules apply:

If the port is open and running at a transmission speed that is the same as the speed you specify when entering the set port speed command, no action is performed.
If the port is open and running at a speed different from a speed you specify when entering the set port speed command, the port will close and reopen at the new transmission speed.
If the port is closed, you can change the speed without any restrictions.

Note If the ports on the Token Ring module are configured to automatically sense the speed of the ring, the first port inserted on the ring will not set the speed, for it will be unable to detect the speed.

Note Closing and opening the port on an existing ring at a different transmission speed from which the ring is currently operating will cause the port to issue a beacon on that ring.

Dedicated Token Ring Support

The Catalyst 5000 series Token Ring module supports a new token passing standard called Dedicated Token Ring (DTR). DTR is the IEEE 802.5R standard that:

Enables a switch port to act as a concentrator port, which allows you to connect the port of the switch directly to an end station.
Transmits in Transmit Immediate (TXI) mode (also referred to as full duplex mode), increasing the aggregate bandwidth to 32 Mbps.

DTR is particularly useful for providing improved access to central resources, such as network servers, for servers can be directly attached to a switch.

Transmission Priority Queues

To address the needs of delay-sensitive data, such as multimedia data, each port on the Catalyst 5000 series Token Ring module has two data queues: high-priority and low-priority.

The queue for a frame is determined by the value of the priority field in the frame control (FC) byte of the frame. If the FC priority is above the user-defined priority level (the default is 3), the frame is put in the high-priority queue and is transmitted using the frame priority. If the FC priority is at or below the user-defined priority level, then the frame is sent to the low-priority queue.

Note The defaults for the priority queue maintain compatibility with current source-route bridges and provide a high-priority queue for Token Ring multimedia traffic (priorities 5 and 6).

For information on defining a priority level, see the "Setting the Frame Priority Levels" section.

Filtering

Many bridged networks today use filtering to reduce broadcast traffic, block protocols, and provide basic security. The Catalyst 5000 series Token Ring module provides filtering capabilities for the same purpose.

You can filter frames based on the following:

Media Access Control (MAC) address (source address [SA] or destination address [DA])
Protocol (Destination Service Access Point [DSAP]/Subnetwork Access Protocol [SNAP])

MAC address filters can be configured for only input ports. DSAP/SNAP filters can be configured for both input and output ports. You can configure up to 16 MAC address or DSAP/SNAP filters for each port on the Token Ring module.

To filter data based on MAC address, you specify an address and indicate whether you want to block or allow frames that contain the address as a source or destination address. To filter data based on protocol, specify either a DSAP or SNAP and specify whether to permit or deny frames with that protocol.

For information on configuring filters, see the "Configuring Filters" section.

ARE Reduction

For parallel SRB or SRT backbones, ARE reduction ensures that the number of ARE frames generated by the switch does not overwhelm the network.

The IEEE 802.1d SRT standard specifies two optional ways of reducing the ARE explosion. The Catalyst 5000 series Token Ring module discards any ARE frames that have already been on a ring that is attached to the switch.

This mechanism is configurable and ensures that only one ARE frame is received on each ring within each VLAN. The number of ARE frames is equal to the number of external parallel paths between the rings. If a port on the switch fails, or is disabled, the switch will no longer check for this ring number in the Routing Information Field (RIF). This bypass allows frames to travel on alternate paths.

By default, ARE reduction is enabled. For information on enabling and disabling ARE reduction, see the "Enabling and Disabling ARE Reduction" section.

Virtual LAN Support

With a VLAN, logical rings can be formed by defining port groups that have the same ring number. The IEEE standard calls such a Token Ring port group a TrCRF. Within the TrCRF, source-route switching is used for forwarding based on either MAC addresses or route descriptors (RDs). You can configure the entire VLAN to operate as a single ring (for example, a single TrCRF).

Multiple logical rings or TrCRFs can be interconnected via a single TrBRF. The TrBRF provides either the SRB or SRT switching mode. For source routing, the switch, or network of switches, appears as a single bridge between the logical rings. If SRB is used, duplicate MAC addresses can be defined on different logical rings.

For more information on Token Ring VLANs, see the "Token Ring VLANs" section. For information on configuring a VLAN, see the "Configuring VLANs" section.

STP Support

When creating a fault-tolerant internetwork, a loop-free path must exist between all nodes in a network. A spanning-tree algorithm is used to calculate the best loop-free path through a Catalyst 5000 series switched network. Spanning-tree packets are sent and received by switches in the network at regular intervals. The packets are not forwarded by the switches participating in the STP, but are instead used by the switches to identify the loop-free path. STPs perform this function for Catalyst 5000 series switches.

The Catalyst 5000 series switch uses the IEEE 802.1d or Cisco Spanning-Tree protocols on all TrCRFs. The IBM or IEEE Spanning-Tree protocol is used on all TrBRFs. For more information on the STPs running on TrCRFs and TrBRFs, see the "Configuring STP" section. The default configuration has all STPs enabled.

For more information on STPs, see the "Configuring STP" section.

Configuration and Management

With the Catalyst 5000 series Token Ring module, you can preform the following tasks:

Manage the Token Ring module using the command-line interface (CLI)
Manage the Token Ring module using an SNMP-based manager
Monitor the Token Ring module using an RMON agent or external monitoring device
Monitor the Token Ring module port traffic using SPAN
Monitor soft error conditions occurring in your network and receive notification of the stations that are exceeding user-defined error thresholds on a port
Issue a Remove Ring Station MAC frame to remove a station from a ring

SNMP-Based Management

The Catalyst 5000 series Token Ring module can be managed via an SNMP manager (such as CiscoView). The Token Ring module supports nine Management Information Bases (MIBs). Six of the MIBs are standard MIBs, which are defined by RFCs and are included with most SNMP management applications. Three of the MIBs are Cisco proprietary MIBs and can be obtained from CCO. See the "Cisco Connection Online" section for access to CCO information.

In addition to the standard MIBs supported the Catalyst 5000 series switch, the Token Ring module supports the following additional MIBs:

Token Ring Extensions to the Managed Objects for Bridges (RFC 1525)
IEEE 802.5 Token Ring MIB (RFC 1748)
RMON MIB/Token Ring Extensions (RFC 1513) partial support

The proprietary MIBs supported are:

Cisco Workgroup MIB (CISCO-STACK-MIB)
VLAN Trunk Protocol (VTP) pruning (CISCO-VTP-MIB)
Cisco VLAN Bridging (CISCO-VLAN-BRIDGING-MIB)

Most user configurable variables are supported in either the standard MIBs or private MIBs. Configuration settings, such as port attributes, and operational information, such as address tables, are fully accessible through SNMP. Certain other settings, such as passwords and console settings, cannot be viewed or modified via SNMP for security reasons.

CiscoView Support

CiscoView is a graphical user interface device management software application that provides dynamic status, statistics, and comprehensive configuration information for Cisco System's switched and internetworking products. CiscoView allows you to display configuration and performance information, and perform minor troubleshooting tasks.

RMON Support

RMON is an industry-standard method for providing network statistics monitoring using SNMP. It also collects fault, performance, and configuration statistics. RMON can monitor continuously, even when communication with the management station is not possible or efficient. It can then notify the management station when an exceptional condition occurs.

In typical SNMP management, the SNMP manager has to continuously poll the Catalyst 5000 series switch for fault, performance, and configuration information while waiting for the value to change. This causes increased traffic through the network. With RMON, you can have the switch monitor a particular statistic internally, and when the statistic reaches a threshold the Catalyst 5000 series switch will send a trap to the client. This monitoring method reduces traffic between the SNMP manager and the Catalyst 5000 series switch.

As an option, the Catalyst 5000 series Token Ring module provides RMON support statistics, history, alarms, and events. It also provides support for the following groups of the Token Ring extensions to the Remote Network Monitoring MIB (RFC 1513):

MAC-layer statistics group

A collection of MAC-layer statistics kept for each Token Ring interface, such as the total number of MAC packets received and the number of times the port entered a beaconing state.

Promiscuous statistics group

A collection of promiscuous statistics kept for non-MAC packets on each Token Ring interface, such as the total number of good non-MAC frames received that were directed to an LLC broadcast address.

Token Ring ring station control table

The Catalyst 5000 series Token Ring module supports the ringStationControlTable portion of the Token Ring Ring Station Group. This support allows a Catalyst 5000 series Token Ring module to gather segment information from each ring segment to which it is attached. This segment information includes Ring State, Beacon Sender, Beacon NAUN, and Active Monitor MAC Address, as well as Station Order Changes.

Token Ring ring station order table

An ordered list of the stations on the monitored rings.

Token Ring ring station table

A list of ring station entries. An entry exists for each station that is currently or has previously been detected as being physically present on the ring.

Token Ring ring station config control table

A list of ring station configuration control entries. Each entry controls the management of stations by a probe. One entry exists in this table for each active station in the ring station table.

You can use an external RMON probe for full RMON support.

Access to RMON data is available only via an SNMP management application that supports RFC 1757 and RFC 1513. You cannot access RMON via the Catalyst 5000 series switch console interface; however, the console statistics provide similar information. For full utilization of RMON data, you should use Cisco's TrafficDirector.

SPAN Support

To aid in network management, the Catalyst 5000 series Token Ring module allows you to perform active port monitoring. Active port monitoring copies traffic from a Token Ring port to a Token Ring SPAN port within the switch. You can then attach an external Token Ring monitor (network analyzer) or RMON probe to the SPAN port.

Note Forwarding to the SPAN port takes place independently of the normal forwarding.

Soft Error Monitoring and Remove Adapter Support

The Catalyst 5000 series Token Ring module software Release 3.3(1) and later performs error detection and isolation by monitoring the Report Soft Error MAC frames generated by stations on each port. Soft errors occur during normal ring operation and do not typically disrupt traffic on the ring. However, soft errors can occur at a rate that could potentially degrade the performance of the ring.

Using the soft error monitoring feature, you can configure soft error thresholds and sampling intervals for a port. During the interval you define, the Catalyst 5000 series Token Ring module monitors the stations on the port and, if the threshold is exceeded, can be configured to generate a trap indicating the port number and station on which the threshold was exceeded. If necessary, you can issue a Remove Ring Station MAC frame to remove the station from the ring.

In summary, the Catalyst 5000 series Token Ring module performs the following tasks:

Monitors the Report Soft Error MAC frames generated by stations on each port, collects the data from each soft error frame, and generates a trap containing the port number and station where the user-defined soft error threshold is exceeded.
Reports the soft error monitoring statistics via the console and SNMP.
Provides the ability to issue a Remove Ring Station MAC frame to remove a station that is reporting a high level of errors or is not authorized to be on a ring.

Token Ring Module Requirements

Before installing a Catalyst 5000 series Token Ring module, ensure that your existing system components meet the following minimum requirements for compatibility:

Supervisor Engine II or higher is installed and contains a minimum of 16 MB of dynamic random-access memory (DRAM).
Supervisor engine module software, Version 3.1 or later.

Note Soft error monitoring and remove adapter support requires Token Ring software Release 3.3(1) or later and supervisor engine module software Release 5.1(1) or later.

Note The software images containing the latest upgrades and modifications are released regularly to provide the optimum software available. Cisco Systems strongly recommends that you check Cisco Connection Online at http://www.cisco.com for the latest released software image.

VLAN Trunk Protocol, Version 2.

For information on enabling and disabling VTP V2, see the latest release of the Catalyst 5000 Series Command Reference.

Token Ring Module Physical Characteristics

The following are the technical specifications for the 16-port Token Ring module:

Table 1 Token Ring Module Specifications

Description	Specification
Dimensions (H x W x D)	1.17 x 14.4 x 16.0 in (2.9 x 36.58 x 40.64 cm)
Weight	3.9 lb (1.45 kg)
Environmental Conditions Operating temperature Nonoperating temperature Humidity	32 to 104° (0 to 40°C) -40 to 167°F (-40 to 75°C) 10 to 90%, noncondensing
Connectors	16 RJ-45 IEEE 802.5 Token Ring UTP/STP
Frame processing	Source-route, source-route transparent, source-route switching
Network management	SNMP2 agent
Agency Approvals: Safety EMI2	UL 1950, CSA-C22.2 No. 950, IEC 950, EN 60950 FCC 15J Class A, VCCI CE II, CE Mark, EN 55022 Class B, CISPR 22 Class B

Maximum Configuration

Depending on the Catalyst 5000 series switch model that you are using, there are up to 11 interface slots available on the switch. Regardless of the Catalyst 5000 series switch, interface slot 1 supports a supervisor engine module. Slot 13 on the Catalyst 5500 switch is reserved for the ATM Switch Processor (ASP) module. All other slots support any combination of network interface switching modules or provides maximum port densities of up to 176 Token Ring interfaces.

Status and Activity Indicators

The Catalyst 5000 series Token Ring module has LEDs that indicate the status and activity of the module and its ports. There is one LED associated with the Token Ring module and two LEDs associated with each of the 16 ports: Status and Activity.

For information on reading the Token Ring module and port LEDs, see the "Troubleshooting the Token Ring Module" section.

Planning for Installation

Before installing the Catalyst 5000 series Token Ring module, read this section carefully, it contains information on pre-installation planning.

Note Before installing the Catalyst 5000 series Token Ring module, read the "Translated Safety Warnings" section on page 139.

This section discusses the following topics:

Preparing Network Connections
Following Safety Recommendations
Hot-Swapping Overview
Avoiding Problems When Inserting and Removing a Switching Module

Preparing Network Connections

When preparing your site for network connections to the switch, you need to consider a number of factors related to each type of interface:

Type of cabling required for each type (fiber or twisted-pair cabling)
Distance limitations for each signal type
Specific cables you need to connect each interface
Any additional interface equipment you need, such as transceivers and converters

Before installing the switch, have all additional external equipment and cables on hand. If you intend to build your own cables, refer to the cable pinouts in the "Token Ring Cabling Recommendations" section. For ordering information, contact a customer service representative.

Token Ring Cabling Recommendations

The following tables contain the maximum supported lobe lengths. The maximum lengths reflect the longest lengths supported by the transmission characteristics of IEEE 802.5-compliant adapters.

The recommended distances for the various cable types are set by North American and international commercial building wiring standards. These standards state that standards-compliant horizontal copper cabling shall not exceed 295 feet (90 m) leaving 33 feet (10 m) total for required patch cabling in both the office and telecommunications closet. It is good practice to follow the cabling standards guidelines when installing building cabling to help ensure a longer useful life for your cabling infrastructure, migration to new technologies, and maximum flexibility for the network configuration.

Note The distance and rate limits discussed in this section are the IEEE recommended maximum speeds and distances for signaling. However, if you understand the electrical problems that may arise and can compensate for them, you should get good results with rates and distances greater than those described here, but you do so at your own risk.

Table 1 lists distance limits guidelines for planning your network connections before installation.

Table 2 Copper Cable Types

Cable Type	Impedance
1 and 1A	150 ohms
2 and 2A	150 ohms
8	150 ohms
9	150 ohms
3	100 ohms
Category 3	100 and 120 ohms
Category 4	100 and 120 ohms
Category 5	100 and 120 ohms

Cabling Length Recommendations for Dedicated-Media LAN Segments

The IBM Token Ring network dedicated-media connections support only one attached entity per connection.

In a Token Ring network, the section of cable that attaches a device to an access unit is called a lobe.

For all supported cable types except optical fiber, the recommended maximum cable lobe length is 625 feet (190 m) plus a 33 feet (10 m) total allowance for the patch cords in the office and the telecommunications closets. For optical fiber, the recommended maximum cable lobe length is 2000 m (6562 feet).

Table 3 and Table 4 specify the maximum supported lobe lengths for the following types of cables. An additional 10 m (33 feet) per lobe length is allowed to accommodate patch cables, unless otherwise specified.

150-Ohm, shielded media lobe lengths cable
Lobe lengths for 100- or 120-ohms, shielded or unshielded cable

Table 3 Lobe Lengths for 150-ohms Shielded Media

Ring Speed Types 1 and 1a, Types 2 and 2a Type 8 Type 9

4 Mbps

2460 feet (750 m)

1234 feet (376 m)

1640 feet (500 m)

16 Mbps

952 feet (290 m)

480 feet (146 m)

656 feet (200 m)

Note Subtract 33 feet (10 m) from the allowed Type 1 or 2 distance each time an 8-feet (2.4-m) patch cable is replaced by a Type 6, 30-feet (9-m) patch cable on that lobe.

Table 4 Lobe Lengths for 100- and 120-ohms, Shielded or Unshielded Cable

Ring Speed 100-ohms
Type 3 100-ohms Category 3 100- or 120-ohms Category 4 100- or 120-ohms Category 5

4 Mbps

328 feet (100 m)

820 feet (250 m)

1148 feet (350 m)

1148 feet (350 m)

16 Mbps

Not Supported

328 feet (100 m)

656 feet (200 m)

656 feet (200 m)

Cable Length and Lobe Wiring Rules for Shared-Media LAN Segments

The types of cables that can be used are the same as those described above for dedicated-media segments. The acceptable distances are defined by the hub or concentrator attached to the Catalyst 5000 series Token Ring module port.

Number of Attaching Devices

A Token Ring network supports up to 260 attached devices or nodes on a single network when using 150-ohms shielded media (type 1, 1A, 2, or 2A). When cable segments in the network are 100 or 120 ohms, this number is decreased to 132 (72 if using any 4-Mbps-only adapters or filters).

Twisted-Pair Cable Pinouts

When connecting devices to the Token Ring ports on the Catalyst 5000 Token Ring module, you must use a straight-through 100-ohms or 120-ohms cable.

The Catalyst 5000 Token Ring module RJ-45 connector makes ground available on the shield and on pins 1, 2, 7, and 8. Shielded cables provide continuity for the ground-to-any shielded connector on the other end of the cable.

Figure 4 and Figure 5 illustrate the straight-through 100-ohms and 120-ohms cable and the 150-ohms data connector-to-RJ-45 straight-through cable.

Figure 4 Straight-Through Cable

Figure 5 150-ohms Data Connector-to-RJ-45 Straight-Through Cable

Token Ring Connection Equipment

To connect to a Token Ring network, use RJ-45 male connectors (Figure 6).

Figure 6 Token Ring UTP RJ-45 Interface Cable Connectors

Following Safety Recommendations

Before you begin installing the Catalyst 5000 Token Ring module, review the safety and electrostatic (ESD)-prevention guidelines in this section to avoid injuring yourself or damaging the equipment.

Safety with Electricity

Follow these guidelines when working with any equipment powered by electricity:

Before beginning any procedures requiring access to the unit interior, locate the emergency power-off switch for the room in which you are working.
Before working on the equipment, unplug the power cord.
Disconnect all power before doing the following:

Installing or removing a chassis
Working near power supplies
Performing a hardware upgrade

Do not work alone when potentially hazardous conditions exist.
Never assume that power is disconnected from a circuit. Always check that the power is disconnected from a circuit.
Look carefully for possible hazards in your work area, such as moist floors, ungrounded power extension cables, and missing safety ground wires.
If an electrical accident occurs, proceed as follows:

Use caution.
Unplug the power cord.
If possible send another person to get medical aid. Otherwise, assess the victim's condition and then call for help.
Determine if the victim needs rescue breathing or external cardiac compressions, then take appropriate action.

Before working on equipment that is connected to power lines, remove jewelry (including rings, necklaces, and watches). Metal objects will heat up when connected to power and ground and can cause serious burns or weld the metal object to the terminals.

Unplug the power cord before you work on a system that does not have an on/off switch.

Preventing ESD

ESD damage occurs when electronic devices or components are improperly handled. This damage results in complete or intermittent failures. The supervisor engine and switching modules each consist of a printed circuit board fixed in a metal carrier. Electromagnetic interference (EMI) shielding, connectors, and a handle are integral components of the carrier. Although the metal carrier helps protect modules from ESD, use a preventive antistatic strap when you handle the supervisor engine or switching modules. Hold the carriers by the handles and the carrier edges only; never touch the modules or connector pins.

This equipment is intended to be grounded. Ensure that the host is connected to earth ground during normal use.

Guidelines for preventing ESD damage are the following:

Always use an ESD wrist strap or ankle strap, and ensure that it makes good skin contact.
When removing the supervisor engine or switching modules, connect the equipment end of the strap to one of the captive installation screws on an installed switching module, power supply, or fan assembly (Figure 7). When replacing internal components, such as the supervisor engine, that are accessible from the rear of the chassis, connect the strap to an unpainted inner surface of the chassis, such as the inner frame that is exposed when a module is removed.
When installing a supervisor engine or switching module, use the ejector levers to properly seat the bus connectors in the backplane, then tighten both captive installation screws. These screws prevent accidental removal, provide proper grounding for the system, and help to ensure that the bus connectors are seated in the backplane.
When removing a supervisor engine or switching module, use the ejectors levers to release the bus connectors from the backplane. Grasp the captive screws and pull out the carrier slowly, placing your hand along the bottom of the carrier to guide it straight out of the slot.
Hold carriers by the handles and carrier edges only; avoid touching the module or any connector pins.
When removing a switching module, place the printed circuit board side up on an antistatic surface or in a static shielding bag. If the component will be returned to the factory, immediately place it in a static shielding bag.
Handle bare boards by the edges only.

Figure 7 Placement of ESD Wrist Strap

Hot-Swapping Overview

The Catalyst 5000 series switching modules support hot swapping. The hot-swapping feature enables you to install, remove, replace, and rearrange the switching modules without turning off the system power. When the Catalyst 5000 series switch detects that a switching module has been installed or removed, it automatically runs diagnostic and discovery routines, acknowledges the presence or absence of the switching module, and resumes the system operation without any operator intervention.

The supervisor engine module and each switching module contain a bus-type connector that connects with the system backplane. Each card connector consists of a set of tiered pins, in three lengths. The pins send specific signals to the system as they make contact with the backplane of the Catalyst 5000 series switch. The system assesses the signals it receives and the order in which it receives them to determine what event is occurring and what task it needs to perform, such as reinitializing new interfaces or shutting down removed interfaces.

For example, when inserting your Catalyst 5000 series Token Ring module, the longest pins make contact with the backplane first and the shortest pins make contact last. The system recognizes the signals and the sequence in which it receives them. The system expects to receive signals from the individual pins in this logical sequence, and the ejector levers help to ensure that the pins mate in this sequence.

When you remove or insert a switching module, the backplane pins send signals to notify the system. The system then:

1. Rapidly scans the backplane for configuration changes.

2. Initializes the newly inserted switching module, notes any removed interfaces, and places them in the administratively shut-down state.

3. Brings all previously configured interfaces on the switching module back to the state they were in when they were removed. Any newly inserted interfaces are put in the administratively shutdown state, as if they were present (but unconfigured) at boot time. If a similar switching module type has been reinserted into a slot, then its ports are configured and brought on line up to the port count of the original switching module.

When you insert a new switching module, the system runs a diagnostic test on the new interfaces and compares them to the existing configuration. If this initial diagnostic test fails, the system remains off line for another 15 seconds while it performs a second set of diagnostic tests to determine whether or not the switching module is faulty and if normal system operation is possible.

If the second diagnostic test passes, which indicates that the system is operating normally and the new switching module is faulty, the system resumes normal operation but leaves the new interfaces disabled. If the second diagnostic test fails, the system crashes, which usually indicates that the new switching module has created a problem in the bus and should be removed.

To avoid erroneous failure messages, allow at least 15 seconds for the system to reinitialize and note the current configuration of all interfaces before you remove or insert another switching module.

Avoiding Problems When Inserting and Removing a Switching Module

Use the ejector levers (Figure 8) to align and seat the card connectors in the backplane. Failure to use the ejector levers and insert the switching module properly can disrupt the order in which the pins make contact with the backplane.

Before installing the Token Ring module, carefully review the instructions in the "Installing the Token Ring Module" section and the "Removing Switching Modules or Module Fillers" section. Also review the following list of examples of incorrect insertion practices and results that you want to avoid when installing the Token Ring module.

When installing the Token Ring module:

Do not use the faceplate to force a switching module all the way into the slot. This action can pop the ejector levers out of their springs. If you then try to use the ejector levers to seat the switching module, the first layer of pins (which are already mated to the backplane) can disconnect and then remate with the backplane, which the system interprets as a card failure.
Do not use the faceplate to force or slam the switching module all the way into the slot. This action can also damage the pins on the card connectors if they are not aligned properly with the backplane.
Do not use the faceplate (rather than the ejector levers) to seat the switching module in the backplane because you may need to pull the switching module back out and push it in again to align it properly. Even if this action does not damage the connector pins, the pins mating with and disconnecting from the backplane will cause the system to interpret a card failure. Using the ejector levers ensures that the card connector mates with the backplane in one continuous movement.
Do not use the faceplate to insert or remove a switching module or fail to push the ejector levers to the full 90-degree position. This action can leave some (not all) of the connector pins mated to the backplane, a state which will suspend the system. Using the ejector levers and making sure that they are pushed fully into position ensures that all three layers of pins are mated with (or free from) the backplane.

It is also important to use the ejector levers when removing a switching module to ensure that the card connector pins disconnect from the backplane in the logical sequence expected by the system. Any supervisor engine module or switching module that is only partially connected to the backplane can hang the bus. Detailed steps for correctly performing hot swap are included in the "Installing the Catalyst 5000 Series Token Ring Module" section.

All Catalyst 5000 series switching modules support hot swapping. The supervisor engine module is a required system component. Removing a supervisor engine module while the system is operating will cause the system to halt.

Installing the Catalyst 5000 Series Token Ring Module

This section explains the process you should follow to install the Catalyst 5000 series Token Ring module.

Before installing the Token Ring module, ensure that you have read the information in the "Planning for Installation" section.

Do not work on the system or connect or disconnect cables during periods of lightning activity.

This section discusses the following topics:

Required Tools
Removing Switching Modules or Module Fillers
Installing the Token Ring Module
Hot-Swapping Screen Display Samples

Do not touch the power supply when the power cord is connected. For systems with a power switch, line voltages are present within the power supply even when the power switch is off and the power cord is connected. For systems without a power switch, line voltages are present within the power supply when the power cord is connected.

Required Tools

To install the Catalyst 5000 Token Ring module, you will need the following tools:

3/8-inch flat-blade screwdriver to tighten or loosen the captive installation screws
ESD cord and wrist strap
Antistatic mat, foam pad, or bag

Removing Switching Modules or Module Fillers

If a switching module or filler (blank) module exists in the slot in which you are planning to install the Catalyst 5000 Token Ring module, remove the existing item before installing the Catalyst 5000 Token Ring module. If there is no switching module or switching module filler in the slot in which you are planning to install the Catalyst 5000 Token Ring module, proceed to the "Installing the Token Ring Module" section.

Ultimate disposal of this product should be handled according to all national laws and regulations.

Figure 8 Ejector Levers and Captive Installation Screws (Supervisor Engine Module Shown)

Do not completely loosen one captive installation screw at a time. Attempting to completely loosen one captive installation screw at a time will cause damage to the thread. Always alternate between loosening the left screw and then loosening the right screw.

To remove the existing module or module filler:

Step 1 Put on an ESD-preventive wrist or ankle strap and connect the equipment end of the strap to the metal case of the Catalsyt 5000 Series switch in which you are installing the module.

Step 2 Determine the slot for the Token Ring module and ensure that there is enough clearance to accommodate any interface equipment that you connect directly to the Token Ring module ports. If possible, place the switching module between empty slots that contain only switching module filler plates.

Step 3 Using a flat-blade screw driver, turn the captive installation screw on the left side of the carrier counter-clockwise for two full turns.

Always use the ejector levers (Figure 8 shows the ejector levers) when installing or removing switching modules. A module that is partially seated in the backplane will cause the system to halt and subsequently crash.

Step 4 Using a flat-blade screw driver, turn the captive installation screw on the right side of the carrier counter-clockwise two full turns.

Step 5 Repeat steps 3 and 4 until you have completely loosened the captive installation screws.

Step 6 Place your thumbs on the left and right ejector levers and simultaneously push both the left and right levers to release the switching module or module filler from the backplane connector.

Step 7 Grasp the switching module or module filler with one hand and place your other hand under the carrier to support and guide the module out of the slot.

Step 8 Keeping the module or module filler at a 90-degree orientation to the backplane, carefully pull the module or module filler straight out of the slot, keeping your other hand under the carrier to guide it.

Note If you are performing a hot swap, the console displays the message "Module n has been removed." However, this message does not appear if you are connected to the Catalyst 5000 through a Telnet session.

Step 9 If you have removed a switching module, place the removed module on an antistatic mat or antistatic foam, or immediately install it in another slot.

Step 10 If you are not installing a switching module in the empty slot immediately, install a switching module filler (part number 800-00292-01) to keep dust out of the chassis and to maintain proper airflow through the switching module compartment.

Never leave a switching module slot empty. Always ensure that a switching module or a switching module filler is installed in an empty slot to maintain the proper flow of cooling air across the modules.

Installing the Token Ring Module

You can install the Catalyst 5000 series Token Ring module in any of the module slots except slot 1, which is reserved for the supervisor engine module or slot 13 on the Catalyst 5500 switch which is reserved for the ASP module. Depending on the model of the Catalyst 5000 series switch you are using, the module slots are numbered 1 through 13 from the top to bottom when viewing the Catalyst 5000 series switch from the rear (Figure 9).

Slot 1 contains the supervisor engine module, which is a required system component, and if you are using a Catalyst 5500 switch, slot 13 is reserved for the ASP module. Switching modules or switching module fillers, which are blank switching module carriers, are installed in the slots without modules to maintain consistent airflow through the switching module compartment.

Figure 9 Slot Numbers on the 5-slot Catalyst 5000

When installing the Catalyst 5000 series Token Ring module, handle the module by the carrier edges only to prevent ESD damage. Make sure to avoid touching the card or connector pins.

To install the Token Ring module:

Step 1 Hold the switching module handle with one hand and place your other hand under the carrier to support the switching module. Avoid touching the card.

Step 2 Aligning the notch on the sides of the switching module with the grooves in the slot, place the back of the switching module in the slot (Figure 10).

Figure 10 Module Installation in the 5-slot Catalyst 5000

Step 3 Keep the module at a 90-degree angle to the backplane and carefully slide the switching module into the slot until the module faceplate makes contact with the ejector levers.

Do not force the Token Ring module into the slot. If the module does not slide in easily, make sure that it is properly aligned.

Step 4 Using the thumb and forefinger of each hand, simultaneously push in the left and right levers to fully seat the module in the backplane connector.

Note If you are performing a hot swap, the console displays the message, "Module n has been inserted." However, this message does not appear if you are connected to the Catalyst 5000 through a Telnet session.

Step 5 Using a flat-blade screwdriver, turn the captive installation screw on the left side of the carrier clockwise two full turns.

Step 6 With the screwdriver, turn the captive installation screw on the right side of the carrier clockwise two full turns.

Completely tightening one captive installation screw at a time will cause damage to the thread. Always alternate between turning the left screw and turning the right screw.

Step 7 Repeat steps 5 and 6 until the captive installation screws are tight. Do not use excessive force to tighten the screws.

Step 8 Attach network interface cables or other devices to the interface ports.

Step 9 Use the set interface command facility to configure the new interfaces. This configuration does not have to be done immediately, but the interfaces will not be available until you configure them. For information on configuring the new interfaces, see the Catalyst 5000 Series Advanced Software Configuration Guide.

Hot-Swapping Screen Display Samples

When you remove and replace the Catalyst 5000 series switching modules, the system provides status messages on the console screen. These messages are for information use only.

In the following display example, using the show system and show module commands, you can follow the events that are logged by the system when a switching module is removed from slot 4. When the show port command is used to query the module, the system reports notconnect. When the module is reinserted, the system marks the module as ok.

 
Console> (enable) show system 

 
PS1-Status PS2-Status Fan-Status Temp-Alarm Sys-Status Uptime d,h:m:s Logout 

 
---------- ---------- ---------- ---------- ---------- -------------- --------- 

 
ok         none       ok         off        ok         3,02:08:32     20 min 

 
PS1-Type   PS2-Type   Modem   Baud  Traffic Peak Peak-Time 

 
---------- ---------- ------- ----- ------- ---- ------------------------- 

 
WS-C5008A  none       disable  9600   0%      0% Mon Apr 5 1999, 12:31:27 

 
System Name              System Location          System Contact 

 
------------------------ ------------------------ ------------------------ 

 
Console> (enable) 

 
Console> (enable) show module 

 
Mod Slot Ports Module-Type               Model               Status 

 
--- ---- ----- ------------------------- ------------------- -------- 

 
1   1    0     Supervisor III            WS-X5530            ok 

 
2   2    12    10/100BaseTX Ethernet     WS-X5213            ok 

 
3   3    16    Token Ring                WS-X5030            ok 

 
Mod Module-Name         Serial-Num 

 
--- ------------------- -------------------- 

 
1                       00009979008 

 
2                       00003631705 

 
3                       00007382783 

 
Mod MAC-Address(es)                        Hw     Fw         Sw 

 
--- -------------------------------------- ------ ---------- ----------------- 

 
1   00-90-d9-d3-70-00 to 00-90-d9-d3-73-ff 1.8    3.1.2      5.1(0.56) 

 
2   00-60-5c-c3-49-14 to 00-60-5c-c3-49-1f 1.3    1.4        5.1(0.56) 

 
3   00:05:77:06:29:af to 00:05:77:06:29:bf 1.1    1.0(117)   3.3(1) 

 
Mod Sub-Type Sub-Model Sub-Serial Sub-Hw 

 
--- -------- --------- ---------- ------ 

 
1   EARL 1+  WS-F5520  0007601847 1.0 

 
Console> (enable) 

 
Console> (enable) show port 3/10 

 
Port  Name               Status     Vlan       Level  Duplex Speed Type 

 
----- ------------------ ---------- ---------- ------ ------ ----- ------------ 

 
 3/10                    inactive   1003       normal   auto  auto TokenRing 

 
Port   Trap      IfIndex 

 
-----  --------  ------- 

 
 3/10  disabled  29 

 
Last-Time-Cleared 

 
-------------------------- 

 
Mon Apr 5 1999, 12:31:27 

 
Console> (enable) 

Customizing the Token Ring Module Configuration

The Catalyst 5000 series Token Ring module is shipped with default configuration parameters and can function with these defaults. Therefore, you may not have to configure the module for it to work in your network. However, if you want or need to alter the configuration of the Token Ring module, you can do so.

This section describes how to use the command-line interface (CLI) to configure the ports on the Token Ring switching module. This section also contains information about STPs and Token Ring VLANs. For additional information on the CLI, refer to the Catalyst 5000 Series Command Reference.

Note For definitions of all the commands specific to the Token Ring module and existing Catalyst 5000 series switch commands that have been modified for the Token Ring module, see the "Catalyst 5000 Series Token Ring Module Command Reference" section.

This section discusses the following topics:

Default Configuration
Entering Enable Privilege Mode
Configuring Token Ring Port Parameters
Enabling and Disabling ARE Reduction
Configuring VLANs
Configuring STP
Configuring Soft Error Monitoring
Monitoring Network Traffic
Configuring Filters

Note If you have not already configured the interface for the Token Ring module, you may want to do so. This configuration does not have to be done immediately, but the interfaces will not be available until you configure them. For information on configuring the new interfaces, see the Catalyst 5000 Series Advanced Software Configuration Guide.

Default Configuration

The default values of the Token Ring module features are:

All ports are enabled
All ports are assigned to the default TrCRF
No port name is configured for any port
Priority level for all ports is set to normal
Transmission speeds for the ports is set to auto-detect
Transmission modes for the ports is set to auto
Transmission threshold is 3
Minimum transmit setting is 4
STP is enabled for all ports
ARE reduction is enabled
Soft error monitoring is disabled

Entering Enable Privilege Mode

Before you can customize certain parameters of the Token Ring module, you must invoke the privilege mode of the Catalyst 5000 series switch. When in privilege mode, you can issue commands to configure or troubleshoot the system.

To enter privileged mode:

Step 1 From the Console> prompt, type enable. You are prompted for your password.

Step 2 Type your password and press Enter. The Console> prompt now indicates that you are in enable mode by displaying (enable) next to the console prompt.

Note By default, there is no password configured for the Catalyst 5000 series switch.

For more information on configuring the Token Ring interface parameters, see the "Configuring Token Ring Port Parameters" section.

Configuring Token Ring Port Parameters

This section contains information on the following topics:

Setting the Port Name
Setting the Frame Priority Levels
Setting the Port Speed
Setting the Port Transmission Mode
Setting Early Token Release
Setting Address Recognized/Frame Copied Bits
Setting Configuration Loss Thresholds
Verifying the Token Ring Port Configuration
Troubleshooting a Faulty Port Status

Note If you change certain configuration parameters of a connected port, the port will close and reopen and you will lose all address information and statistics for that port.

Setting the Port Name

By default, no names are assigned to the ports on the Catalyst 5000 series Token Ring module. However, you can assign names to each of the ports on your Token Ring module using the set port name command.

To assign a name to a port on the module, issue the following command in privileged mode:

: set port name mod_num/port_num name

After entering the set port name command, you see a display similar to the following:

 
Console> (enable) set port name 4/1 Print-1st Floor

 
Port 4/1 name set.

 
Console> (enable) set port name 4/2 Server 1

 
Port 4/2 name set.

Setting the Frame Priority Levels

There are two types of frame priorities that you can set for a port.

Priority threshold—Highest Token Ring frame priority in the Frame Control Field of the frame that the switch should place in the low-priority transmit queue. The default priority queue threshold is 3.
Minimum transmit priority—Minimum reservation priority used when requesting a token on a busy ring. The default minimum frame priority to be used is 4.

To set the frame priority levels for a port, issue the following command in privileged mode:

: set tokenring priority mod_num/port_num {threshold 0-7 | minxmit 0-6}

After entering the set tokenring priority command, you see a display similar to the following:

 
Console> (enable) set tokenring priority 4/2 threshold 6

 
Port 2 priority threshold set to 6.

 
Console> (enable) set tokenring priority 4/2 minxmit 5

 
Port 2 priority minxmit set to 5.

Setting the Port Speed

The speed of the port is in megabits per second (Mbps). The Token Ring module ports can be set to 4 or 16 Mbps transmission speeds. The default speed, auto, enables the interfaces to automatically configure themselves to operate at the proper speed (4 or 16 Mbps). However, you can configure the port speed if necessary.

To set the transmission speed for a Token Ring module port, issue the following command in privileged mode:

: set port speed mod_num/port_num {4 | 16 | auto}

After entering the set port speed command, you see a display similar to the following:

 
Console> (enable) set port speed 4/1 4

 
Port 4/1 speed set to 4Mbps.

 
Console> (enable) set port speed 4/2 16

 
Port 4/2 speed set to 16Mbps.

 
Console> (enable) set port speed 4/3 auto

 
Port 4/3 speed set to auto detect.

 
Console> (enable)

Note Closing and opening the port on an existing ring at a different transmission speed from which the ring is currently operating will cause the port to issue a beacon on that ring.

Setting the Port Transmission Mode

The ports of the Catalyst 5000 series Token Ring module are capable of operating in half duplex mode or full duplex mode. The port can behave as either a concentrator port or an end station. The default mode, auto, enables the port to detect the transmission mode it needs to use. However, you can configure the mode if necessary.

To set the transmission mode being used by a port, issue the following command in privileged mode:

: set tokenring portmode mod_num/port_num {auto | fdxcport | hdxcport | fdxstation |
hdxstation | riro}

After entering the set tokenring portmode command, you see a display similar to the following:

 
Console> (enable) set tokenring portmode 4/2 fdxcport

 
Port 3/2 mode set to fdxcport

 
Console> (enable)

Note The Ring in (RI) / Ring out (RO) parameter applies to the ports on a fiber Token Ring module only.

Setting Early Token Release

The Token Ring module interface ports support early token release when transmitting frames. Early token release is a technique used in Token Ring networks that allows a station to release a new token onto the ring immediately after transmitting, instead of waiting for the first frame to return. Early token release increases the total bandwidth on the ring. All ports, by default, are enabled to use Early Token Release.

To enable or disable the early token release feature on a Token Ring module ports, issue the following command in privileged mode:

: set tokenring etr mod_num/port_num {enable | disable}

After entering the set tokenring etr command, you see a display similar to the following:

 
Console> (enable) set tokenring etr 4/1 enable

 
Port 4/1 Early Token Release enabled.

 
Console> (enable)set tokenring etr 4/2 disable

 
Port 4/2 Early Token Release disabled.

Note Early Token Release is valid for 16 Mbps media only. If the Early Token Release is enabled and the media speed is 4 Mbps, the switch will force Early Token Release to be disabled.

Setting Address Recognized/Frame Copied Bits

Using the set tokenring actbits command, you can specify if and how the AC bits should be set on LLC frames. When local address learning is enabled on a Token Ring port, the default is disable. When local address learning is disabled on a Token Ring port, the default is always.

For information on setting AC bits and enabling and disabling local address learning, see the "Handling Frames Transmitted with Invalid Source MAC Addresses" section.

To configure how the AC bits will be set for a port, issue the following command in privileged mode:

: set tokenring acbits mod_num/port_num {enable | disable | sronly | never | always}

After entering the set tokenring acbits command, you see displays similar to the following:

 
Console> (enable) set tokenring acbits 3/2 always 

 
Warning: Disable Local learning: 3/2 

 
Port 3/2 acbits always 

For a complete description of the syntax of the set tokenring acbits command, see the "Catalyst 5000 Series Token Ring Module Command Reference" section.

Setting Configuration Loss Thresholds

Configuration loss occurs when a port completes a connection, allows data traffic to flow, and subsequently closes. The configuration loss threshold is used to control the number of configuration losses that can occur within a specified time. When the threshold is exceeded, the port is disabled and must be enabled using the set port enable command or an SNMP manager. The valid range for the configuration loss threshold is 1 through 100. The default is 8.

To set and verify the configuration loss threshold for a port, issue the following command in privileged mode:

: set tokenring configloss mod_num/port_num {threshold <1..100> | interval <1..9999>}

After entering the set tokenring configloss command, you see a display similar to the following:

 
Console> (enable) set tokenring configloss 4/2 threshold 50

 
Port 4/2 configloss threshold set to 50.

 
Console> (enable) set tokenring configloss 4/2 interval 20

 
Port 4/2 configloss interval set to 20.

Note To view reason codes and a counter of the current number of configuration loss events, issue the show tokenring command. For a complete description of the show tokenring command and its parameters, see the "Catalyst 5000 Series Token Ring Module Command Reference" section.

Verifying the Token Ring Port Configuration

After configuring the Token Ring ports, you can verify the configuration using the following commands:

To display general port configuration, such as the port name, status, and type, use the show port mod_num/port_num command.
To display Token Ring specific configuration information, use the show tokenring mod_num/port_num command.

Note You can verify the ports individually, or as a group. To view the configuration parameters for a specific port, specify the module number and port number.

After entering the show port command and specifying the module and port number, you see a display similar to the following:

 
Console> (enable) show port 3/2

 
Port  Name               Status     Vlan       Level  Duplex Speed Type

 
----- ------------------ ---------- ---------- ------ ------ ----- ------------

 
 3/2                     inactive   1003       normal   auto  auto TokenRing

 
Port   Trap      IfIndex

 
-----  --------  -------

 
 3/2   disabled  21

 
Last-Time-Cleared

 
--------------------------

 
Mon Apr 5 1999, 12:31:27

Table 4 describes the information returned by the show port command.

Table 5 Show port Command Field Descriptions

Field	Description
Port	Module and port number.
Name	Name (if configured) of the port.
Status	Status of the port (connected, notconnect, connecting, standby, faulty, inactive, shutdown, disabled, monitor, activeflt).
Vlan	VLANs to which the port belongs.
Level	Setting level for the port (normal or high).
Duplex	Duplex setting for the port (auto, full, fdx, half, hdx, a-half, a-full, a-fdx, a-hdx).
Speed	Speed setting for the port (auto, 10, 100, 155, a-10, a-100, 4, 16, a-4, a-16).
Type	Port type (10BaseT, 10BaseFL MM, 100BaseTX, 100BaseT4, 100BaseFX MM, 100BaseFX SM, 10/100BaseTX, TokenRing, FDDI, CDDI, MLT3 CDDI, SDDI, SMF-FDDI, PreStd CDDI, SCF FDDI, OC3 MMF ATM, OC3 SMF ATM, OC3 UTP ATM, Route Switch).
Trap	Indicates whether a port trap is enabled or disabled.
IfIndex	Index value used with the ifIndex to uniquely identify the port.

Note For a complete description of the fields displayed if you issue the show port command without specifying a module and port number, see the Catalyst 5000 Series Command Reference.

After entering the show tokenring command and specifying a module and port number, you see a display similar to the following:

 
Console> (enable) show tokenring 3/2

 
ARE reduction is enabled

 
CRF distribution is disabled

 
Ports   Crf/Brf      Ring#      Port-Mode        Early-Token    AC-bits

 
-----   ---------    -------    -------------    -----------    --------

 
 3/2    1003/1005    0x0        auto             enabled        disabled

 
Ports   Prior-Thresh    Min-Xmit    MAC-Address         Auto-Disable-Reason

 
-----   ------------    --------    -----------------   -------------------

 
 3/2    3               4           00:05:77:06:29:b0   not-disabled

 
Ports   Cfg-Loss-Thresh  Cfg-Loss-Intvl  Cfg-Loss-Count  Cfg-Loss-Reason

 
-----   ---------------  --------------  --------------  ---------------

 
 3/2    8                1               0               none

 
Ports   Local-Learn Port-Aging

 
-----   ----------- ----------

 
 3/2    enabled     0

 
Console> (enable)

Table 5 describes the information returned by the show tokenring command issued with a module and port number specified.

Table 6 Show tokenring Command Field Descriptions

Field	Description
Ports	Module and port number.
Crf/Brf	TrCRF to which a port is assigned and the parent BRF associated with the TrCRF.
Ring	Logical ring number (in hexadecimal format) assigned to the TrCRF. Possible values are 01 through FFF.
Port-Mode	Operation mode of the port. Possible values are auto, fdx-cport, fdx-station, hdx-cport, hdx-station, and riro. Only FDX and HDX modes can be automatically detected. The operation mode of riro applies to fiber ports only.
Early-Token	Indicates whether the port is enabled for Early Token Release. Possible values are enabled and disabled. The default is enabled. Early Token Release is valid for 16 Mbps media only. If the Early Token Release is enabled and the media speed is 4 Mbps, the switch will force Early Token Release to be disabled.
AC-bits	Indicates the method used for setting the address recognized (A) and frame copied (C) bits for the port. When local address learning is enabled on a port, the default is disabled. When local address learning is disabled on a port, the default is always.
Prior-Thresh	Highest Token Ring frame priority in the Frame Control field of the frame that the switch should place in the low-priority transmit queue. Possible values are 0 through 7. The default is 3.
Min-Xmit	Minimum reservation priority used when requesting a token on a busy ring. Possible values are 0 through 6. The default is 4.
MAC-Address	MAC address of the port.
Auto-Disable- Reason	Indicates whether the port is currently disabled and if so, why it is disabled. Possible values are not-disabled, unknown, speed-error, and remove-received.
Cfg-Loss-Thresh	Value used to control the number of configuration losses that can occur within the configuration loss sampling interval. Configuration loss occurs when a port completes a connection, allows data traffic to flow, and subsequently closes. When the threshold is exceeded, the port is disabled and must be enabled via this panel or an SNMP manager. Possible values are 1 through 100. The default is 8
Cfg-Loss-Intvl	Sampling period (in minutes) used when measuring the number of configuration losses occurring. Possible values are 1 through 60. The default is 1.
Cfg-Loss-Count	Number of Token Ring configuration loss events after the port has completed the join process and then lost communication.
Cfg-Loss-Reason	Error code of the latest configuration loss event. Possible values are None, Wire Fault, Lobe Test Fail, TKP Frame Error, Heart Beat Fail, TXI New Station, TXI Prot Error, Speed Error, Remove Received.
Local-Learn	Indicates whether local MAC address learning is enabled or disabled.
Port-Aging	Time (in seconds) when inactive MAC addresses are removed from the port address table.

Troubleshooting a Faulty Port Status

Check the following items to help isolate the possible causes for a port to be in a faulty state.

A speed error has occurred.

A speed error occurs if there has been a mismatch of speeds between the switch ports and attached devices (for example, if you have set the port speed to 4 Mbps and the ring is 16 Mbps).

To determine if a speed error has occurred, verify that the speed set for the port, attached devices, and the ring are the same.

A remove station MAC frame has been received on the port.

Remove station MAC frames are issued by a configuration report server (CRS) running on a LAN management program and are sent to a port to instruct a ring station to remove itself from the ring.

Enabling and Disabling ARE Reduction

As explained in the "ARE Reduction" section, for parallel SRB or SRT backbones, ARE reduction ensures that the number of ARE frames generated by the switch does not overwhelm the network. Using the set tokenring reduction command, you can enable and disable ARE reduction.

ARE reduction ensures that only one ARE frame is received on each ring within each VLAN (TrBRF and TrCRF). The number of ARE frames is equal to the number of external parallel paths between the rings.

To enable ARE reduction, issue the following command in privileged mode:

: set tokenring reduction enable

To disable ARE reduction, issue the following command in privileged mode:

: set tokenring reduction disable

Configuring VLANs

A VLAN is a logical group of LAN segments, independent of physical location, with a common set of requirements. For example, several end stations might be grouped as a department, such as engineering or accounting. If the end stations are located close to one another, they can be grouped into a LAN segment. If any of the end stations are on a different LAN segment, such as different buildings or locations, they can be grouped into a VLAN that has all the same attributes as a LAN even though the end stations are not all on the same LAN segment. The information identifying a packet as part of a specific VLAN is preserved across a Catalyst 5000 series switch connection to a router or another switch if connected via trunk ports (for example, ISL).

Any VLAN can participate in the STP. Once VLANs have been established, packets are forwarded between ports belonging to the same VLAN only, unless the VLANs are joined by the bridging function to other VLANs. You can partition the ports on a single Catalyst 5000 series Token Ring module into multiple Token Ring VLANs.

Before configuring VLANs, ensure that a VTP management domain exists. For information on configuring management domains and VLANs, Catalyst 5000 Series Advanced Software Configuration Guide.

Token Ring VLANs

Within a Token Ring VLAN, logical rings can be formed by defining groups of ports that have the same ring number. In general, a TrCRF is limited to the ports in a Catalyst 5000 series switch. However, there is one exception to this rule, which is discussed in the "Adding or Changing TrCRF Parameters" section. Within the TrCRF, source-route switching is used for forwarding based on either MAC addresses or route descriptors. Frames can be switched between ports within a single TrCRF.

Multiple TrCRFs can be interconnected using a single TrBRF. The connection between the TrCRF and the TrBRF is referred to as a logical port. For source routing, the switch appears as a single bridge between the logical rings. The TrBRF can function as an SRB or SRT bridge running either the IBM or IEEE STP. If SRB is used, duplicate MAC addresses can be defined on different logical rings.

Traditionally, one instance of STP is run for each VLAN to prevent loops in the bridge topology, however, Token Ring runs an instance of STP both at the TrCRF level and the TrBRF level. The STP running at the TrCRF level removes loops in the logical ring. The TrBRF STP functions similar to the Ethernet STP, interacting with external bridges to remove loops from the bridge topology.

Certain parent TrBRF STP and TrCRF bridge mode configurations may result the logical ports (the connection between the TrBRF and the TrCRF) of the TrBRF being put in a blocked state. For more about these configurations, see the "Configuring STP" section.

For more information about Token Ring VLANs, see the "Token Ring VLANs" section.

Adding or Changing TrBRF Parameters

Using the set vlan command, you can configure a new TrBRF or change an existing TrBRF.

When configuring a TrBRF, keep the following in mind:

The VLAN number for the default TrBRF is 1005. Possible bridge number values, in hexadecimal format, are 00 through 0F. The bridge number for the default bridge is 0F.
If you set the TrBRF state to suspend, all logical ports associated with the TrBRF will be disabled and shown as inactive.
You cannot assign a TrCRF to the default TrBRF (1005). The default TrBRF can only be the parent of the default TrCRF (1003).
There are two TrBRF STP and TrCRF bridge mode configurations that will result in the logical ports (the connection between the TrBRF and the TrCRF) of the TrBRF being put in a blocked state:

The TrBRF is running the IBM STP and the TrCRF is in SRT mode.
The TrBRF is running the IEEE STP and the TrCRF is in SRB mode.

For more information about these configurations and information on manually setting the state of the logical ports of a TrBRF, see the "Setting the Port State" section.

The default STP for a TrBRF is IBM.
The Catalyst 5000 series Token Ring software Release 3.2(1) and later supports MTUs of up to 17800 bytes.

When configuring larger MTUs for the ports or TrBRFs on a Token Ring module, be aware of the following:

You cannot configure a port MTU that is greater than the MTU configured for the TrBRF to which the port belongs.
You cannot configure an LAN Emulation Client (LEC) MTU that is greater than the MTU configured for the TrBRF to which the LEC belongs.

If you reduce the MTU for a TrBRF to a value that is less than the MTU currently configured for the individual ports or LAN emulation clients (LECs) in the TrBRF, the MTU for the ports or LECs is automatically reduced to a value (1500, 4472, 8144, or 17800) that is less than that specified for the TrBRF.

To configure a new TrBRF, issue the following version of the set vlan command in privileged mode:

: set vlan vlan_num [name name] type trbrf [state {active | suspend}] [mtu mtu]
bridge bridge_number [stp {ieee | ibm}]

After entering the set vlan command, you see a display similar to the following:

 
Console> (enable) set vlan 999 name brf-999 type trbrf

 
Vlan 999 configuration successful

 
Console> (enable)

To change an existing TrBRF, issue the following command in privileged mode, changing the appropriate parameters as necessary:

: set vlan vlan_num [name name] [state {active | suspend}] [mtu mtu]
[decring decimal_ring_number][bridge bridge_number] [stp {ieee | ibm}]

Adding or Changing TrCRF Parameters

Using the set vlan command, you can configure a new TrCRF or change an existing TrCRF. There are three types of TrCRFs that you can configure in your network: undistributed, distributed, and backup.

Undistributed TrCRFs

The undistributed TrCRF is the standard type of TrCRF in the Catalyst 5000 series switch. The undistributed TrCRF is located on one switch and has a logical ring number associated with it. Multiple undistributed TrCRFs located on the same or separate switches can be associated with a single parent TrBRF. The parent TrBRF acts as a multiport bridge, forwarding traffic between the undistributed TrCRFs. Figure 11 illustrates the undistributed TrCRF.

Figure 11 Undistributed TrCRFs

Distributed TrCRFs

A distributed TrCRF contains ports on different switches as illustrated in Figure 12. By default, the Token Ring VLAN configuration of the Token Ring module has all ports assigned to the default TrCRF (1003). The default TrCRF is associated with the default TrBRF (1005). In the situation where a user has not configured the ports of a Token Ring module to be associated with a new TrCRF, traffic will be passed between the default TrCRFs located on separate switches that are connected via ISL.

While you can distribute the ports of a TrCRF across switches, we recommend that you use extreme caution when configuring a distributed TrCRF other than the default TrCRF (1003). Always ensure that there are no loops configured in your network before configuring a distributed TrCRF.

Before you can configure a distributed TrCRF, you must enable the ability to do so using the set tokenring distrib-crf command. For information on the set tokenring distrib-crf command, see the "Enabling the Ability to Configure a Distributed TrCRF" section.

Note To pass data between rings located on separate switches, you can associate the rings to the same TrBRF and configure the TrBRF for SRB.

Figure 12 Distributed TrCRF

Backup TrCRFs

The backup TrCRF enables you to configure an alternate route for traffic between undistributed TrCRFs located on separate switches that are connected by a TrBRF, should the ISL connection between the switches become inactive. Only one port per switch can be configured as part of a backup TrCRF and only one backup TrCRF can be configured for a TrBRF.

To create a backup TrCRF, you assign one port on each switch that the TrBRF traverses to the backup TrCRF. Under normal circumstances, only one port in the backup TrCRF is active. If the ISL connection between the switches become inactive, the port that is a part of the backup TrCRF on each affected switch will automatically become active, rerouting traffic between the undistributed TrCRFs through the backup TrCRF. When the ISL connection is reestablished, all but one port in the backup TrCRF will once again be disabled. Figure 13 illustrates the backup TrCRF.

Figure 13 Backup TrCRF

When configuring a TrCRF, keep the following in mind:

The VLAN number for the default TrCRF is 1003. Possible ring_number values, in hexadecimal format, are 01 through FFF.
The TrBRF to which you plan to associate the TrCRF must be configured before you configure the TrCRF.
If you set the TrCRF state to suspend, all ports associated with the TrCRF will be disabled and shown as inactive.
The default bridge mode of a TrCRF is SRB.
There are two TrBRF STP and TrCRF bridge mode configurations that will result in the logical ports (the connection between the TrBRF and the TrCRF) of the TrBRF being put in a blocked state:

The TrBRF is running the IBM STP and the TrCRF is in SRT mode.
The TrBRF is running the IEEE STP and the TrCRF is in SRB mode.

For more information about these configurations and information on manually setting the state of the logical ports of a TrBRF, see the "Setting the Port State" section.

You cannot assign a TrCRF to the default TrBRF (1005). The default TrBRF can only be the parent of the default TrCRF (1003).

To configure a new TrCRF, issue the following version of the set vlan command in privileged mode, ensuring that you specify each of the parameters that applies to the type of TrCRF you are configuring:

: set vlan vlan_num [name name] type trcrf [state {active | suspend}] [mtu mtu]
ring ring_number [decring decimal_ring_number] parent vlan_num [mode {srt | srb}]
[backupcrf {off | on}] [aremaxhop hopcount] [stemaxhop hopcount]

After entering the set vlan command, you see a display similar to the following:

 
Console> (enable) set vlan 1000 name crf-1000 type trcrf ring 001 parent 999 

 
Vlan 1000 configuration successful

 
Console> (enable)

To change an existing TrCRF, issue the following command in privileged mode, changing the appropriate parameters as necessary:

: set vlan vlan_num [name name] [state {active | suspend}] [mtu mtu] [ring ring_number]
[decring decimal_ring_number] [parent vlan_num] [mode {srt | srb}]
[backupcrf {off | on}] [aremaxhop hopcount] [stemaxhop hopcount]

Specifying a Backup TrCRF

To specify that a TrCRF is a backup TrCRF, issued the following command in privileged mode:

: set vlan vlan_num backupcrf on

After entering the set vlan command and specifying on for the backupcrf parameter, you see a display similar to the following:

 
Console> (enable) set vlan 1000 backupcrf on

 
Vlan 1000 configuration successful.

If the backup TrCRF port is attached to a Token Ring MAU, it will not provide a backup path unless the ring speed and port mode are set by another device. Therefore, it is recommended that ring speed and port mode be configured for the backup TrCRF.

Enabling the Ability to Configure a Distributed TrCRF

A distributed TrCRF is TrCRF in which ports associated with the TrCRF are located on different Catalyst 5000 series switches. Before you can configure a distributed TrCRF using the set vlan command, you must enable the ability to do so.

Use extreme caution when configuring a distributed TrCRF in your network. Ensure that no loops are configured in the network before configuring a distributed TrCRF.

To enable or disable the capability to distribute a TrCRF, issue the following command while in privileged mode:

: set tokenring distrib-crf {enable | disable}

After enabling the distribution of TrCRFs using the set tokenring distrib-crf command, you see a display similar to the following:

 
Console> (enable) set tokenring distrib-crf enable

 
WARNING:Ports will NOT be inactivated for distributed crfs. NETWORK LOOPS MAY OCCUR.

 
Console> (enable) 

Specifying All-Route Explorer and Spanning-Tree Explorer Maximum Hop Counts

You can specify the maximum hop count for all-route and spanning-tree explorer frames for each TrCRF. This limits the maximum number of hops an explorer is allowed to traverse. If a port determines that the explorer frame it is receiving has traversed more than the number of hops specified, it does not forward the frame. The TrCRF determines the number of hops an explorer has traversed based on the number of bridge hops in the route information field.

If you are configuring maximum hop counts for a TrCRF, ensure that you specify values for the aremaxhop and stemaxhop parameters when issuing the set vlan command. Valid values are 1 to 14. The default is 7.

To specify the maximum number of bridge hops to be allowed in explorer packets for a TrCRF, issue the following command in privileged mode:

: set vlan vlan_num aremaxhop hopcount stemaxhop hopcount

After entering the set vlan command and specifying hopcount values, you see a display similar to the following:

 
Console> (enable) set vlan 1000 aremaxhop 10 stemaxhop 10

 
Vlan 1000 configuration successful

Grouping Ports to a TrCRF

A TrCRF created in a management domain remains unused until it is associated with ports on the Catalyst 5000 series Token Ring module.

To group Token Ring module ports into a TrCRF, issue the following command in privileged mode:

: set vlan vlan_num mod/ports...

Note The port numbers can be entered asa range or as individual ports. Entries are separated by a comma. For example, you could enter 1/1,2/1-12,3/1-2,4/1-12.

After entering the set vlan command to group ports to a TrCRF, you see a display similar to the following:

 
Console> (enable) set vlan 1000 3/1-3

 
VLAN 1000 modified. 

Verifying Token Ring VLAN Parameters

To verify the Token Ring VLANs you have configured, issue the following command:

: show vlan [vlan_number]

After entering the show vlan command and specifying a TrBRF, you see a display similar to the following:

 
Console> (enable) show vlan 1005

 
VLAN Name                             Status    IfIndex Mod/Ports, Vlans

 
---- -------------------------------- --------- ------- ------------------------

 
1005 trbrf-default                    active    6	1003

 
VLAN Type  SAID       MTU   Parent RingNo BrdgNo Stp  BrdgMode Trans1 Trans2

 
---- ----- ---------- ----- ------ ------ ------ ---- -------- ------ ------

 
1005 trbrf 101005     1500  -      -      0x0    ibm  -        0      0

 
VLAN DynCreated

 
---- ----------

 
1005 static

 
VLAN AREHops STEHops Backup CRF 1q VLAN

 
---- ------- ------- ---------- -------

 
Console> (enable)

After entering the show vlan command and specifying a TrCRF, you see a display similar to the following:

 
Console> (enable) show vlan 1003

 
VLAN Name                             Status    IfIndex Mod/Ports, Vlans

 
---- -------------------------------- --------- ------- ------------------------

 
1003 trcrf-default               	active    7       3/1-16

 
VLAN Type  SAID       MTU   Parent RingNo BrdgNo Stp  BrdgMode Trans1 Trans2

 
---- ----- ---------- ----- ------ ------ ------ ---- -------- ------ ------

 
1003 trcrf 101003     1500  0      0x0    -      -    -        0      0

 
VLAN DynCreated

 
---- ----------

 
1003 static

 
VLAN AREHops STEHops Backup CRF 1q VLAN

 
---- ------- ------- ---------- -------

 
1003 7       7       off

 
Console> (enable)

Table 6 describes the information returned by the show vlan command.

Table 7 Show vlan Command Field Descriptions

Field	Description
VLAN	VLAN number.
Name	Name of the VLAN (if configured).
Status	Status of the VLAN (active or suspend).
IfIndex	Index value used with the ifIndex to uniquely identify the VLAN.
Mod/Ports, VLANs	Ports that belong to the VLAN.
Type	Media type of the VLAN.
SAID	Security Association ID value for the VLAN.
MTU	Maximum transmission unit size for the VLAN.
Parent	Parent VLAN, if a parent VLAN exists.
RingNo	Ring number for the TrCRF.
BrdgNo	Bridge number for the TrBRF.
Stp	STP type used on TrBRF.
BrdgMode	Bridging mode for this TrCRF. Possible values are SRB and SRT. The default is SRB. This field is valid only for TrCRFs.
Trans1	First translational VLAN used to translate FDDI to Ethernet.
Trans2	Second translational VLAN used to translate FDDI to Ethernet.
DynCreated	Dynamic creation.
AREHops	Maximum number of hops for ARE frames. Possible values are 1 through 13. The default is 7.
STEHops	Maximum number of hops for spanning-tree explorer frames. Possible values are 1 through 13. The default is 7.
Backup CRF	Whether the TrCRF is a backup path for traffic.
1q VLAN	Number of the 802.1Q VLAN.

Clearing a Token Ring VLAN

To clear the definition of a TrCRF or TrBRF, issue the following command while is privileged mode:

: clear vlan vlan_number

After entering the clear vlan command and specifying a TrCRF, you will be notified that the command will deactivate the ports on the VLAN and be prompted to continue as seen in the following display:

 
Console> (enable) clear vlan 1000

 
This command will deactivate all ports on vlan 1000

 
in the entire management domain

 
Do you want to continue(y/n) [n]?y

 
Vlan 1000 deleted.

When clearing a TrCRF, all the ports grouped to the TrCRF will become inactive and will remain inactive and associated with the TrCRF number until they are assigned to a new TrCRF.

After entering the clear vlan command and specifying a TrBRF, you will see a display similar to the following:

 
Console> (enable) clear vlan 999

 
Vlan 999 deleted

 
Console> (enable)

Note You cannot delete a TrBRF without first reassigning or clearing the TrCRFs to which it is a parent.

Configuring STP

When creating fault-tolerant internetworks, a loop-free path must exist between all nodes in a network. The algorithm performed by a STP calculates the best loop-free path throughout a switched network. Spanning-tree packets are sent and received by switches in the network at regular intervals.

The packets are not forwarded by the switches participating in the STP, but are instead used by the switches to identify the loop-free path. STP performs this function for Catalyst 5000 series switches.

The Catalyst 5000 series Token Ring module supports the following STPs:

IEEE 802.1d STP
IBM STP
Cisco STP

The Catalyst 5000 series switch uses the IEEE 802.1d and IBM STPs on TrBRFs. The STP running on the TrCRF is either the Cisco or IEEE STP, depending on the bridging mode configured for the TrCRF using the set vlan command. The default configuration has all STPs enabled.

Certain TrBRF STP and TrCRF bridge mode configurations are incompatible and result in the TrCRFs of the configuration being put in a blocked state. For more about these configurations, see the "Setting the Port State" section.

For more information on the STP activity at the TrBRF and TrCRF levels depending upon the TrBRF STP and the TrCRF bridge mode configuration, see "STP" section.

Enabling the STP

By default, STP is enabled for VLANs, however, if necessary, you can enable and disable STP for TrBRFs and TrCRFs.

Note If you disable STP participation for a TrBRF, then all TrCRFs with this TrBRF as a parent will be set to forwarding state.

To enable STP, issue the following command in privileged mode:

: set spantree enable [vlan]

After enabling STP for a VLAN, you see a display similar to the following:

 
Console> (enable) set spantree enable 1005

 
VLAN1005 bridge spanning tree enabled

 
Console< (enable)

To disable STP for a VLAN, enter the set spantree disable command:

: set spantree disable [vlan]

After disabling STP for a VLAN, you see a display similar to the following:

 
Console> (enable) set spantree disable 1005

 
VLAN1005 bridge spanning tree disabled

 
Console< (enable)

Configuring STP for a TrBRF

You can configure the type of STP to be used by a TrBRF.

Note that the following STP and bridge mode configurations are incompatible and result in logical ports being placed in a blocked state:

TrBRF is running the IBM STP and the TrCRF is in SRT mode.
TrBRF is running the IEEE STP and the TrCRF is in SRB mode.

For more information on these configurations and how to manually set the logical port state, see the "Setting the Port State" section.

To specifying a STP for a TrBRF, issue the following command in privileged mode:

: set vlan vlan_num [stp {ieee | ibm}]

After entering the set vlan command and specifying a STP, you see a display similar to the following:

 
Console> (enable) set vlan 950 stp ieee

 
Vlan 950 configuration successful

 
Console> (enable) show vlan 950

Specifying the STP Functional Address

Using the set spantree command, you can specify for a TrBRF to use the IBM bridge functional address or the IEEE Spanning Tree Protocol address.

To specify for a TrBRF running the IEEE STP to use the IBM bridge functional address instead of the IEEE STP address, issue the following command in privileged mode:

: set spantree multicast-address vlan_num ibm

Setting the Port State

Each logical port (the connection between the TrBRF and TrCRF) of a TrBRF on a switch using STP exists in one of the following five states:

Blocking
Listening
Learning (This state does not apply to the IBM STP.)
Forwarding
Disabled

The port states occur as follows:

From initialization to blocking
From blocking to listening or to disabled
From listening to learning or to disabled
From learning to forwarding or to disabled
From forwarding to disabled

When STP is enabled, every switch in the network goes through the blocking state and the transitory states at power up. If properly configured, the logical ports then stabilize to the forwarding or blocking state. However, with TrBRFs and TrCRFs, there are two exceptions to this rule that require you to manually set the state of a logical port of a TrBRF. The two exceptions are if the:

TrBRF is running the IBM STP and the TrCRF is in SRT mode.
TrBRF is running the IEEE STP and the TrCRF is in SRB mode.

Note When the above configurations occur, the logical ports are put in a blocked state and no STP is run.

You can use the set spantree portstate command to manually set the state of a logical port to blocked or forwarding mode if either of the above configurations exists.

To manually set the state of a logical port of a TrBRF, issue the following command in privileged mode:

: set spantree portstate trcrf {auto | block | forward} [trbrf]

After entering the set spantree portstate command, you see a display similar to the following:

 
Console> (enable) set spantree portstate 950 forward

 
Portstate successfully set for tokenring crf 950

 
Console> (enable)

Note If you disable the STP state for a TrBRF using the set spantree command, the logical ports of the TrBRF will be put in forwarding state regardless of the state you configured using the set spantree portstate command.

Configuring the Port Priority

The port (physical or logical) with the lowest priority value has the highest priority and will forward the spanning-tree frames. For physical ports, the possible priority range is 0 through 255 (decimal). The default is 128. For logical ports, the possible priority range is 0 through 7. The default is 4. If all ports have the same priority value, the lowest port number forwards the spanning-tree frames.

To configure the priority associated with a logical port, issue the following command in privileged mode:

: set spantree portpri trcrf_num priority

After entering the set spantree portpri command, you see a display similar to the following:

 
Console> (enable) set spantree portpri 900 50

 
Token Ring 900 port priority set to 50.

 
Console> (enable)

To configure the priority associated with a physical port, issue the following command in privileged mode:

: set spantree portpri mod_num/port_num priority

After entering the set spantree portpri command, you see a display similar to the following:

 
Console> (enable) set spantree portpri 3/4 10

 
Bridge port 3/4 port priority set to 10.

 
Console> (enable)

Configuring the Port Cost

The STP uses port path costs to determine which port (physical or logical) to select as a forwarding port. Therefore, lower numbers should be assigned to ports attached to faster media (such as full duplex), and higher numbers should be assigned to ports attached to slower media.The possible range is 1 to 65535. The default is 62. A rule of thumb for path cost is 1000 ÷ LAN speed in megabits per second.

To configure the cost associated with a physical port, issue the following command in privileged mode:

: set spantree portcost mod_num/port_num cost

To configure the cost associated with a logical port, issue the following command in privileged mode:

: set spantree portcost trcrf cost

After entering the set spantree portcost command and specifying a module number and port number, you see a display similar to the following:

 
Console> (enable) set spantree portcost 3/4 100

 
Spantree port 3/4 path cost set to 100.

 
Console> (enable)

Configuring Additional STP Parameters

You can configure additional STP parameters using the set spantree command. Table 8 lists the types of spanning tree information you can configure and the command you use.

Table 8 Spanning Tree Configuration Commands

Task Command

Set the bridge forward delay for a VLAN.

set spantree fwddelay delay [vlan]

Set the bridge hello time for a VLAN

set spantree hello interval

Set the bridge maximum aging time for a VLAN.

set spantree maxage agingtime [vlan]

Set the bridge priority for a VLAN.

set spantree priority bridge_priority [vlan]

Configure a physical port that is connected to a single workstation or PC to start faster when it is connected.

set spantree portfast mod_num/port_num {enable | disable}

Note For a complete description of the set spantree commands that differ for the Token Ring module from those described in the Catalyst 5000 Series Command Reference, see the "Catalyst 5000 Series Token Ring Module Command Reference" section.

Verifying STP Parameters

You can display the STP configuration for a specific VLAN, switching module, or port.

To verify the STP configuration information for a TrBRF or TrCRF, issue the following command:

: show spantree vlan_num

After entering the show spantree command, you will see a display similar to the following:

 
Console> (enable) show spantree 1003

 
VLAN 1003

 
Spanning tree enabled

 
Spanning tree type          ieee

 
Designated Root             00-00-00-00-00-00

 
Designated Root Priority    0

 
Designated Root Cost        0

 
Designated Root Port        1/0

 
Root Max Age   0  sec    Hello Time 0  sec   Forward Delay 0  sec

 
Bridge ID MAC ADDR          00-00-00-00-00-00

 
Bridge ID Priority          32768

 
Bridge Max Age 20 sec    Hello Time 2  sec   Forward Delay 15 sec

 
Port      Vlan  Port-State     Cost   Priority  Fast-Start  Group-Method

 
--------- ----  -------------  -----  --------  ----------  ------------

 
 3/1      1003  inactive         250        32   disabled

 
 3/2      1003  inactive         250        32   disabled

 
 3/3      1003  inactive         250        32   disabled

 
 3/4      1003  inactive         250        32   disabled

 
 3/5      1003  inactive         250        32   disabled

 
 3/6      1003  inactive         250        32   disabled

 
 3/7      1003  inactive         250        32   disabled

 
 3/8      1003  inactive         250        32   disabled

 
 3/9      1003  inactive         250        32   disabled

 
 3/10     1003  inactive         250        32   disabled

 
 3/11     1003  inactive         250        32   disabled

 
 3/12     1003  inactive         250        32   disabled

 
 3/13     1003  inactive         250        32   disabled

 
 3/14     1003  inactive         250        32   disabled

 
 3/15     1003  inactive         250        32   disabled

 
 3/16     1003  inactive         250        32   disabled

 
* = portstate set by user configuration.

 
Console> (enable)

Table 8 describes the information returned by the show spantree command.

Table 9 Show spantree Command Field Descriptions

Field	Description
VLAN	VLAN for which spanning-tree information is shown.
Spanning tree	Indicates whether STP is enabled or disabled.
Spanning tree type	STP running on the TrCRF.
Designated Root	MAC address of the designated spanning-tree root bridge.
Designated Root Priority	Priority of the designated root bridge.
Designated Root Cost	Total path cost to reach the root.
Designated Root Port	Port through which the root bridge can be reached (shown only on non-root bridges).
Root Max Age	Amount of time a BPDU1 packet should be considered valid.
Hello Time	Indicates how often the root-bridge sends BPDUs (in seconds).
Forward Delay	Indicates how much time the port spends in listening or learning mode (in seconds).
Bridge ID MAC ADDR	Bridge MAC address.
Bridge ID Priority	Bridge priority.
Bridge Max Age	Bridge maximum age (in seconds).
Hello Time	Indicates how often the bridge sends BPDUs (in seconds).
Forward Delay	Indicates how much time the bridge spends in listening or learning mode (in seconds).
Port	Port number.
Vlan	VLAN to which the port belongs.
Port-State	Indicates spanning tree port state (disabled, inactive, not-connected, blocking, listening, learning [this state does not apply to the IBM STP], forwarding, bridging).
Cost	Cost associated with the port.
Priority	Priority associated with the port.
Fast-Start	Indicates whether the port is configured to use the fast-start feature.

Configuring Soft Error Monitoring

Using the set station softerror command, you can enable or disable soft error monitoring on a Token Ring port and you can configure soft error thresholds and sampling intervals for a port. During the interval you define, the Catalyst 5000 series Token Ring module monitors the stations on the port and, if the threshold is exceeded, can be configured to generate a trap indicating the port number and station on which the threshold was exceeded. If necessary, you can issue a Remove Ring Station MAC frame to remove the station from the ring.

Enabling or Disabling Soft Error Monitoring on a Port

To enable or disable soft error monitoring on a Token Ring port, issue the following command in privileged mode:

: set station softerror mod_num | mod_num/port_num disable | enable

Note To enable soft error monitoring on all the ports of the Token Ring module, issue the set station softerror command and specify the module number of the Token Ring module.

After enabling soft error monitoring on a port using the set station softerror command, you see a display similar to the following:

 
Console> (enable) set station softerror 3/10 enable

 
Port 3/10 soft error monitoring enabled.

 
Console> (enable)

Configuring Soft Error Monitoring Error Thresholds and Sampling Intervals

To configure a soft error monitoring error threshold (the number of soft errors reported from a station connected to a port that if exceeded causes a soft error exceeded trap to be issued) and to define a sampling interval (the period, in seconds, during which the number of soft errors is monitored for each station connected to this port) issue the following command while in privileged mode:

: set station softerror mod_num[/port_num] threshold threshold_num interval int_num

The possible values for the error threshold are 1 to 255. The default is 100. The possible values for the sampling interval are 0 to 65534. The default is 60. Setting the interval to zero disables the soft error exceeded traps. Without these traps, soft errors can still be monitored via the console.

Note To set the error threshold and sampling interval for all the ports of the Token Ring module, issue the set station softerror command and specify the module number of the Token Ring module.

After configuring the error threshold and sampling interval using the set station softerror command, you will see a display similar to the following:

 
Console> (enable) set station softerror 3/10 threshold 100 interval 200

 
Port 3/10 station soft error threshold set to 100, interval set to 200

 
Console> (enable)

Verifying the Soft Error Monitoring Configuration

To verify your soft error monitoring configuration on a port, issue the following command while in privilege mode:

: show station softerror config mod_num[/port_num]

Note To view the soft error monitoring configuration for all the ports of the Token Ring module, issue the show station softerror config command and specify the module number of the Token Ring module.

After entering the show station softerror config command to verify the configuration on a port, you will see a display similar to the following:

 
Console> (enable) show station softerror config 3/10

 
Ports   Threshold Interval Status

 
-----   --------- -------- --------

 
 3/10   100       200      enabled

 
Console> (enable)

Removing an Adapter from the Network

If a station is exceeding soft error thresholds, you can issue a Remove Ring Station MAC frame to remove the station from the ring. When issuing the clear station command, enter the MAC address in non-canonical format (00:11:22:33:44:55).

: clear station mod_num/port_num mac_addr

Issuing the clear station command and specifying the MAC address or ID of a station issues a Remove Station MAC frame to that station and removes the station from the ring. Use this procedure with extreme caution.

Monitoring Network Traffic

To aid in network management, the Catalyst 5000 series Token Ring module allows you to configure a SPAN port for monitoring port traffic. This SPAN support allows you to perform active monitoring on any single Token Ring source port. Active port monitoring allows you to copy the traffic being switched by a source port to a destination port. Only the LLC traffic that is being switched by the source port is monitored when you configure active port monitoring. The MAC frames are not monitored.

For the Catalyst 5000 series Token Ring module SPAN feature to function reliably in Token Ring software releases prior to Release 3.3(1), the SPAN port and the port being monitored must be located on the same Token Ring module and the final destination for traffic received by the source port should be a port on the same Token Ring module.

When configuring SPAN for a single Token Ring source port keep in mind the following:

If the SPAN destination port is a Token Ring port, then the source port must be a Token Ring port.
Any interaction between two endstations on a shared segment that is attached to a switch port configured as a SPAN source port will not be monitored at the destination SPAN port.
For proper operation, the Token Ring module SPAN feature requires that the supervisor engine module be running software Release 4.5(1) and later.

Configuring SPAN

To configure a SPAN port, issue the following command in privileged mode, specifying the source port, the destination port, and the direction of traffic that you want to monitor that is being switched on the source port.

: set span {_mod/src_port} {dest_mod/dest_port} [rx | tx | both] [inpkts {enable | disable}]
[multicast {enable | disable}] [create]

If you are running a supervisor engine module software release prior to Release 4.5(1), configure only a single source port to be monitored. In supervisor engine module software Release 4.5(1) and later, a single source port is the standard Token Ring SPAN configuration.

After entering the set span command and specifying a source port and destination port, you see a display similar to the following:

 
Console> (enable) set span 3/2 3/6 tx

 
Enabled monitoring of Port 3/2 transmit traffic by Port 3/6

 
Console> (enable)

Enabling and Disabling SPAN

After configuring a SPAN port, ensure that SPAN is enabled on the switch. If SPAN is not enabled on the switch, you can enable it using the set span command.

To enable SPAN, issue the following command while in privileged mode:

: set span enable

To disable SPAN, issue the following command while in privileged mode:

: set span disable

Verifying the SPAN Configuration

To verify the SPAN configuration, issue the following command:

: show span

After entering the show span command, you see a display similar to the following:

 
Console> (enable) show span

 
Destination 	: Port 3/6

 
Admin Source	: Port 3/2

 
Oper Source	: Port 3/2

 
Direction	: transmit

 
Incoming Packets: disabled	

 
Multicast	: enabled

 
Console> (enable)

Table 10 describes the information returned by the show span command.

Table 10 Show span Command Field Descriptions

Field Description

Destination

Destination port to which the source port traffic is being copied.

Admin Source

Source port whose traffic is being monitored.

Oper Source

Source port or the ports within a TrCRF whose traffic is being monitored.

Direction

Indicates whether transmit, receive, or transmit/receive information is being monitored.

Incoming Packets

Status of whether reception of normal incoming packets on the SPAN destination port is enabled or disabled.

Multicast

Status of whether monitoring multicast traffic is enabled or disabled.

Configuring Filters

For network security, you can isolate parts of your network by limiting the scope and access of your users. To limit access, you can do the following:

Create a filter that blocks all data to a port except that which is explicitly allowed.
Define a filter that explicitly allows data from the select group of users (based on MAC address) to be sent to that port using MAC filters.

There are two types of filters that you can configure for the Catalyst 5000 series Token Ring module: protocol filters and MAC address filters. MAC address filters, based on MAC address (source address or destination address), can be configured for only input ports. Protocol (Destination Service Access Point [DSAP]/Subnetwork Access Protocol [SNAP]), filters can be configured for both input and output ports. You can configure up to 16 MAC address or DSAP/SNAP filters for each port on the Token Ring module.

Adding a MAC Address Filter

When configuring a MAC address filter, you can enter the MAC address in canonical or non-canonical format. You can also configure a MAC address filter as both a source or a destination for a specified port. Frames received that contain the MAC address specified as a source or destination address are dropped or passed, depending on whether you have specified for the filter to permit or deny the frames.

To add a filter based on MAC addresses, issue the following command in privileged mode:

: set port filter mod_num/port_num mac_addr {permit | deny | permit_ | permit_dst |
deny_src | deny_dst | deny_src_learn}

After entering the set port filter command, you see a display similar to the following:

 
Console> (enable) set port filter 3/2 00:40:0b:01:bc:65 permit

 
Port 3/2 filter Mac Address 00:40:0b:01:bc:65 set to permit.

 
Console> (enable)

Note You can define up to 16 MAC address filters per port to be filtered at the port of entry into the Catalyst 5000 series Token Ring module. MAC addresses can be unicast, multicast (group), or broadcast.

Adding a Protocol Filter

For a list of possible Ethertypes that you can specify, see the "Ethertypes" section. You can specify up to 16 DSAPs (in hexadecimal format) separated by spaces. For a list of possible service access points (SAPs), refer to the "Service Access Points" section.

To add a filter based on protocols, issue the following command in privileged mode:

: set port filter mod_num/port_num protocol_type {permit | deny}

After entering the set port filter command, you see a display similar to the following:

 
Console> (enable) set port filter 3/2 ip permit

 
Port 3/2 filter Protocol ip set to permit.

 
Console> (enable)

Note You can define up to 16 protocol filters (eight SAP and eight DSAP classes) per port to be filtered at the port of entry into the Catalyst 5000 series Token Ring module.

Clearing Filters

Using the clear port filter command, you can clear MAC address or protocol filters that have been configured on a specific port. You can also use the clear port filter command to clear all the filters configured for each of the ports on the Token Ring module.

To clear a MAC address filter, protocol filter, or all configured filters, issue the following command in privileged mode:

: clear port filter [mod_num/port_num] [mac_addr | protocol_type | all]

After entering the clear port filter command to clear a specific MAC address filter on a port, you see a display similar to the following:

 
Console> (enable) clear port filter 3/2 00:40:0b:01:bc:65

 
Port 3/2 filter Mac Address 00:40:0b:01:bc:65 cleared.

 
Console> (enable)

After entering the clear port filter command to clear all configured filters, you see a display similar to the following:

 
Console> (enable) clear port filter all

 
All filter MAC addresses and Protocols cleared

 
Console> (enable)

Verifying Filters

To verify the filters you have configured for the Token Ring module or for a specific port on the module, use the show port filter command.

To verify the filters configured on port 1 of module 3, issue the following command:

: show port filter 3/1

For MAC address filters, after entering the show port filter command, you see a display similar to the following:

 
Console> (enable) show port filter 3/1

 
Port  Mac-Addr          Type

 
----- ----------------- ------

 
 3/1  00:11:22:33:44:55 deny

 
Console> (enable)

For protocol filters, after entering the show port filter command, you see a display similar to the following:

 
Console> (enable) show port filter 3/1

 
Port  Mac-Addr          Type

 
----- ----------------- ------

 
 3/1  00:11:22:33:44:55 deny

 
Port  Protocol          Type

 
----- ----------------- ------

 
 3/1  0x6ff (ip)        permit

 
      0x800 (ip)        permit

 
      0x806 (ip)        permit

 
      0x8035(ip)        permit

Table 10 describes the information returned by the show port filter command issued with a module and port number specified.

Table 11 Show port filter Command Field Descriptions

Field	Description
Port	Module and port number.
MAC-Addr	MAC address contained in packets to be filtered.
Type	Type of MAC address filter configured.
Protocol	Types of protocols that you want to filter.
Type	Type of protocol filter configured. Possible types are deny (block any packet containing a specific protocol type) or permit (allow any packet containing a specific protocol type.)

Managing the Catalyst 5000 Series Token Ring Module

Use the following show commands to complete the listed tasks:

Task	Command
View module configuration and status.	show module [mod_num]
View port configuration and status.	show port [mod_num[/port_num]
View Token Ring configuration	show tokenring
View MAC counters.	show mac [mod_num[/port_num]]
View RIF information.	show rif
View port filters.	show port filter [mod_num[/port_num]
Display the error log for the system or module.	show log [mod_num]
View VLANs.	show vlan [vlan]
View STPs for a VLAN.	show spantree vlan
Display the error log for the system or module.	show log [mod_num]
Display MAC counters.	show mac
Display the results of diagnostic tests.	show test [mod_num]
Display the current state of a logical port.	show spantree portstate trcrf
View statistics and status information associated with each station on the ring.	show station controltable [mod_num[/port_num]
Display a list of the order of stations on the monitored rings.	show station ordertable [mod_num[/port_num]
View the soft error monitoring configuration on a port.	show station softerror config mod_num[/port_num]
Display soft error statistics for a station on a port.	show station softerror counters mod_num/port_num mac_address

Note For a description of the fields displayed in the output of the show commands listed above, see the "Catalyst 5000 Series Token Ring Module Command Reference" section.

Updating Software

As enhancements are made to the Catalyst 5000 series Token Ring module, you may need to update the software or microcode that is contained in the Catalyst 5000 series Token Ring module.

This section includes procedures for updating the software on the Catalyst 5000 series switch. New software to implement enhancements and maintenance releases will be provided periodically.

Perform the following steps to download software from a console using TFTP:

Step 1 Make sure the workstation acting as the download server has the TFTP daemon.

Step 2 On Sun workstations, make sure the /etc/inetd.conf file contains the following line:

 
     tftp dgram udp wait root /usr/etc/in.tftpd in.tftpd -p -s /tftpboot 

Make sure the /etc/services file contains the following line:

 
     tftp 69/udp 

Note You must restart the inetd daemon after modifying the /etc/inetd.conf and /etc/services files. To restart the daemon, either kill the inetd process and restart it, or issue a fastboot command (on the SunOS 4.x) or a reboot command (on Solaris 2.x or SunOS 5.x). Refer to your workstation manual for use of TFTP daemons.

Step 3 Copy the new software from the floppy disks to the home directory specified for the TFTP daemon on the workstation (usually /tftpboot). If this directory does not exist, create it before continuing. The file you copy is epsmain.dot1_0_xxx.bin, where xxx is the software revision number.

Step 4 Log in to the Catalyst 5000 through the administrative interface or through a Telnet session.

Step 5 Use the download command. Specify the IP address or host name of the workstation acting as the download server. Also specify the file to download and the number of the Token Ring module. The following is the command syntax:

download host filename [module num]

In the following example, the file is downloaded to module 3:

 
Console> (enable) download 190.180.122.40 filename.bin 3

Note If no module number is specified, the module to which the file is to be downloaded is automatically determined.

Step 6 When the following prompt appears, press y:

 
Download image filename from IP address to Module 3? (y/n) [n]? y 

Note The Token Ring module will be automatically reset after the image has been downloaded.

Step 7 Use the show version command to check the file you have just downloaded. If the version number is the correct number for the new software, the download was successful. If the version number is not the correct number, the download failed, and you must repeat the download procedure. Refer to the troubleshooting procedures below if the download failed.

Troubleshooting the TFTP Download Procedure

Follow the steps below for troubleshooting a failed serial download procedure:

Step 1 Make certain that the Catalyst 5000 has a route to the TFTP server, and use the ping command to test this connectivity.

Step 2 Make certain that the software image to be downloaded is in the correct directory.

Step 3 On the Catalyst 5000 series switch, make sure VTP V2 is enabled and at least one Token Ring port is active.

The network portion of the Catalyst 5000 IP address must be the same as the network portion of the TFTP server address. If the network download procedure fails because the power was interrupted during the download procedure, or for some other reason, the Flash code can become corrupted and the boot> prompt appears on the administration port. In that case, you can use the network download procedure to download the Flash code again through an enabled port in VLAN 1. By default, only port 1/1 is enabled. You can use port 1/1 or enable another port.

Understanding Token Ring Switching

This section contains the following information:

Switches versus Bridges and Routers
Bridging Modes
Dedicated Token Ring
Token Ring VLANs
STP

Switches versus Bridges and Routers

Because the number of stations that can be connected to any single ring is limited, large Token Ring LANs are divided into smaller rings. Furthermore, because stations must contend for the token with other stations on the same ring, attaching fewer stations to a ring gives each one a greater number of opportunities to transmit and receive information. This results in a larger number of rings, or segments.

The traditional method of connecting multiple Token Ring segments is to use a source-routing bridge. For example, bridges are often used to link workgroup rings to the backbone ring. However, the introduction of the bridge can significantly reduce performance at the user's workstation. Further problems may be introduced by aggregate traffic loading on the backbone ring.

To maintain performance and avoid overloading the backbone ring, you can locate servers on the same ring as the workgroup that needs to access the server. However, this makes the servers more difficult to back up, administer, and secure than if they are located on the backbone ring, and limits the number of servers that particular stations can access.

Collapsed backbone routers offer greater throughput than bridges, and can interconnect a larger number of rings without becoming overloaded. Routers provide both bridging and routing function between ring and have sophisticated broadcast control mechanisms. These mechanisms become increasingly important as the number of devices on the network increase.

The main drawback of using routers as the campus backbone is the relatively high price-per-port and the fact that the throughput typically does not increase as ports are added. A Token Ring switch is designed to provide wire speed throughput regardless of the number of ports in the switch. In addition, the switch can be configured to provide very low latency between Token Ring ports by using cut-through switching.

Bridging Modes

The Catalyst 5000 series Token Ring module supports the following bridging modes:

Source-Route Bridging (SRB)
Source-Route Transparent Bridging (SRT)
Source-Route Switching

Source-Route Bridging

SRB is the original method of bridging used to connect Token Ring segments. A source-route bridge makes all forwarding decisions based on data in the RIF. It does not learn or look up MAC addresses. Therefore, SRB frames without a RIF are not forwarded.

Clients or servers that support source routing typically send an explorer frame to determine the path to a given destination. There are two types of explorer frames: ARE and spanning-tree explorer. All SRB bridges copy ARE frames and add their own routing information. For frames that are received from or sent to ports that are in the spanning-tree forwarding state, bridges copy spanning-tree explorer frames and add their own routing information. Because ARE frames will traverse all paths between two devices, they are used in path determination. Spanning-tree explorer frames are used to send datagrams because the spanning tree will ensure that only one copy of an spanning-tree explorer frame is sent to each ring.

Note The spanning tree used with source-routing is different from the IEEE spanning tree used in transparent bridges. The Catalyst 5000 series Token Ring module supports both types of spanning-tree algorithms.

Source-Route Transparent Bridging

SRT bridging is an IEEE standard that combines source-route bridging and transparent bridging. An SRT bridge forwards frames that do not contain a RIF based on the destination MAC address. Frames that contain a RIF are forwarded based upon source-routing. The SRT bridge only runs the IEEE STP. It does not support the IBM Spanning Tree Protocol.

Source-Route Switching

Similar to a transparent bridge, the Catalyst 5000 series Token Ring module can forward broadcast, multicast, and unicast frames based on MAC address. If, however, you have source-route bridges in your network, the Token Ring module can forward frames based on the RIF. This dual frame-forwarding technology is called source-route switching.

In source-route switching, the switch learns and forwards frames based on source-route descriptors for stations that are one or more source-route bridge hops away. A route descriptor is a portion of a RIF that indicates a single hop. It is defined as a ring number and a bridge number. When a source-routed frame enters the switch, the switch learns the route descriptor for the hop closest to the switch. Frames received from other ports with the same next-hop route descriptor as their destination will be forwarded to that port.

The key difference between SRB and source-route switching is that while a source-route switch looks at the RIF, it never updates the RIF. Therefore, all ports in a source-route switch group have the same ring number.

Source-route switching provides the following benefits:

The switch does not need to learn the MAC addresses of the devices on the other side of a source-route bridge. Therefore, the number of MAC addresses that the switch must learn and maintain is significantly reduced.
The switch can support parallel source-routing paths.
An existing ring can be partitioned into several segments without requiring a change in the existing ring numbers or the source-route bridges.
The switch can support duplicate MAC addresses if the stations reside on LAN segments with different LAN IDs (ring numbers).

Dedicated Token Ring

Classic 4- and 16-Mbps Token Ring adapters must be connected to a port on a concentrator. These adapters are also limited to operating in half-duplex mode. In half-duplex mode, the adapter can only be sending or receiving a frame; it cannot do both simultaneously.

Dedicated Token Ring, developed by the IEEE, defines a method in which the switch port can emulate a concentrator port, thereby eliminating the need for an intermediate concentrator. In addition, dedicated Token Ring defines a new full-duplex data passing mode called Transmit Immediate, which eliminates the need for a token and allows the adapter to transmit and receive simultaneously.

Dedicated Token Ring is particularly useful for providing improved access to servers. A server can be attached directly to a switch. This allows the server to take advantage of the full 16 Mbps available for sending and receiving and results in an aggregate bandwidth of 32 Mbps.

Token Ring VLANs

Within a Token Ring VLAN, logical rings can be formed by defining groups of ports that have the same ring number. The IEEE calls such a port group a Token Ring Concentrator Relay Function (TrCRF). In general, a TrCRF is limited to the ports in a single Token Ring module on the Catalyst 5000 series switch. However, there is one exception to this rule that is discussed in the "Adding or Changing TrCRF Parameters" section.

Within the TrCRF, source-route switching is used for forwarding based on either MAC addresses or route descriptors. If desired, the entire VLAN can operate as a single ring. Frames can be switched between ports within a single TrCRF.

Figure 14 Token Ring VLANs

As shown in Figure 14, multiple TrCRFs can be interconnected using a single Token Ring Bridge Relay Function (TrBRF). For source routing, the switch appears as a single bridge between the logical rings. The TrBRF can function as an SRB or SRT bridge running either the IBM or IEEE STP. If SRB is used, duplicate MAC addresses can be defined on different logical rings.

To accommodate SNA traffic, you can use a combination of SRT and SRB modes. In a mixed mode the TrBRF considers some ports (logical ports connected to TrCRFs) to be operating in SRB mode while others are operating in SRT mode.

The TrBRF can be extended across a network of switches via high-speed uplinks between the switches. These links must have the ability to multiplex multiple VLANs and provide the necessary information to support logical rings.

STP

The STP is a broadcast algorithm used by network bridge connections to dynamically discover a loop-free subset of the network topology while maintaining a path between every pair of LANs or VLANs in the network.

To accomplish this, the STP blocks ports that, if active, would create bridging loops. If the primary link fails, it activates one of the blocked bridge ports to provide a new path through the network.

In a traditional bridged network, there is one STP for each bridge connection. Each bridge maintains its own database of configuration information and transmits and receives only on those ports belonging to the bridge. The type of STP that runs on a bridge depends on the transmission mode of the bridge connection (whether the connection is transparent, SRB, source-source route switched, or SRT).

In a switched network, you can configure virtual networks. A switch can have ports that belong to different VLANs, some of which may span several switches.

As discussed in the "Virtual LAN Support" section, in a Token Ring switch, there are two levels of VLANs. The grouping of ports (TrCRFs) is connected by logical bridges (TrBRFs).

Therefore, in a Token Ring switched network, to ensure loops are removed from the topology you must configure a separate STP for each logical bridge (TrBRF) and for each of the port groupings (TrCRF) configured for a VLAN.

How the STP Algorithm Works

The following is a general summary of how the STP eliminates loops in the network:

1. Each bridge is assigned an 8-byte unique bridge identifier.

The first 2 bytes are a priority field, and the last 6 bytes contain one of the bridge's MAC addresses. The bridge with the lowest bridge identifier among all bridges on all LAN segments is the root bridge. The network administrator can assign a lower bridge priority to a selected bridge to control which bridge becomes the root, or the administrator can use default bridge priorities and allow the STP to determine the root.

2. Each bridge port is associated with a path cost.

The path cost represents the cost of transmitting a frame to a bridged segment through that port. A network administrator typically configures a cost for each port based on the speed of link (for example, the cost of a port connected to a 16-Mbps LAN could be assigned a lower path cost than a port connected to a 4-Mbps LAN).

3. Each bridge determines its root port and root path cost.

The root port is the port that represents the shortest path from itself to the root bridge. The root path cost is the total cost to the root.

All ports on the root bridge have a zero cost.

4. All participating bridges elect a designated bridge from among the bridges on that LAN segment.

A designated bridge is the bridge on each LAN segment that provides the minimum root path cost. Only the designated bridge is allowed to forward frames to and from that LAN segment toward the root.

5. All participating bridges select ports for inclusion in the spanning tree.

The selected ports will be the root port plus the designated ports for the designated bridge. Designated ports are those where the designated bridge has the best path to reach the root. In cases where two or more bridges have the same root path cost, the bridge with the lowest bridge identifier becomes the designated bridge.

6. Using the preceding steps, all but one of the bridges directly connected to each LAN segment are eliminated, thereby removing all multiple LAN loops.

How Spanning-Tree Information is Shared

The STP calculation requires that bridges communicate with other bridges in the network that are running the STP. Each bridge is responsible for sending and receiving configuration messages called bridge protocol data units (BPDUs).

BPDUs are exchanged between neighboring bridges at regular intervals (typically 1 to 4 seconds) and contain configuration information that identifies the:

Bridge that is presumed to be the main bridge or root (root identifier)
Distance from the sending bridge to the root bridge (called the root path cost)
Bridge and port identifier of the sending bridge
Age of the information contained in the configuration message

If a bridge fails and stops sending BPDUs, the bridges detect the lack of configuration messages and initiate a spanning-tree recalculation.

BPDU Field Formats

Figure 15 shows the format of the fields inside a BPDU.

Note All fields in the BPDU are common to all STPs except for the Port ID field. If the BPDU is an IEEE or Cisco STP BPDU message, the Port ID field specifies the transmitting port number of the originating bridge. If the BPDU is an IBM STP BPDU message, then the Port ID field specifies the ring and bridge number through which the message was sent.

2	1	1	1	8	4	8	2	2	2	2	2
Protocol Identifier	Version	Message Type	Flags	Root ID	Root Path Cost	Bridge ID	Port ID	Message Age	Max Age	Hello Time	Forward Delay

Figure 15 BPDU Field Formats

2 1 1 1 8 4 8 2 2 2 2 2

Protocol Identifier

Version

Message Type

Flags

Root ID

Root Path Cost

Bridge ID

Port ID

Message Age

Max Age

Hello Time

Forward Delay

Table 12 BPDU Configuration Message Fields

Protocol Identifier

Identifies the protocol. This field contains the value zero.

Version

Identifies the version. This field contains the value zero.

Message Type

Identifies the message type. This field contains the value zero.

Flags

1-byte field, of which only the first two bits are used. The topology change (TC) bit signals a topology change. The topology change acknowledgment (TCA) bit is set to acknowledge receipt of a configuration message with the TC bit set. This field is not valid for IBM STP BPDUs.

Root ID

Identifies the root bridge by listing its 2-byte priority followed by its 6-byte ID.

Root Path Cost

Cost of the path from the bridge sending the configuration message to the root bridge.

Bridge ID

Priority and ID of the bridge sending the message.

Port ID

Port number (IEEE or Cisco STP BPDU) or the ring and bridge number (IBM STP BPDU) from which the configuration message was sent. This field allows loops created by multiple attached bridges to be detected and corrected.

Message Age

Indicates the amount of time that has elapsed since the root sent the configuration message on which the current configuration message is based.

Max Age

Indicates when the current configuration message should be deleted.

Hello Time

Indicates the time between root bridge configuration messages.

Forward Delay

Indicates the length of time that bridges should wait before transitioning to a new state after a topology change. If a bridge transitions too soon, it is possible that not all network links will be ready to change their state and loops can result.

Catalyst 5000 Series Token Ring Module Spanning-Tree Support

The Catalyst 5000 series Token Ring module supports the following STPs:

IEEE 802.1d
IBM
Cisco

The Catalyst 5000 series switch uses the IEEE 802.1d and IBM STPs on TrBRFs. The STP running on the TrCRF is either the Cisco or IEEE STP, depending upon the STP being run on the TrBRF and the bridging mode configured for the TrCRF using the set vlan command. The default configuration has all STPs enabled.

Table 13 lists the STP activity at the TrBRF and TrCRF levels depending upon the TrBRF STP and the TrCRF bridge mode configuration.

Table 13

TrBRF STP Setting TrCRF Bridge Mode / ISL Port Setting TrBRF STP TrCRF STPF

IBM

SRB
SRT
ISL Ports

IBM
None¹
IBM

IEEE
Cisco
None

IEEE

SRB
SRT
ISL Ports

None ¹
IEEE
IEEE

IEEE
Cisco
None

1 Logical ports of the TrBRF may be set to forwarding state using the set spantree portstate command.

TrBRF STP Setting	TrCRF Bridge Mode / ISL Port Setting	TrBRF STP	TrCRF STPF
IBM	SRB SRT ISL Ports	IBM None¹ IBM	IEEE Cisco None
IEEE	SRB SRT ISL Ports	None ¹ IEEE IEEE	IEEE Cisco None

TrBRF and TrCRF STPs

The following sections briefly describe the type of transmission mode supported by each STP.

IEEE 802.1d STP

The IEEE STP can be used at the TrCRF or the TrBRF level. This type of spanning tree supports bridge domains and allows the bridge to construct a loop-free topology across an extended LAN. Specifically, the IEEE 802.1d STP supports the following bridge modes:

Transparent Bridging
Source-Route Switching
Source-Route Transparent Bridging

The IEEE 802.1d STP BPDU format is:

Destination Address

Source Address

SAP

BPDU

Transparent Bridging

When a bridge connection is transparent mode:

The bridge connection learns the source MAC addresses.
Frames are forwarded based upon the destination address.

Source-Route Switching

When a bridge connection is source-route switching:

The bridge connection learns route descriptors for frames that contain a RIF and learns the source MAC addresses for frames that do not contain a RIF.
Source-route frames are forwarded based on the route descriptor.
Non-source-route frames are forwarded based on the destination address.

Source-Route Transparent Bridging

When a bridge connection is source-route transparent:

Transparent bridging and source-route bridging modes are combined.
The bridge connection learns route descriptors for frames that contain a RIF and learns the source MAC addresses for frames that do not contain a RIF.
Non-source-route frames are forwarded based on the destination address.
Source-route frames are forwarded based on the route descriptor.
ARE and spanning-tree explorer frames are issued and forwarded.
The IEEE STP is used to eliminate loops for non-source-route and spanning-tree explorer frames.

IBM STP

The IBM STP can be used at the TrBRF level. This type of spanning tree was developed to maintain the path for source-route broadcast traffic.

Source-Route Bridging

When a bridge connection is source-route:

The bridge connection learns the source MAC address for frames that originate from the local ring and the route descriptor for frames that originate on the other side of a source-route bridge.
Non-source-route frames are not forwarded.
Source-route frames are forwarded based on the route descriptor.
ARE and spanning-tree explorer frames are issued and forwarded.
The IBM STP is used to eliminate loops only for spanning-tree explorer frames.

The IBM STP BPDU format is:

Destination Address

Source Address

SAP

BPDU

Cisco STP

The Cisco STP was designed for use at the TrCRF level. This type of spanning tree was developed to address a looping problem that can be introduced when you use VLANs in a Token Ring environment.

One of the rules in processing source-route traffic is that a source-route frame should never be forwarded to a ring that it has previously traversed. If the RIF of a source-route frame already contains the ring number for the next hop, the bridge assumes that the frame has already been on that ring and drops the frame.

With Token Ring VLANs, however, this rule can cause a problem. With the existing STP, a frame that originated on one physical ring of a Token Ring VLAN and is processed by an external SRT bridge would not be forwarded to another physical ring of the same Token Ring VLAN. Therefore, the IEEE 802.1d STP was used as a basis to create the Cisco STP. The Cisco STP ensures that traffic from one physical ring of a VLAN is not blocked from the other physical rings that comprise the VLAN.

Table 14 summarizes the activities occurring in the TrCRF and TrBRF when the Cisco STP is run.

Table 14 Cisco STP and Bridging Modes

TrCRF Bridging Mode TrCRF TrBRF

SRB

Runs the IEEE STP.

Processes IBM STP BPDUs from external bridges.

Performs as a source-route bridge.

Runs the IBM STP to external bridges.

Drops transparent IEEE STP BPDUs of the TrCRF.

SRT

Runs the Cisco STP.

Replaces bridge group address of destination address field with a Cisco-specific group address to prevent external bridges from analyzing TrCRF BPDUs.

Generates BPDUs with the Routing Information Identifier bit in the source address field set in the outbound frame and a 2-byte RIF added.

This frame format ensures that the TrCRF remains local to the logical ring and is not transparently bridged or source routed to other LANs. Only TrCRFs connected via physical loops receive the BPDUs.

Processes IEEE STP BPDUs from external bridges.

Performs as a source-route transparent bridge.

Forwards transparent and source-route traffic.

Forwards source-route traffic to all other TrCRFs in the TrBRF whether they be in SRT or SRB mode.

The Cisco STP BPDU format is:

Destination Address

Source Address

RIF

SAP

BPDU

Spanning-Tree BPDU Formats Summary

For each BPDU format:

The destination address is specified in the bridge group address table.
The source address is the base MAC address used by the switch.
The SAP field should be set to 0x424203.

For the Cisco STP BPDU format, the source address must have the "msp masked" on to indicate the presence of a RIF in the header. The information carried in the RIF for the Cisco STP BPDU is a 2-byte field and must be set to 0x0200.

Catalyst 5000 Series Token Ring Module Command Reference

This section lists and describes commands specific to the Catalyst 5000 series Token Ring module as well as existing Catalyst 5000 series switch commands that have been altered for the Catalyst 5000 series Token Ring module. For a complete description of all the Catalyst 5000 series commands, refer to the Catalyst 5000 Series Command Reference.

clear port filter

Use the clear port filter privileged command to clear MAC address or protocol filters, filters configured on a specific port, or to clear all filters that have been configured.

: clear port filter [mod_num/port_num] {mac_addr | protocol_type | all}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
mac_address	MAC address contained in the packets to be filtered. This address can be entered in canonical format (00-11-33-44-55) or in non-canonical (00:11:22:33:44:55) format.
protocol_type	Type of protocol to be filtered.
all	Keyword used to specify for all filters to be cleared.

Default

The command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Up to 16 MAC address filters or 16 protocol (eight SAP and eight DSAP) filters can be configured per port on the Token Ring module.

Example

The following example shows clearing a MAC address filter (00:40:0b:01:bc:65) configured on port 2 of module 3:

 
Console> (enable) clear port filter 3/2 00:40:0b:01:bc:65

 
Port 3/2 filter Mac Address 00:40:0b:01:bc:65 cleared.

 
Console> (enable)

Related Commands

set port filter
show port filter

clear station

Use the clear station privileged command to issue a Remove Ring Station MAC frame to remove a station from the ring.

: clear station mod_num/port_num mac_addr

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
mac_address	MAC address of the station that you want to remove. Enter this address in non-canonical (00:11:22:33:44:55) format.

Default

The command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Example

The following example shows a station with the MAC address 00:40:0b:01:bc:65 on port 2 of module 3 being removed:

 
Console> (enable) clear station 3/2 00:40:0b:01:bc:65

 
Mac Address 00:40:0b:01:bc:65 cleared.

 
Console> (enable)

Related Commands

set station softerror
show station softerror config
show station softerror counters

clear station counters

Use the clear station counters privileged command to reset the soft error statistics that display when you issue the show station softerror counters command. You can clear statistics collected for a station on a port, the module, or for a specific port on the module.

: clear station counters mod_num[/port_num]

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.

Default

The command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Example

The following example shows the soft error statistics collected for stations on port 10 of module 3 being reset:

 
Console> (enable) clear station counters 3/10

 
Port 3/10 station counters cleared.

Related Commands

set station softerror
show station softerror counters

set port filter

Use the set port filter privileged command to configure a MAC address filter or a protocol filter for ports on your Token Ring module.

: set port filter mod_num/port_num {mac_addr | protocol_type} {permit | deny | permit_ |
permit_dst | deny_src | deny_dst | deny_src_learn}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
mac_address	MAC address contained in the packets to be filtered. This address can be entered in canonical format (00-11-33-44-55) or in non-canonical (00:11:22:33:44:55) format.
protocol_type	Protocol type that you want to filter. For a list of the protocol types that you can filter, see the "Codes" section.
permit	Keyword used to specify that the filter can permit packets with the specified MAC address or protocol type.
deny	Keyword used to specify that the filter can deny packets with the specified MAC address or protocol type.
permit_	Keyword used to specify to allow any packet with the specified MAC address as the source address.
permit_dst	Keyword used to specify to allow any packet with the specified MAC address as the destination address.
deny_	Keyword used to specify to block any packet with the specified MAC address as the source address.
deny_dst	Keyword used to specify to block any packet with the specified MAC address as the destination address.
deny__learn	Keyword used to specify that the Token Ring module is not to learn the specified MAC address as a source address.

Default

The command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Up to 16 MAC address filters or 16 protocol (eight SAP and eight DSAP) filters can be configured per port on the Token Ring module.

Example

The following example shows configuring a port filter on port 2 MAC address 00:40:0b:01:65) of module 3:

 
Console> (enable) set port filter 3/2 00:40:0b:01:bc:65 permit

 
Port 3/2 filter Mac Address 00:40:0b:01:bc:65 set to permit.

 
Console> (enable)

Related Commands

clear port filter
show port filter

set port speed

Use the set port speed privileged command to configure the speed of a port interface. You can configure the speed of a Fast Ethernet interface and a Token Ring interface.

: set port speed mod_num/port_num {4 | 10 | 16 | 100 | auto}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
4 \| 10 \| 16 \| 100 \| auto	Keyword used to set a port speed to 4, 10, 16, 100 Mbps, or auto speed detection mode. The default is auto. Port speeds 4 and 16 Mbps apply only to Token Ring ports. Port speeds 10 and 100 Mbps apply only to Ethernet ports.

Default

The default configuration has all Token Ring module ports set to auto.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Token Ring interfaces on the Token Ring module can be configured to either 4 Mbps or 16 Mbps. They can also be set to auto speed detection mode, allowing them to sense and distinguish between 4-Mbps and 16-Mbps port transmission speed. Set at auto speed detection mode, the interfaces automatically configure themselves to operate at the proper speed.

If you change the transmission speed of a port that is open to 4 or 16 Mbps, the port will close and reopen at the new transmission speed. If a port closes and reopens on an existing ring using a transmission speed different from that which the ring is operating, the ring will beacon.

If the ports on the Token Ring module are configured to automatically sense the speed of the ring, the first port inserted on the ring will not set the speed, for it will be unable to detect the speed.

Example

The following example shows how to set ports 2, 3, and 4 on module 3 to 16 Mbps, 4 Mbps, and auto speed detection mode:

 
Console> (enable) set port speed

 
Usage: set port speed <mod_num/port_num> <4|10|16|100|auto>

 
Console> (enable) set port speed 3/4 16

 
Port(s) 3/4 speed set to 16Mbps.

 
Console> (enable) set port speed 3/4 auto

 
Port(s) 3/4 speed set to auto detect.

Related Commands

set port disable
set port enable
set port help
set port name
set port trap
set tokenring portmode
set tokenring priority
show port

set span

Use the set span command to enable or disable SPAN and to set up the switch port and VLAN analyzer for multiple SPAN sessions.

: set span disable [dest_mod/dest_port | all]
: set span {_mod/src_ports... | src_vlan... | sc0} {dest_mod/dest_port} [rx | tx | both]
[inpkts {enable | disable}] [multicast {enable | disable}] [create]

Syntax Description

disable	Keyword to disable SPAN.
dest_mod	Monitoring module (SPAN destination).
dest_port	Monitoring port (SPAN destination).
_mod	Monitored module (SPAN source).
_ports...	Monitored ports (SPAN source).
_vlan...	Monitored VLAN (SPAN source).
sc0	Keyword to specify the in-band interface.
rx	(Optional) Keyword to specify that information received at the source is monitored.
tx	(Optional) Keyword to specify that information transmitted from the source is monitored.
both	(Optional) Keyword to specify that information both transmitted from the source and received at the source is monitored.
inpkts enable	(Optional) Keywords to enable the receiving of normal inbound traffic on the SPAN destination port.
inpkts disable	(Optional) Keywords to disable the receiving of normal inbound traffic on the SPAN destination port.
multicast enable	(Optional) Keywords to enable the receiving multicast packets on the SPAN destination port.
multicast disable	(Optional) Keywords to disable the receiving multicast packets on the SPAN destination port.
create	(Optional) Keyword to create a new SPAN session.

Default

The default has no SPAN configured.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

You can configure multiple SPAN sessions to run at the same time. One ingress span session (RX or Both direction) and four egress span sessions (TX direction only) can be configured.

A trunk port can be configured as a source or destination port. If the destination port is a trunk port, the outgoing packets through the SPAN port will carry ISL or 802.1Q VLAN headers.

If SPAN is enabled, and you change the VLAN configuration of the SPAN port (destination), you must disable SPAN before the new configuration will be in effect.

If SPAN is enabled, and you disable a source or destination port, the SPAN function will not work until you enable SPAN on both ports.

You can configure a disabled port to be a source or destination port, but the SPAN function will not work until you enable SPAN on both ports.

If SPAN is enabled for monitoring a particular VLAN, the number of ports being monitored changes when you move a switched port into or out of the specified monitored VLAN.

FDDI port can also be a source port.

Source and destination ports can not be the same port.

After SPAN is enabled, if no parameters were ever set, the first configured SPAN is used as a reference.

You can configure additional SPAN ports which monitor VLANs only. These ports support a source of one or more VLANs and require the destination port to be a trunk-capable port. This port will filter all traffic except traffic from the configured VLAN for that port.

For monitoring inbound traffic, only one ingress session (or both direction) SPAN is allowed regardless of the port-based SPAN. An egress SPAN can coexist with other SPAN sessions.

Use either a dedicated RMON probe (such as the Catalyst 5000 series Network Analysis Module) or a network analyzer to monitor ports.

Use the inpkts keyword with the enable option to allow the SPAN destination port to receive normal incoming traffic in addition to the traffic mirrored from the SPAN source. Use the disable option to prevent the SPAN destination port from receiving normal incoming traffic.

You can specify an RSM port as the SPAN source port. However, you cannot specify an RSM port as the SPAN destination port.

The source and destination ports have to be within the module.

If you are configuring SPAN on the Catalyst 5000 and 2926G series Gigabit EtherChannel switching module, the source and destination ports must be on the same module. This restriction does not apply to the following:

Three-port Gigabit Ethernet module (WS-X5403)
Catalyst 4000 and 2948G series switch modules

If you are configuring the Gigabit EtherChannel switching module VLAN, only the both argument is allowed, you cannot specify tx or rx.

Catalyst 4000 and 2948G series switches do not support the sc0 keyword.

Catalyst 4000 and 2948G series switches do not permit you to disable multicast on SPAN ports.

The Token Ring port can be a source or destination port. When monitoring the tx direction, only one source port is allowed, and the Token Ring module does not support the inpkts option. A Token Ring port can only monitor another Token Ring port.

If you are running a supervisor engine software release prior to release 4.5(1), configure only a single source port to be monitored. With the supervisor engine software release 4.5(1) and later, a single source port will be the standard Token Ring SPAN configuration.

You cannot monitor a VLAN to which none of the ports belong.

Examples

This example shows how to configure SPAN so that the transmit traffic on the source port (3/2) is mirrored to the destination port (3/6), and how to verify SPAN configuration:

 
Console> (enable) set span 3/2 3/6 tx

 
Enabled monitoring of Port 3/2 transmit traffic by Port 3/6

 
Console> (enable)

 
Console> (enable) show span

 
Status      : enabled

 
Admin Source: Port 3/2

 
Oper Source : Port 3/2

 
Destination : Port 3/6

 
Direction   : transmit

 
Console> (enable)

set spantree help

Use the set spantree help privileged command to list the available set spantree commands.

: set spantree help

Syntax Description

This command has no arguments or keywords.

Default

This command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Example

The following example shows how to list the set spantree commands:

 
Console> (enable) set spantree

 
Set spantree commands:

 
----------------------------------------------------------------------

 
set spantree disable       	Disable spanning tree

 
set spantree enable        	Enable spanning tree

 
set spantree fwddelay     	Set spantree forward delay

 
set spantree hello         	Set spantree hello interval

 
set spantree help         	Show this message

 
set spantree maxage        	Set spantree max aging time

 
set spantree multicast-address 	Set the spantree functional address

 
set spantree portcost      	Set spantree port cost

 
set spantree portfast      	Set spantree port fast start

 
set spantree portpri       	Set spantree port priority

 
set spantree portstate     	Set spantree logical port state

 
set spantree portvlancost  	Set spantree port cost per vlan

 
set spantree portvlanpri   	Set spantree port vlan priority

 
set spantree priority      	Set spantree priority

 
set spantree root          	Set switch as primary or secondary root

 
set spantree uplinkfast   	Enable or disable uplinkfast groups

 
Console> (enable)

set spantree multicast-address

Use the set spantree multicast-address command to specify for a TrBRF to use the IBM bridge functional address or the IEEE Spanning Tree Protocol address.

: set spantree multicast-address vlan_num {ieee | ibm}

Syntax Description

vlan_num	Number of the TrBRF for which you are setting the address.
ieee	Keyword used to specify for the IEEE STP address to be used.
ibm	Keyword used to specify for the IBM bridge functional address to be used.

Default

The default configuration has IEEE.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

This command applies only to a TrBRF that is running IEEE STP.

Example

The following example shows specifying for the bridge functional address to be used:

 
Console> (enable) set spantree multicast-address ibm 100

Related Commands

show spantree

set spantree portcost

Use the set spantree portcost privileged command to set the path cost for a physical port or logical port (the connection between a TrCRF and TrBRF).

: set spantree portcost {mod_num/port_num | trcrf} cost

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
trcrf	Number of the TrCRF for which you are setting the path cost.
cost	Number from 1 to 65535 that indicates the cost of the path. 1 is a low cost and 65535 is a high cost.

Default

The default configuration is as follows:

100BaseTX Ethernet port cost = 10
10BaseT Ethernet port cost = 100
FDDI port cost = 10
ATM port cost = 6
Token Ring port cost = 62

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

The STP uses port path costs to determine which port to select as a forwarding port. Therefore, lower numbers should be assigned to ports attached to faster media (such as full duplex) and higher numbers should be assigned to ports attached to slower media. The possible range is 1 to 65535. The default for the Token Ring module ports is 62. The recommended path cost is 1000/LAN speed in Mbps.

Example

The following example shows how to set the port cost for port 4 on module 3 to 16 Mbps:

 
Console> (enable) set port speed 3/4 16

 
Port(s) 3/4 speed set to 16Mbps.

 
Console> (enable)

Related Commands

show spantree

set spantree portpri

Use the set spantree portpri privileged command to set the bridge priority for a spanning-tree port or TrCRF.

: set spantree portpri {mod_num/port_num | trcrf} priority

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
trcrf	Number identifying the TrCRF for which you are setting the bridge priority.
priority	Number that represents the cost of a link in a spanning-tree bridge. For physical Token Ring ports, the possible priority range ins 0 through 255 (decimal). The default is 128. For logical ports, the possible priority range is 0 through 7. The default is 4.

Default

The default configuration has all physical Token Ring ports with bridge priority set to 128. Logical ports are set to 4 by default.

Command Type

Switch command

Command Mode

Privileged

Usage Guideline

The specified bridge priority on an ATM port applies to all emulated LANs on that port.

Example

The following example shows how to set the priority of port 1 on module 4 to 63:

 
Console> (enable) set spantree portpri 4/1 63

 
Bridge port 4/1 priority set to 63.

 
Console> (enable)

Related Commands

show spantree

set spantree portstate

Use the set spantree portstate privileged command to manually set the state of a logical port (the connection between a TrCRF and TrBRF).

: set spantree portstate trcrf {block | forward | auto} [trbrf]

Syntax Description

trcrf	Number of the TrCRF.
block \| forward \| auto	Keywords used to set the logical port to a blocked state (block), forwarding state (forward) or to have the correct state automatically determined by the STP (auto).
trbrf	Number of the parent TrBRF.

Default

There is no default configuration for this command.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

This command can only be used to set the port state when the TrCRF is in SRT mode and the TrBRF is running the IBM STP, or, the TrCRF is in SRB mode and the TrBRF is running the IEEE STP.

When STP is enabled, every switch in the network goes through the blocking state and the transitory states at power up. The ports then stabilize to the forwarding or blocking state. With TrBRFs and TrCRFs, there are two exceptions to this rule that require you to manually set the state of the logical ports of a TrBRF. The two exceptions are if:

The TrBRF is running the IBM STP and the TrCRF is in SRT mode.
The TrBRF is running the IEEE STP and the TrCRF is in SRB mode.

Example

The following example shows the manual setting of TrCRF 900 to a forwarding state:

 
Console> (enable) set spantree portstate 900 forward

 
Console> (enable)

Related Commands

show spantree

set station softerror

Use the set station softerror privileged command to enable or disable the collection of soft error statistics on the ports on a Token Ring module or on a specific port on the module. Also, use the set station softerror command to define error thresholds and sampling intervals for the ports on the Token Ring module or for a specific port on the module.

: set station softerror mod_num[/port_num] disable | enable [threshold thres_num
interval int_num]

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
disable	Keyword used to specify for soft error statistics to not be collected for the stations on a module or on a specific port on a module.
enable	Keyword used to specify for soft error statistics to be collected for the stations on a module or on a specific port on a module.
threshold thres_num	Keyword used to specify the number of soft errors reported from a station connected to a port that if exceeded causes a soft error exceeded trap to be issued. Valid values are 1 to 255. The default is 100.
interval int_num	Keyword used to specify the sampling period (in seconds) during which the number of soft errors is monitored for each station connected to a port. Valid values are 0 to 65534. The default is 60. To disable soft error exceeded traps, set the interval to zero. Without traps, soft errors can still be monitored via the console.

Default

The default configuration has soft error monitoring disabled. The default error threshold is 100. The default interval is 60.

Command Type

Switch command

Command Mode

Privileged

Example

The following example shows how to enable the collection of soft error statistics for port 10 on module 3:

 
Console> (enable) set station softerror 3/10 enable

 
Port 3/10 soft error monitoring enabled.

 
Console> (enable)

The following example shows the error threshold and sampling interval for port 10 on module 3 being set:

 
Console> (enable) set station softerror 3/10 threshold 100 interval 200

 
Port 3/10 station soft error threshold set to 100, interval set to 200

 
Console> (enable)

Related Commands

clear station counters
show station softerror config
show station softerror counters

set tokenring acbits

Use the set tokenring acbits privileged command to specify whether AC bits shall be set unconditionally when a port forwards certain LLC frames.

: set tokenring acbits mod_num/port_num {enable | disable | sronly | never | always}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
enable	Keyword used to unconditionally set the AC bits on source-routed frames with a RIF length greater than 2 and on all explorer frames in addition to setting the AC bits on all frames forwarded to another port. This parameter is only valid when local address learning is enabled on a port. Therefore, specifying enable automatically enables local address learning on the port.
disable	Keyword used to specify for the AC bits to be set based exclusively on whether the frame is forwarded to another port. This parameter is only valid when local address learning is enabled on a port. Therefore, specifying disable automatically enables local address learning on the port.
sronly	Keyword used to specify for the AC bits to be set only on source-routed frames with a RIF length greater than 2 and on all explorer frames.
never	Keyword used to specify for the AC bits to never be set on LLC frames. This parameter is only valid when local address learning is disabled on the port. Therefore, specifying never automatically disables local address learning on the port.
always	Keyword used to specify for the AC bits to always be set on LLC frames. This parameter is only valid when local address learning is disabled on a port. Therefore, specifying always automatically disables local address learning on the port.

Default

The default configuration is disable.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Using the set tokenring actbits command, you can specify if and how the AC bits should be set on LLC frames. When local address learning is enabled on a Token Ring port, the default is disable. When local address learning is disabled on a Token Ring port, the default is always.

Example

The following examples show port 4 on module 4 being enabled to unconditionally set the AC bits when forwarding certain LLC frames and then being disabled.

 
Console> (enable) set tokenring acbits 4/4 enable

 
Port 4/4 acbits enabled.

 
Console> (enable) set tokenring acbits 4/4 disable

 
Port 4/4 acbits disabled.

Related Commands

set tokenring locallearning
set tokenring portaging
show tokenring

set tokenring configloss

Use the set tokenring configloss privileged command to specify thresholds that, when exceeded during the user-specified interval, will cause the port to be administratively disabled.

: set tokenring configloss mod_num/port_num [threshold thresh_num] [interval int_num]

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
threshold thresh_num	Keyword to set the threshold for configuration losses. Valid values are 1 to 100. The default is 8.
interval interval_num	Keyword to set the interval at which the configuration loss is measured. Valid values are 1 to 99 minutes. The default is 10.

Default

The default threshold configuration is 8. The default interval is 10.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Example

The following shows how to set a configuration loss threshold of 25 and an interval of 5 minutes for port 1 on module 4.

 
Console> (enable) set tokenring configloss 4/1 threshold 25 interval 5

 
Port 4/1 configloss threshold set to 25, interval set to 5.

 
Console> (enable)

Related Commands

show tokenring

set tokenring distrib-crf

Use the set tokenring distrib-crf command to enable or disable the ability to configure a distributed TrCRF.

: set tokenring distrib-crf {enable | disable}

Syntax Description

enable	Keyword to enable the ability to configure distributed TrCRFs.
disable	Keyword to disable the ability to configure distributed TrCRFs.

Default

The default is for the ability to configure a distributed TrCRF to be disabled.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Use extreme caution when configuring a distributed TrCRF in your network. Ensure that no loops are configured in the network before configuring a distributed TrCRF.

Example

The following example shows how to enable the ability to configure a distributed TrCRF:

 
Console> (enable) set tokenring distrib-crf enable

 
WARNING:Ports will NOT be inactivated for distributed crfs. NETWORK LOOPS MAY OCCUR.

 
Console> (enable)

Related Commands

show tokenring

set tokenring etr

Use the set tokenring etr privileged command to enable or disable a Token Ring port's use of the Early Token Release procedure when transmitting frames.

: set tokenring etr mod_num/port_num {enable | disable}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
enable \| disable	Keyword used to specify that Early Token Release should be used (enable) or not used (disable) when transmitting frames.

Default

For 16 Mbps and auto speed-detection ports, the default configuration is enable Early Token Release.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

Early Token Release cannot be enabled for 4 Mbps ports. Enabling or disabling Early Token Release on a port will cause the port to be closed and reopened.

Example

The following example shows how to enable Early Token Release on port 2 on module 3:

 
Console> (enable) set tokenring etr 3/2 enable

 
Port 3/2 Early Token Release enabled.

The following example shows how to disable Early Token Release on port 2 on module 3:

 
Console> (enable) set tokenring etr 3/2 disable

 
Port 3/2 Early Token Release disabled.

Related Commands

show tokenring

set tokenring help

Use the set tokenring help privileged command to list the Token Ring-specific set commands with brief descriptions of their functions.

: set tokenring help

Syntax Description

This command has no arguments or keywords.

Default

This command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

The set tokenring help command lists the Token Ring set commands that are available in privileged mode.

Example

The following example shows how to list the Token Ring set commands that are available in privileged mode:

 
Console> (enable) set tokenring help

 
Set tokenring commands:

 
----------------------------------------------------------------------------

 
set tokenring acbits           Set the AC bits

 
set tokenring configloss       Specify the behavior in case of lots of failures

 
set tokenring etr              Enable/disable Early Token Release

 
set tokenring help             Show this help message

 
set tokenring portmode         Set port mode

 
set tokenring priority         Set port priority

 
Console> (enable)

Related Commands

set help

set tokenring locallearning

Use the set tokenring locallearning privileged command to enable or disable local MAC address learning on a Token Ring port.

: set tokenring locallearning mod_num/port_num enable | disable

Syntax Description

mod_num	Number of the module.
enable	Keyword used to enable local MAC address learning on a Token Ring port.
disable	Keyword used to disable local MAC address learning on a Token Ring port.

Default

The default configuration is enable.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

We recommend that you use the set tokenring locallearning command only in those rare circumstances in which network communications are disrupted because of invalid frames. This command should be used in conjunction with the set tokenring portaging and set tokenring acbits commands.

The set tokenring locallearning command allows you to enable or disable local MAC address learning on a Token Ring port. The default is for local address learning to be enabled.

When local address learning is enabled, the value of the address recognized (A) bit and the frame copied (C) bit in LLC frames is set by the ports on the Token Ring module based on whether the frame was actually forwarded. However, when local address learning is disabled, the AC bits cannot be set by the ports on the Token Ring module based on whether the frame was forwarded because all frames are forwarded to the Catalyst 5000 series switching backplane.

Therefore, when local address learning is disabled on a Token Ring port, the AC bits must be set based on the type of frame that has been received. When you disable local address learning on a Token Ring port, the default is for the AC bits to always be set on LLC frames, however you can configure how the AC bits are to be set using the set tokenring acbits command.

Example

The following example shows how to disable local MAC address learning port 2 on module 3:

 
Console> (enable) set tokenring locallearning 3/2 disable

 
Warning: Resetting acbit value to ALWAYS: 3/2

 
Local learning disabled for port 3/2

 
Console> (enable)

Related Commands

set tokenring acbits
set tokenring portaging

set tokenring portaging

Use the set tokenring portaging privileged command to configure fast port aging on a Token Ring port.

: set tokenring portaging mod_num/port_num agingtime

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
agingtime	Time (in seconds) an inactive MAC address will remain in the port's address table. Possible values are 0 and 5 through 65535 seconds. Zero indicates the Token Ring module port address table entries are aged out using the CAM aging time for the corresponding VLAN that has been configured using the set cam agingtime command. To use the fast port aging feature effectively, we recommend that you configure an aging limit of 10.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

We recommend that you use the set tokenring portaging command only in those rare circumstances in which network communications are disrupted because of invalid frames. This command should be used in conjunction with the set tokenring locallearning and set tokenring acbits commands.

When in a network environment in which a device is sending invalid frames, you can ensure that the Token Ring module port address tables contain correct MAC address entries by rapidly aging out the erroneous entries using the set tokenring portaging command. Rapidly aging out the Token Ring module port address table ensures that the Token Ring module port address tables do not contain invalid entries which might affect the Catalyst 5000 series switch and network communication.

The aging limit you define determines when inactive MAC addresses are removed from a port address table. The aging limit is the time (in seconds) a MAC address remains in the port's address table. Possible values are 0 and 5 through 65535 seconds. The default is 0. Zero indicates the Token Ring module port address table entries are aged out using the CAM aging time for the corresponding VLAN that has been configured using the set cam agingtime command. For more information about the set cam agingtime command, see the Catalyst 5000 Series Command Reference.

To use the fast port aging feature effectively, we recommend that you configure an aging limit of 10.

Example

The following example shows how to specify address aging limits for port 2 on module 3:

 
Console> (enable) set tokenring portaging 3/2 10

 
Agingtime set to 10 sec for port 3/2

 
Console> (enable)

Related Commands

set tokenring acbits
set tokenring locallearning

set tokenring portmode

Use the set tokenring portmode privileged command to specify the connection type and access protocol being used by a port.

: set tokenring portmode mod_num/port_num {auto | fdxcport | hdxcport | fdxstation |
hdxstation | riro}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
auto	Keyword used to have the port detect the mode of connection.
fdxcport	Keyword used to set the port to operate as a concentrator port in full duplex mode.
hdxcport	Keyword used to set the port to operate as a concentrator port in half duplex mode.
fdxstation	Keyword used to set the port to operate as a station in full duplex mode.
hdxstation	Keyword used to set the port to operate as a station in half duplex mode.
riro	This parameter is applicable to fiber modules only.

Default

The default configuration is auto.

Command Type

Switch command

Command Mode

Privileged

Example

The following example shows how to set the port mode to autosensing on port 1 on module 4 and to set port 2 on module 4 to operate as a concentrator port in full-duplex mode:

 
Console> (enable) set tokenring portmode 4/1 auto

 
Port 4/1 mode set to auto.

 
Console> (enable) set tokenring portmode 4/2 fdxcport

 
Port 4/2 mode set to fdxcport.

Related Commands

show tokenring

set tokenring priority

Use the set tokenring priority privileged command to specify the highest Token Ring frame priority that shall go to the low-priority transmit queue and the minimum Token Ring frame priority that will be used when requesting a token.

: set tokenring priority mod_num/port_num {threshold thresh_num | minxmit min_num}

Syntax Description

mod_num	Number of the module.
port_num	Number of the port on the module.
threshold thresh_num	Keyword used to specify the priority queue threshold. Valid values are 0 to 7. The default is 3.
minxmit min_num	Keyword used to specify the minimum frame priority to be used. Valid values are 0 to 6. The default is 4.

Default

The default configuration for threshold is 3. The default configuration for minxmit is 4.

Command Type

Switch command

Command Mode

Privileged

Example

The following example shows how to set the priority threshold and minimum priority levels on port 2 on module 4:

 
Console> (enable) set tokenring priority 4/2 threshold 6

 
Port 2 priority threshold set to 6.

 
Console> (enable) set tokenring priority 4/2 minxmit 5

 
Port 2 priority minxmit set to 5.

Related Commands

show tokenring

set tokenring reduction

Use the set tokenring reduction privileged command to reduce broadcast storms in an externally looped network.

: set tokenring reduction {enable | disable}

Syntax Description

enable | disable

Keywords used to turn broadcast reduction on (enable) or off (disable).

Default

The default configuration is enabled.

Command Type

Switch command

Command Mode

Privileged

Example

The following example shows how to enable and disable ARE reduction:

 
Console> (enable) set tokenring reduction enable

 
Console> (enable) set tokenring reduction disable

set vlan

Use the set vlan privileged command to group ports into a virtual LAN.

: set vlan vlan_num mod/ports

: set vlan vlan_num [name name

Task	Command
Set the bridge forward delay for a VLAN.	set spantree fwddelay delay [vlan]
Set the bridge hello time for a VLAN	set spantree hello interval
Set the bridge maximum aging time for a VLAN.	set spantree maxage agingtime [vlan]
Set the bridge priority for a VLAN.	set spantree priority bridge_priority [vlan]
Configure a physical port that is connected to a single workstation or PC to start faster when it is connected.	set spantree portfast mod_num/port_num {enable \| disable}

Field	Description
Destination	Destination port to which the source port traffic is being copied.
Admin Source	Source port whose traffic is being monitored.
Oper Source	Source port or the ports within a TrCRF whose traffic is being monitored.
Direction	Indicates whether transmit, receive, or transmit/receive information is being monitored.
Incoming Packets	Status of whether reception of normal incoming packets on the SPAN destination port is enabled or disabled.
Multicast	Status of whether monitoring multicast traffic is enabled or disabled.

Protocol Identifier	Identifies the protocol. This field contains the value zero.
Version	Identifies the version. This field contains the value zero.
Message Type	Identifies the message type. This field contains the value zero.
Flags	1-byte field, of which only the first two bits are used. The topology change (TC) bit signals a topology change. The topology change acknowledgment (TCA) bit is set to acknowledge receipt of a configuration message with the TC bit set. This field is not valid for IBM STP BPDUs.
Root ID	Identifies the root bridge by listing its 2-byte priority followed by its 6-byte ID.
Root Path Cost	Cost of the path from the bridge sending the configuration message to the root bridge.
Bridge ID	Priority and ID of the bridge sending the message.
Port ID	Port number (IEEE or Cisco STP BPDU) or the ring and bridge number (IBM STP BPDU) from which the configuration message was sent. This field allows loops created by multiple attached bridges to be detected and corrected.
Message Age	Indicates the amount of time that has elapsed since the root sent the configuration message on which the current configuration message is based.
Max Age	Indicates when the current configuration message should be deleted.
Hello Time	Indicates the time between root bridge configuration messages.
Forward Delay	Indicates the length of time that bridges should wait before transitioning to a new state after a topology change. If a bridge transitions too soon, it is possible that not all network links will be ready to change their state and loops can result.

TrCRF Bridging Mode	TrCRF	TrBRF
SRB	Runs the IEEE STP. Processes IBM STP BPDUs from external bridges.	Performs as a source-route bridge. Runs the IBM STP to external bridges. Drops transparent IEEE STP BPDUs of the TrCRF.
SRT	Runs the Cisco STP. Replaces bridge group address of destination address field with a Cisco-specific group address to prevent external bridges from analyzing TrCRF BPDUs. Generates BPDUs with the Routing Information Identifier bit in the source address field set in the outbound frame and a 2-byte RIF added. This frame format ensures that the TrCRF remains local to the logical ring and is not transparently bridged or source routed to other LANs. Only TrCRFs connected via physical loops receive the BPDUs. Processes IEEE STP BPDUs from external bridges.	Performs as a source-route transparent bridge. Forwards transparent and source-route traffic. Forwards source-route traffic to all other TrCRFs in the TrBRF whether they be in SRT or SRB mode.

Hierarchical Navigation

Cisco Catalyst 5000 Series Switches

Copper Token Ring Module Configuration Note, Release 3.3(1)

Downloads

Table of Contents

Catalyst 5000 Series Token Ring Module Configuration Note

Document Contents

What is the Catalyst 5000 Switch?

What is the Token Ring Switch Module?

Bridging Modes

Token Ring Port Operation

Transmission Speed Adaption

Dedicated Token Ring Support

Transmission Priority Queues

Filtering

ARE Reduction

Virtual LAN Support

STP Support

Configuration and Management

SNMP-Based Management

CiscoView Support

RMON Support

SPAN Support

Soft Error Monitoring and Remove Adapter Support

Token Ring Module Requirements

Token Ring Module Physical Characteristics

Maximum Configuration

Status and Activity Indicators

Planning for Installation

Preparing Network Connections

Token Ring Cabling Recommendations

Cabling Length Recommendations for Dedicated-Media LAN Segments

Cable Length and Lobe Wiring Rules for Shared-Media LAN Segments

Number of Attaching Devices

Twisted-Pair Cable Pinouts

Token Ring Connection Equipment

Following Safety Recommendations

Safety with Electricity

Preventing ESD

Hot-Swapping Overview

Avoiding Problems When Inserting and Removing a Switching Module

Installing the Catalyst 5000 Series Token Ring Module

Required Tools

Removing Switching Modules or Module Fillers

Installing the Token Ring Module

Hot-Swapping Screen Display Samples

Customizing the Token Ring Module Configuration

Default Configuration

Entering Enable Privilege Mode

Configuring Token Ring Port Parameters

Setting the Port Name

Setting the Frame Priority Levels

Setting the Port Speed

Setting the Port Transmission Mode

Setting Early Token Release

Setting Address Recognized/Frame Copied Bits

Setting Configuration Loss Thresholds

Verifying the Token Ring Port Configuration

Troubleshooting a Faulty Port Status

Enabling and Disabling ARE Reduction

Configuring VLANs

Token Ring VLANs

Adding or Changing TrBRF Parameters

Adding or Changing TrCRF Parameters

Undistributed TrCRFs

Distributed TrCRFs

Backup TrCRFs

Specifying a Backup TrCRF

Enabling the Ability to Configure a Distributed TrCRF

Specifying All-Route Explorer and Spanning-Tree Explorer Maximum Hop Counts

Grouping Ports to a TrCRF

Verifying Token Ring VLAN Parameters

Clearing a Token Ring VLAN

Configuring STP

Enabling the STP

Configuring STP for a TrBRF

Specifying the STP Functional Address

Setting the Port State

Configuring the Port Priority

Configuring the Port Cost