Cisco Catalyst 5000 Series Switches

To connect the cables, perform the following steps:

Step 2   Label each end of the cable so that it will be easy to find the device if you have to troubleshoot a network problem. Suggested information for this label includes the following:

Customizing the Catalyst 5000 Series Fiber Token Ring Module Configuration

The Catalyst 5000 series fiber 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 fiber Token Ring module, you can do so.

This section describes how to use the 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.

This section discusses the following topics:

Default Configuration

The default values of the fiber Token Ring module features are:

Entering Enable Privileged Mode

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

To enter privileged mode:

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.

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

By default, no names are assigned to the ports on the Catalyst 5000 series fiber 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 Token Ring 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:

Setting the Frame Priority Levels

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

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:

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 ports 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:

Setting the Port Transmission Mode

The ports of the Catalyst 5000 series fiber 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.

Any of the 16 ports on the fiber Token Ring module can be configured for RI/RO out mode. For more information on RI/RO ports, see the "Ring In/Ring Out Ports" section.

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:

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:

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 set the AC bits for a port, issue the following command in privileged mode:

set tokenring acbits mod_num/port_num {enable | disable}

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

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:

Verifying the Token Ring Port Configuration

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

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

Table 3 describes the information returned by the show port command.s

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

Table 3 describes the information returned by the show tokenring command issued with a module and port number specified.

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 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.

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 fiber 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.

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:

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.

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

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:

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] [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 8 illustrates the undistributed TrCRF.

Figure 8   Undistributed TrCRFs

Distributed TrCRFs

A distributed TrCRF contains ports on different switches as illustrated in Figure 9. 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.

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.

Figure 9   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 10 illustrates the backup TrCRF.

Figure 10   Backup TrCRF

When configuring a TrCRF, keep the following in mind:

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.

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:

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:

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.

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:

Specifying ARE and Spanning-Tree Explorer Maximum Hop Counts

You can specify the maximum hop count for ARE 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:

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 fiber 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...

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

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:

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

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

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:

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

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.

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.

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

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. By default, the spanning-tree support is enabled.

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 the "STP" section.

Enabling the STP

By default, STP is enabled for VLANs. However, if necessary, you can manually enable and disable the STP support for individual TrBRFs and TrCRFs.

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:

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:

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:

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:

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 STP 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:

The port states occur as follows:

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:

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:

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:

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:

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:

Configuring Additional STP Parameters

You can configure additional STP parameters using the set spantree command. Table 5 lists the types of spanning tree information you can configure and the command you use.

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:

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

Configuring Soft Error Monitoring

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 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

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

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.

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

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]

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

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

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.

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

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]

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

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:

Table 7 describes the information returned by the show span command.

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 define filters that:

There are two types of filters that you can configure for the Catalyst 5000 series fiber 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.

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.

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:

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:

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:

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

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 the ports on module 3, issue the following command:

show port filter 3

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

Table 9 describes the information returned by the show port filter command issued with a module specified.s

Managing the Catalyst 5000 Series Fiber Token Ring Module

Use the following show commands to complete the listed tasks:

Updating Software

As enhancements are made to the Catalyst 5000 series fiber Token Ring module, you may need to update the software or microcode that is contained in the Catalyst 5000 series fiber 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 2   On Sun workstations, make sure the /etc/inetd.conf file contains the following line:

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

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:

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:

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 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

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 fiber Token Ring module supports the following bridging modes:

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.

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 STP.

Source-Route Switching

Similar to a transparent bridge, the Catalyst 5000 series fiber 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:

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 of this configuration note.

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.

As shown in Figure 11, 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.

Figure 11   Token Ring VLANs

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 "VLAN 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:

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 12 shows the format of the fields inside a BPDU.

Catalyst 5000 Series Fiber Token Ring Module Spanning-Tree Support

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

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

Table 11  

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:

The IEEE 802.1d STP BPDU format is:

Transparent Bridging

When a bridge connection is transparent mode:

Source-Route Switching

When a bridge connection is source-route switching:

Source-Route Transparent Bridging

When a bridge connection is source-route transparent:

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 IBM STP BPDU format is:

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

Table 12   Cisco STP and Bridging Modes

The Cisco STP BPDU format is:

Spanning-Tree BPDU Formats Summary

For each BPDU format:

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 Fiber Token Ring Module Command Reference

This section lists and describes commands specific to the Catalyst 5000 series fiber Token Ring module as well as existing Catalyst 5000 series switch commands that have been altered for the Catalyst 5000 series fiber Token Ring module. For a complete description of all the Catalyst 5000 series switch commands and the switch command-line interface, 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

Default

The command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Example

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

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

Default

The command has no default setting.

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

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.

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:

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

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:

Related Commands

set station softerror
show station softerror counters

set help

Use the set help normal or privileged command to list the set commands with brief descriptions of their functions.

set help

Syntax Description

This command has no arguments or keywords.

Default

This command has no default setting.

Command Type

Switch command

Command Mode

Normal and privileged

Usage Guidelines

In normal mode, the set help command lists the set commands available in normal mode. In privileged mode, the set help command lists the set commands available in privileged mode.

Examples

The following example shows how to list the set commands available in normal mode:

The following example shows how to list the set commands available in privileged mode:

Related Commands

disable (Switch Command)
enable (Switch Command)

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

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:

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

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 3 and 4 on module 3 to 4 Mbps and 16 Mbps:

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

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:

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:

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:

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 STP address.

set spantree multicast-address vlan_num {ieee | ibm}

Syntax Description

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:

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

Default

The default configuration is as follows:

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 100:

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

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:

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

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:

Example

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

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

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:

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

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

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.

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

Default

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

Command Type

Switch command

Command Mode

Privileged

Usage Guidelines

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.

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.

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

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:

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

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:

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

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:

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

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:

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

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