Cisco Connected Grid Ethernet Switch Module Interface Card Software Configuration Guide

UNI, NNI, and ENI Port Types

The CGR 2010 ESM supports user-network interfaces (UNIs), network node interfaces (NNIs), and enhanced network interfaces (ENIs).

• UNIs are typically connected to a host, such as a PC or a Cisco IP phone.
• NNIs are typically connected to a router or to another switch or switch module
• ENIs have the same functionality as UNIs, but can be configured to support protocol control packets for Cisco Discovery Protocol (CDP), Spanning-Tree Protocol (STP), Link Layer Discovery Protocol (LLDP), and EtherChannel Link Aggregation Control Protocol (LACP).

Note By default, upon startup, all ports on the switch module are enabled as NNIs. The default status for an NNI is administratively up to allow a service provider remote access to the switch module during initial configuration.

The default state for a UNI or ENI is administratively down to prevent unauthorized users from gaining access to other ports as you configure the switch module. Traffic is not switched between these ports, and all arriving traffic at UNIs or ENIs must leave on NNIs to prevent a user from gaining access to another user’s private network. If it is appropriate for two or more UNIs or ENIs to exchange traffic within the switch module, the UNIs and ENIs can be assigned to a community VLAN. For instructions on how to configure community VLANs, see Chapter11, “VLAN Configuration”

Note Even though the default state for a UNI or ENI is shutdown, entering the default interface interface-id command changes the port to the enabled state.

A port can be reconfigured from UNI to NNI or ENI and the reverse. When a port is reconfigured as another interface type, it inherits all the characteristics of that interface type. When you reconfigure a UNI or ENI to be an NNI, you must enable the port before it becomes active.

Changing the port type from UNI to ENI does not affect the administrative state of the port. If the UNI status is shut down, it remains shut down when reconfigured as an ENI; if the port is in a no shutdown state, it remains in the no shutdown state. At any time, all ports on the switch module are either UNI, NNI, or ENI.

Port-Based VLANs

A VLAN is a switched network that is logically segmented by function, team, or application, without regard to the physical location of the users. For more information about VLANs, see Chapter11, “VLAN Configuration” Packets received on a port are forwarded only to ports that belong to the same VLAN as the receiving port. Network devices in different VLANs cannot communicate with one another without a Layer 3 device to route traffic between the VLANs.

VLAN partitions provide hard firewalls for traffic in the VLAN, and each VLAN has its own MAC address table. A VLAN comes into existence when a local port is associated with the VLAN ID or when a user creates te VLAN ID.

To isolate VLANs of different customers in a service-provider network, the switch module uses UNI-ENI VLANs. UNI-ENI VLANs isolate user network interfaces (UNIs) or enhanced network interfaces (ENIs) on the switch module from UNIs or ENIs that belong to other customer VLANs. There are two types of UNI-ENI VLANs:

• UNI-ENI isolated VLAN—This is the default VLAN state for all VLANs created on the switch module. Local switching does not occur among UNIs or ENIs on the switch module that belong to the same UNI-ENI isolated VLAN.
• UNI-ENI community VLAN—Local switching is allowed among UNIs and ENIs on the switch module that belong to the same UNI community VLAN. If UNIs or ENIs belong to the same customer, and you want to switch packets between the ports, you can configure the common VLAN as a UNI-ENI community VLAN.

Note Local switching takes place between ENIs and UNIs in the same community VLAN. Because you can enable spanning tree on ENIs, but not on UNIs, you should use caution when configuring ENIs and UNIs in the same community VLAN. UNIs are always in the forwarding state.

For more information about UNI VLANs, see the “UNI-ENI VLANs” section.

To configure VLANs, use the vlan vlan-id global configuration command to enter VLAN configuration mode. The VLAN configurations for VLAN IDs 1 to 1005 are saved in the VLAN database. Extended-range VLANs (VLAN IDs 1006 to 4094) are not added to the VLAN database. VLAN configuration is saved in the switch module running configuration, and you can save it in the switch module startup configuration file by entering the copy running-config startup-config privileged EXEC command.

Add ports to a VLAN by using the switchport interface configuration commands:

• Identify the interface
• For a trunk port, set trunk characteristics, and if desired, define the VLANs to which it can belong
• For an access port, set and define the VLAN to which it belongs
• For a tunnel port, set and define the VLAN ID for the customer-specific VLAN tag. See Chapter13, “IEEE 802.1Q and Layer 2 Protocol Tunneling Configuration”

Switch Module Ports

Switch module ports are Layer 2 only interfaces associated with a physical port. Switch module ports belong to one or more VLANs. A switch module port can be an access port, a trunk port, a private-VLAN port, or a tunnel port. You can configure a port as an access port or trunk port. You configure a private VLAN port as a host or promiscuous port that belongs to a private-VLAN primary or secondary VLAN. (Only NNIs can be configured as promiscuous ports.) You must manually configure tunnel ports as part of an asymmetric link connected to an IEEE 802.1Q trunk port. Switch module ports are used for managing the physical interface and associated Layer 2 protocols and do not handle routing or bridging.

Configure switch module ports by using the switchport interface configuration commands. Use the switchport command with no keywords to put an interface that is in Layer 3 mode into Layer 2 mode.

Note When you put an interface that is in Layer 3 mode into Layer 2 mode, the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration.

For detailed information about configuring access port and trunk port characteristics, see Chapter11, “VLAN Configuration”

For more information about tunnel ports, see Chapter13, “IEEE 802.1Q and Layer 2 Protocol Tunneling Configuration”

Access Ports

An access port belongs to and carries the traffic of only one VLAN. Traffic is received and sent in native formats with no VLAN tagging. Traffic arriving on an access port is assumed to belong to the VLAN assigned to the port. If an access port receives an 802.1Q tagged packet, the packet is dropped, and the source address is not learned. 802.1x can also be used for VLAN assignment.

Two types of access ports are supported:

• Static access ports are manually assigned to a VLAN
• VLAN membership of dynamic access ports is learned through incoming packets. By default, a dynamic access port is a member of no VLAN, and forwarding to and from the port is enabled only when the VLAN membership of the port is discovered. UNIs begin forwarding packets as soon as they are enabled. Dynamic access ports on the switch module are assigned to a VLAN by a VLAN Membership Policy Server (VMPS). The VMPS can be a Catalyst 6500 series switch; the switch module cannot be a VMPS server. Dynamic access ports for VMPS are only supported on UNIs and ENIs.

Trunk Ports

An 802.1Q trunk port carries the traffic of multiple VLANs and by default is a member of all VLANs in the VLAN database. A trunk port supports simultaneous tagged and untagged traffic. An 802.1Q trunk port is assigned a default Port VLAN ID (PVID), and all untagged traffic travels on the port default PVID. All untagged traffic and tagged traffic with a NULL VLAN ID are assumed to belong to the port default PVID. A packet with a VLAN ID equal to the outgoing port default PVID is sent untagged. All other traffic is sent with a VLAN tag.

Although by default a trunk port is a member of multiple VLANs, you can limit VLAN membership by configuring an allowed list of VLANs for each trunk port. The list of allowed VLANs does not affect any other port but the associated trunk port. By default, all possible VLANs (VLAN ID 1 to 4094) are in the allowed list. A trunk port can become a member of a VLAN only if the VLAN is in the enabled state.

For more information about trunk ports, see Chapter11, “VLAN Configuration”

Tunnel Ports

Tunnel ports are used in 802.1Q tunneling to segregate the traffic of customers in a service-provider network from other customers who are using the same VLAN number. You configure an asymmetric link from a tunnel port on a service-provider edge switch module to an 802.1Q trunk port on the customer switch module. Packets entering the tunnel port on the edge switch module, already IEEE 802.1Q-tagged with the customer VLANs, are encapsulated with another layer of an 802.1Q tag (called the metro tag), containing a VLAN ID unique in the service-provider network, for each customer. The double-tagged packets go through the service-provider network keeping the original customer VLANs separate from those of other customers. At the outbound interface, also a tunnel port, the metro tag is removed, and the original VLAN numbers from the customer network are retrieved.

Tunnel ports cannot be trunk ports or access ports and must belong to a VLAN unique to each customer.

For more information about tunnel ports, see Chapter13, “IEEE 802.1Q and Layer 2 Protocol Tunneling Configuration”

Routed Ports

A routed port is a physical port that acts like a port on a router; it does not have to be connected to a router. A routed port is not associated with a particular VLAN, as is an access port. A routed port behaves like a regular router interface, except that it does not support VLAN subinterfaces. Routed ports can be configured with a Layer 3 routing protocol. A routed port is a Layer 3 interface only and does not support Layer 2 protocols, such as STP.

Configure routed ports by putting the interface into Layer 3 mode with the no switchport interface configuration command. Then assign an IP address to the port, enable routing, and assign routing protocol characteristics by using the ip routing and router protocol global configuration commands.

Configure routed ports by putting the interface into Layer 3 mode with the no switchport interface configuration command. Then assign an IP address to the port, enable routing, and assign routing protocol characteristics by using the ip routing and router protocol global configuration commands.

Note Entering a no switchport interface configuration command shuts down the interface and then re-enables it, which might generate messages on the device to which the interface is connected. When you put an interface that is in Layer 2 mode into Layer 3 mode, the previous configuration information related to the affected interface might be lost.

The number of routed ports that you can configure is not limited by software. However, the interrelationship between this number and the number of other features being configured might impact CPU performance because of hardware limitations. See the “Configuring Layer 3 Interfaces” section for information about what happens when hardware resource limitations are reached.

For more information about IP unicast and multicast routing and routing protocols, see:

• Chapter 18, “Configuring IP Unicast Routing” in the Cisco CGS 2520 Switch Software Configuration Guide

http://www.cisco.com/en/US/docs/switches/connectedgrid/cgs2520/software/release/12_2_53_ex/configuration/guide/swiprout.html

Chapter 19, “Configuring IPv6 Unicast Routing” in the Cisco CGS 2520 Switch Software Configuration Guide

http://www.cisco.com/en/US/docs/switches/connectedgrid/cgs2520/software/release/12_2_53_ex/configuration/guide/swipv6.html

Note For full Layer 3 routing, you must have the IP services image installed on the switch module.

EtherChannel Port Groups

EtherChannel port groups treat multiple switch module ports as one switch module port. These port groups act as a single logical port for high-bandwidth connections between switches or between switches and servers. An EtherChannel balances the traffic load across the links in the channel. If a link within the EtherChannel fails, traffic previously carried over the failed link changes to the remaining links.

You can group multiple trunk ports into one logical trunk port, group multiple access ports into one logical access port, group multiple tunnel ports into one logical tunnel port, or group multiple routed ports into one logical routed port. Most protocols operate over either single ports or aggregated switch module ports and do not recognize the physical ports within the port group. Exceptions are the Cisco Discovery Protocol (CDP), and Link Aggregation Control Protocol (LACP), which operate only on physical NNI or ENI ports.

When you configure an EtherChannel, you create a port-channel logical interface and assign an interface to the EtherChannel.

• For Layer 3 interfaces, you manually create the logical interface by using the interface port-channel global configuration command. Then you manually assign an interface to the EtherChannel by using the channel-group interface configuration command.
• For Layer 2 interfaces, use the channel-group interface configuration command to dynamically create the port-channel logical interface. This command binds the physical and logical ports together. For more information, see Chapter15, “EtherChannel Configuration and Link State Tracking”

Supported Protocols and Standards

The switch module uses these protocols and standards to support PoE:

• Cisco Discovery Protocol (CDP) with power consumption—The powered device notifies the switch module of the amount of power it is consuming. The switch module does not reply to the power-consumption messages. The switch module can only supply power to or remove power from the PoE port.
• Cisco intelligent power management—The powered device and the switch module negotiate through power-negotiation CDP messages for an agreed power-consumption level. The negotiation allows a high-power Cisco powered device, which consumes more than 7 W, to operate at its highest power mode. The powered device first boots up in low-power mode, consumes less than 7 W, and negotiates to obtain enough power to operate in high-power mode. The device changes to high-power mode only when it receives confirmation from the switch module.

High-power devices can operate in low-power mode on switches that do not support power-negotiation CDP.

Cisco intelligent power management is backward-compatible with CDP with power consumption; the switch module responds according to the CDP message that it receives. CDP is not supported on third-party powered devices; the switch module uses the IEEE classification to determine the power usage of the device.

• IEEE 802.3af—The major features of this standard are powered-device discovery, power administration, disconnect detection, and optional powered-device power classification. For more information, see the standard.

Powered-Device Detection and Initial Power Allocation

The switch module detects a Cisco pre-standard or an IEEE-compliant powered device when the PoE-capable port is in the no-shutdown state, PoE is enabled (the default), and the connected device is not being powered by an AC adaptor.

After device detection, the switch module determines the device power requirements based on its type:

• A Cisco pre-standard powered device does not provide its power requirement when the switch module detects it, so the switch module allocates 15.4 W as the initial allocation for power budgeting.

The initial power allocation is the maximum amount of power that a powered device requires. The switch module initially allocates this amount of power when it detects and powers the powered device. As the switch module receives CDP messages from the powered device and as the powered device negotiates power levels with the switch module through CDP power-negotiation messages, the initial power allocation might be adjusted.

• The switch module classifies the detected IEEE device within a power consumption class. Based on the available power in the power budget, the switch module determines if a port can be powered. Table 8-1 lists these power classification levels.

The switch module monitors and tracks requests for power and grants power only when it is available. The switch module tracks its power budget (the amount of power available on the switch module for PoE). The host CGR 2010 router performs power-accounting calculations and the switch module grants or denies power based on those calculations to keep the power budget up to date.

After power is applied to the port, the switch module uses CDP to determine the actual power consumption requirement of the connected Cisco powered devices, and the switch module adjusts the power budget accordingly. This does not apply to third-party PoE devices. The switch module processes a request and either grants or denies power. If the request is granted, the switch module updates the power budget. If the request is denied, the switch module ensures that power to the port is turned off, generates a syslog message, and updates the LEDs. Powered devices can also negotiate with the switch module for more power.

If the switch module detects a fault caused by an undervoltage, overvoltage, overtemperature, oscillator-fault, or short-circuit condition, it turns off power to the port, generates a syslog message, and updates the power budget and LEDs.

Power Management Modes

The switch module supports these PoE modes:

• Auto—The switch module automatically detects if the connected device requires power. If the switch module discovers a powered device connected to the port and if the switch module has enough power, it grants power, updates the power budget, turns on power to the port on a first-come, first-served basis, and updates the LEDs. For LED information, see the Cisco Connected Grid 10-Port Ethernet Switch Module Interface Card Getting Started Guide.

If the switch module has enough power for all the powered devices, they all come up. If enough power is available for all powered devices connected to the switch module, power is turned on to all devices. If there is not enough available PoE, or if a device is disconnected and reconnected while other devices are waiting for power, it cannot be determined which devices are granted or are denied power.

If granting power would exceed the system power budget, the switch module denies power, ensures that power to the port is turned off, generates a syslog message, and updates the LEDs. After power has been denied, the switch module periodically rechecks the power budget and continues to attempt to grant the request for power.

If a device being powered by the switch module is then connected to wall power, the switch module might continue to power the device. The switch module might continue to report that it is still powering the device whether the device is being powered by the switch module or receiving power from an AC power source.

If a powered device is removed, the switch module automatically detects the disconnect and removes power from the port. You can connect a nonpowered device without damaging it.

You can specify the maximum wattage that is allowed on the port. If the IEEE class maximum wattage of the powered device is greater than the configured maximum value, the switch module does not provide power to the port. If the switch module powers a powered device, but the powered device later requests through CDP messages more than the configured maximum value, the switch module removes power to the port. The power that was allocated to the powered device is reclaimed into the global power budget. If you do not specify a wattage, the switch module delivers the maximum value. Use the auto setting on any PoE port. The auto mode is the default setting.

• Static—The switch module pre-allocates power to the port (even when no powered device is connected) and guarantees that power will be available for the port. The switch module allocates the port configured maximum wattage, and the amount is never adjusted through the IEEE class or by CDP messages from the powered device. Because power is pre-allocated, any powered device that uses less than or equal to the maximum wattage is guaranteed to be powered when it is connected to the static port. The port no longer participates in the first-come, first-served model.

However, if the powered-device IEEE class is greater than the maximum wattage, the switch module does not supply power to it. If the switch module learns through CDP messages that the powered device needs more than the maximum wattage, the powered device is shutdown.

If you do not specify a wattage, the switch module pre-allocates the maximum value. The switch module powers the port only if it discovers a powered device. Use the static setting on a high-priority interface.

• Never—The switch module disables powered-device detection and never powers the PoE port even if an unpowered device is connected. Use this mode only when you want to make sure power is never applied to a PoE-capable port, making the port a data-only port.

For information on configuring a PoE-enabled port, see the “Configuring a Power Management Mode on a PoE-Enabled Port” section.

Power Monitoring and Power Policing

When policing of the real-time power consumption is enabled, the switch module takes action when a powered device consumes more power than the maximum amount allocated, also referred to as the cutoff-power value.

When PoE is enabled, the switch module senses the real-time power consumption of the powered device. The switch module monitors the real-time power consumption of the connected powered device; this is called power monitoring or power sensing. The switch module also polices the power usage with the power policing feature.

Power monitoring is backward-compatible with Cisco intelligent power management and CDP-based power consumption. It works with these features to ensure that the PoE port can supply power to the powered device. For more information about these PoE features, see the “Supported Protocols and Standards” section.

The switch module senses the real-time power consumption of the connected device as follows:

1. The switch module monitors the real-time power consumption on individual ports.

2. The switch module records the power consumption, including peak power usage. The switch module reports the information through the CISCO-POWER-ETHERNET-EXT-MIB.

3. If power policing is enabled, the switch module polices power usage by comparing the real-time power consumption to the maximum power allocated to the device. For more information about the maximum power consumption, also referred to as the cutoff power, on a PoE port, see the next section, “Maximum Power Allocation (Cutoff Power) on a PoE Port.”

– If the device uses more than the maximum power allocation on the port, the switch module can either turn off power to the port, or the switch module can generate a syslog message and update the LEDs (the port LED is now blinking amber) while still providing power to the device based on the switch module configuration. By default, power-usage policing is disabled on all PoE ports.

– If error recovery from the PoE error-disabled state is enabled, the switch module automatically takes the PoE port out of the error-disabled state after the specified amount of time.

– If error recovery is disabled, you can manually re-enable the PoE port by using the shutdown and no shutdown interface configuration commands.

4. If policing is disabled, no action occurs when the powered device consumes more than the maximum power allocation on the PoE port, which could adversely affect the switch module.

Maximum Power Allocation (Cutoff Power) on a PoE Port

When power policing is enabled, the switch module determines one of the these values as the cutoff power on the PoE port in this order:

1. Manually when you set the user-defined power level that the switch module budgets for the port by using the power inline consumption default wattage global or interface configuration command.

2. Manually when you set the user-defined power level that limits the power allowed on the port by using the power inline auto max max-wattage or the power inline static max max-wattage interface configuration command.

3. Automatically when the switch module sets the power usage of the device by using CDP power negotiation or by the IEEE classification.

4. Automatically when the switch module sets the power usage to be the default value of 15400 mW.

To manually configure the cutoff-power value, use the first or second method in the previous list by entering the power inline consumption default wattage command or the power inline [auto | static max] max-wattage command.

If you are not manually configuring the cutoff-power value, the switch module automatically determines the value by using CDP power negotiation or the device IEEE classification, which is the third method in the previous list. If the switch module cannot determine the value by using one of these methods, it uses the default value of 15400 mW (the fourth method in the previous list).

Power Consumption Values

You can configure the initial power allocation and the maximum power allocation on a port. However, these values are only the configured values that determine when the switch module should turn on or turn off power on the PoE port. The maximum power allocation is not the same as the actual power consumption of the powered device. The actual cutoff power value that the switch module uses for power policing is not equal to the configured power value.

When power policing is enabled, the switch module polices the power usage at the switch module port, which is greater than the power consumption of the device. When you are manually set the maximum power allocation, you must consider the power loss over the cable from the switch module port to the powered device. The cutoff power is the sum of the rated power consumption of the powered device and the worst-case power loss over the cable.

The actual amount of power consumed by a powered device on a PoE port is the cutoff-power value plus a calibration factor of 500 mW (0.5 W). The actual cutoff value is approximate and varies from the configured value by a percentage of the configured value. For example, if the configured cutoff power is 12 W, the actual cutoff-value is 11.4 W, which is 5% less than the configured value.

We recommend that you enable power policing when PoE is enabled on your switch module. For example, if policing is disabled and you set the cutoff-power value by using the power inline auto max 6300 interface configuration command, the configured maximum power allocation on the PoE port is 6.3 W (6300 mW).

The switch module provides power to the connected devices on the port if the device needs up to 6.3 W. If the CDP-power negotiated value or the IEEE classification value exceeds the configured cutoff value, the switch module does not provide power to the connected device. After the switch module turns on power on the PoE port, the switch module does not police the real-time power consumption of the device, and the device can consume more power than the maximum allocated amount, which could adversely affect the switch module and the devices connected to the other PoE ports.

Dual-Purpose Ports

The Gigabit Ethernet port GE0/1 on the switch module consists of a pair of one RJ-45 connector (topmost port) and one SFP module connector (bottom port).

This dual-purpose port is considered as a single interface. The two connectors are not redundant interfaces—the switch module activates only one connector of the pair at a time.

If the dual-purpose port is configured as media-type RJ-45, the speed of the connection can be manually set to either 10, 100 or 1000 MBPS (10/100/1000Base-T specifications). The default speed setting is always enabled to AUTONEGOTIATION. It will automatically negotiate to whatever speed is set on the other end of the connection.

If the dual-purpose port is configured as media-type SFP, the speed is dependent on the module type you are using, either a 100FX or a 1000Base-X SFP module. The port will automatically detect the module, and the speed is set based on the media type. The other end of the connection will have to be of the same media type to establish the link.

Note Even when operating at 100 Mbps, the dual-purpose ports (and the SFP-only module ports) use the frame size that is set with the system mtu jumbo global configuration command.

By default, the dual-purpose ports and the SFP-only module ports are network node interfaces (NNIs). The switch module dynamically selects the dual-purpose port media type that first links up. However, you can use the media-type interface configuration command to manually select the RJ-45 connector or the SFP-module connector. For information about configuring a dual-purpose port, see the “Configuring a Dual-Purpose Port” section.

Note In auto-select mode, if both copper and fiber-optic signals are simultaneously detected, the switch module gives preference to SFP mode.

Each dual-purpose port has two LEDs:

• One shows the status of the SFP module port
• One shows the status of the RJ-45 port

The port LED is on for whichever connector is active. For more information about the LEDs, see the Cisco Connected Grid 10-Port Ethernet Switch Module Interface Card Getting Started Guide.

Connecting Interfaces

Devices within a single VLAN can communicate directly through any switch module. Ports in different VLANs cannot exchange data without going through a routing device. With a standard Layer 2 switch module, ports in different VLANs have to exchange information through a router.

By default, the CGR 2010 ESM provides VLAN isolation between UNIs or ENIs. UNIs and ENIs cannot exchange traffic unless they are changed to NNIs or assigned to a UNI-ENI community VLAN.

By using the switch module with routing enabled, when you configure both VLAN 20 and VLAN 30 with an SVI to which an IP address is assigned, packets can be sent from Host A to Host B directly through the switch module with no need for an external router (see Figure 8-2).

Figure 8-2 Connecting VLANs with the Switch Module

When the IP services image is running on the switch module, routing can be enabled on the switch module. Whenever possible, to maintain high performance, forwarding is done by the switch module hardware. However, only IP Version 4 packets with Ethernet II encapsulation can be routed in hardware. The routing function can be enabled on all SVIs and routed ports. The switch module routes only IP traffic. When IP routing protocol parameters and address configuration are added to an SVI or routed port, any IP traffic received from these ports is routed.

Procedures for Configuring Interfaces

These general instructions apply to all interface configuration processes.

Step 1 Enter the configure terminal command at the privileged EXEC prompt:

Step 2 Enter the interface global configuration command. Identify the interface type and the number of the connector. In this example, Fast Ethernet port 1 is selected:

Note You do not need to add a space between the interface type and interface number. For example, in the preceding line, you can specify either fastethernet 0/1, fastethernet0/1, fa 0/1, or fa0/1.

Step 3 If you are configuring a UNI or ENI, enter the no shutdown interface configuration command to enable the interface:

Step 4 Follow each interface command with the interface configuration commands that the interface requires. The commands that you enter define the protocols and applications that will run on the interface. The commands are collected and applied to the interface when you enter another interface command or enter end to return to privileged EXEC mode.

You can also configure a range of interfaces by using the interface range or interface range macro global configuration commands. Interfaces configured in a range must be the same type and must be configured with the same feature options.

Step 5 After you configure an interface, verify its status by using the show privileged EXEC commands listed in the “Monitoring and Maintaining the Interfaces” section.

Enter the show interfaces privileged EXEC command to see a list of all interfaces on or configured for the switch module. A report is provided for each interface that the device supports or for the specified interface.

Configuring a Range of Interfaces

You can use the interface range global configuration command to configure multiple interfaces with the same configuration parameters. When you enter the interface range configuration mode, all command parameters that you enter are attributed to all interfaces within that range until you exit this mode.

Beginning in privileged EXEC mode, follow these steps to configure a range of interfaces with the same parameters:

When using the interface range global configuration command, note these guidelines:

• Valid entries for port-range :

– vlan vlan-ID - vlan-ID, where the VLAN ID is 1 to 4094

– fastethernet module/{first port } - { last port }, where the module is always 0

– gigabitethernet module/{ first port } - { last port }, where the module is always 0

– port-channel port-channel-number - port-channel-number, where the port-channel-number is 1 to 48

Note When you use the interface range command with port channels, the first and last port channel number must be active port channels.

• The interface range command only works with VLAN interfaces that have been configured with the interface vlan command. The show running-config privileged EXEC command displays the configured VLAN interfaces. VLAN interfaces not displayed by the show running-config command cannot be used with the interface range command.
• All interfaces defined as in a range must be the same type (all Fast Ethernet ports, all Gigabit Ethernet ports, all EtherChannel ports, or all VLANs), but you can enter multiple ranges in a command.

This example shows how to use the interface range global configuration command to set the speed on ports 1 and 2 to 100 Mbps:

This example shows how to use a comma to add different interface type strings to the range to enable Fast Ethernet ports 1 to 3 and Gigabit Ethernet ports 1 and 2 to receive 802.3x flow control pause frames:

If you enter multiple configuration commands while you are in interface range mode, each command is executed as it is entered. The commands are not batched together and executed after you exit interface range mode. If you exit interface range configuration mode while the commands are being executed, some commands might not be executed on all interfaces in the range. Wait until the command prompt reappears before exiting interface range configuration mode.

Configuring and Using Interface Range Macros

You can create an interface range macro to automatically select a range of interfaces for configuration. Before you can use the macro keyword in the interface range macro global configuration command string, you must use the define interface-range global configuration command to define the macro.

Beginning in privileged EXEC mode, follow these steps to define an interface range macro:

Use the no define interface-range macro_name global configuration command to delete a macro.

When using the define interface-range global configuration command, note these guidelines:

• Valid entries for interface-range :

– vlan vlan-ID - vlan-ID, where the VLAN ID is 1 to 4094

– fastethernet module/{first port } - { last port }, where the module is always 0

– gigabitethernet module/{ first port } - { last port }, where the module is always 0

– port-channel port-channel-number - port-channel-number, where the port-channel-number is 1 to 48.

Note When you use the interface ranges with port channels, the first and last port channel number must be active port channels.

• You must add a space between the first interface number and the hyphen when entering an interface-range. For example, gigabitethernet 0/1 - 2 is a valid range; gigabitethernet 0/1-2 is not a valid range.
• The VLAN interfaces must have been configured with the interface vlan command. The show running-config privileged EXEC command displays the configured VLAN interfaces. VLAN interfaces not displayed by the show running-config command cannot be used as interface-ranges.
• All interfaces defined as in a range must be the same type (all Fast Ethernet ports, all Gigabit Ethernet ports, all EtherChannel ports, or all VLANs), but you can combine multiple interface types in a macro.

This example shows how to define an interface-range named enet_list to include ports 1 and 2 and to verify the macro configuration:

This example shows how to create a multiple-interface macro named macro1 and assign all of the interfaces in the range to a VLAN:

This example shows how to enter interface range configuration mode for the interface-range macro enet_list :

This example shows how to delete the interface-range macro enet_list and to verify that it was deleted

Default Ethernet Interface Configuration

Table 8-2 shows the Ethernet interface default configuration for NNIs, and Table 8-3 shows the Ethernet interface default configuration for UNIs and ENIs. For more details on the VLAN parameters listed in the table, see Chapter11, “VLAN Configuration” For details on controlling traffic to the port, see Chapter 26, “Configuring Port-Based Traffic Control” in the Cisco CGS 2520 Software Configuration Guide.

Configuring Layer 2 Parameters

To configure Layer 2 parameters, if the interface is in Layer 3 mode, you must enter the switchport interface configuration command without any parameters to put the interface into Layer 2 mode. This shuts down the interface and then re-enables it, which might generate messages on the device to which the interface is connected. When you put an interface that is in Layer 3 mode into Layer 2 mode, the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration.

Table 8-2 shows the Ethernet interface default configuration for NNIs:

Configuring the Port Type

By default, all the ports on the switch module are configured as NNIs.

You use the port-type interface configuration command to change the port types. You can change the ports on the switch module from NNIs to UNIs or ENIs. An ENI has the same characteristics as a UNI, but it can be configured to support CDP, STP, LLDP, and Etherchannel LACP.

When a port is changed from an NNI to a UNI or ENI, it inherits the configuration of the assigned VLAN, either in isolated or community mode. For more information about configuring UNI-ENI isolated and UNI-ENI community VLANs, see Chapter11, “VLAN Configuration”

When you change a port from NNI to UNI or ENI or the reverse, any features exclusive to the port type revert to the default configuration. For Layer 2 protocols, such as STP, CDP, and LLDP, the default for UNIs and ENIs is disabled (although they can be enabled on ENIs) and the default for NNIs is enabled.

Note By default, the switch module sends keepalive messages on UNI s and ENIs and does not send keepalive messages on NNIs. Changing the port type from UNI or ENI to NNI or from NNI to UNI or ENI has no effect on the keepalive status. You can change the keepalive state from the default setting by entering the [no] keepalive interface configuration command. If you enter the keepalive command with no arguments, keepalive packets are sent with the default time interval (10 seconds) and number of retries (5). Entering the no keepalive command disables keepalive packets on the interface.

Beginning in privileged EXEC mode, follow these steps to configure the port type on an interface:

Entering the no port-type or default port-type interface configuration command returns the port to the default state: UNI for Fast Ethernet ports and NNI for Gigabit Ethernet ports.

This example shows how to change a port from a UNI to an NNI and save it to the running configuration:

Configuring Interface Speed and Duplex Mode

Ethernet interfaces on the switch module operate at 10, 100, or 1000 Mbps and in either full- or half-duplex mode. In full-duplex mode, two stations can send and receive traffic at the same time. Normally, 10-Mbps ports operate in half-duplex mode, which means that stations can either receive or send traffic.

Switch Module models include combinations of Fast Ethernet (10/100-Mbps) ports, Gigabit Ethernet (10/100/1000-Mbps) ports, and small form-factor pluggable (SFP) module slots supporting SFP modules.

These sections describe how to configure the interface speed and duplex mode:

• Speed and Duplex Configuration Guidelines
• Setting the Interface Speed and Duplex Parameters

Speed and Duplex Configuration Guidelines

When configuring an interface speed and duplex mode, note these guidelines:

• You can configure interface speed on Fast Ethernet (10/100-Mbps) and Gigabit Ethernet (10/100/1000-Mbps) ports. You can configure Fast Ethernet ports to full-duplex, half-duplex, or to autonegotiate mode. You can configure Gigabit Ethernet ports to full-duplex mode or to autonegotiate. You also can configure Gigabit Ethernet ports to half-duplex mode if the speed is 10 or 100 Mbps. Half-duplex mode is not supported on Gigabit Ethernet ports operating at 1000 Mbps.
• With the exception of when 1000BASE-T SFP modules are installed in the SFP module slots, you cannot configure speed on SFP module ports, but you can configure speed to not negotiate (nonegotiate) if connected to a device that does not support autonegotiation.

However, when a 1000BASE-T SFP module is in the SFP module slot, you can configure speed as 10, 100, or 1000 Mbps, or auto, but not as nonegotiate.

On a 100BASE-FX SFP module, you cannot configure the speed as nonegotiate.

• You cannot configure duplex mode on SFP module ports; they operate in full-duplex mode except in these situations:

– When a Cisco1000BASE-T SFP module is in the SFP module slot, you can configure duplex mode to auto or full. Half-duplex mode is supported with the auto setting.

– When a Cisco100BASE-FX SFP module is in the SFP module slot, you can configure duplex mode to half or full. Although the auto keyword is available, it puts the interface in half-duplex mode (the default for this SFP module) because the 100BASE-FX SFP module does not support autonegotiation.

• If both ends of the line support autonegotiation, we highly recommend the default setting of auto negotiation.
• If one interface supports autonegotiation and the other end does not, configure duplex and speed on both interfaces; do not use the auto setting on the supported side.
• When STP is enabled and a port is reconfigured, the switch module can take up to 30 seconds to check for loops. The port LED is amber while STP reconfigures. On the CGR 2010 ESM, STP is supported on NNIs by default and can be enabled on ENIs. UNIs do not support STP.

Caution Changing the interface speed and duplex mode configuration might shut down and re-enable the interface during the reconfiguration.

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Setting the Interface Speed and Duplex Parameters

Beginning in privileged EXEC mode, follow these steps to set the speed and duplex mode for a physical interface.

Note On dual-purpose ports, changing the interface type by entering the media-type interface configuration command removes the speed and duplex configurations. See the “Configuring a Dual-Purpose Port” section for information about speed and duplex setting on these ports.

Use the no speed and no duplex interface configuration commands to return the interface to the default speed and duplex settings (autonegotiate). To return all interface settings to the defaults, use the default interface interface-id interface configuration command.

This example shows how to set the interface speed to 10 Mbps and the duplex mode to half on a 10/100 Mbps port:

This example shows how to set the interface speed to 100 Mbps on a 10/100/1000 Mbps port:

Budgeting Power for Devices Connected to a PoE Port

The PoE power budget for the CGR 2010 ESM is shared among the modules installed in the Cisco CGR 2010 router chassis. The maximum PoE power for the whole router chassis is 61.6W. If there are two switch modules inserted into the router chassis, the total maximum power availability for both modules would be 61.6W, and one of the modules may get only a portion of that power budget.

Caution You should carefully plan your switch module power budget and make certain not to oversubscribe the power supply.

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Note When you manually configure the power budget, you must also consider the power loss over the cable between the switch module and the powered device.

The switch module supports four PoE ports in the Copper FastEthernet SKU. These four ports are always the first four ports (FE0/1 to FE0/4) among the total eight FastEthernet ports.

When Cisco powered devices are connected to PoE ports, the switch module uses Cisco Discovery Protocol (CDP) to determine the actual power consumption of the devices, and the switch module adjusts the power budget accordingly. The CDP protocol works with Cisco powered devices and does not apply to IEEE third-party powered devices. For these devices, when the switch module grants a power request, the switch module adjusts the power budget according to the powered-device IEEE classification.

If the powered device is a Class 0 (class status unknown) or a Class 3, the switch module budgets 15,400 milliwatts for the device, regardless of the actual amount of power needed. If the powered device reports a higher class than its actual consumption or does not support power classification (defaults to Class 0), the switch module can power fewer devices because it uses the IEEE class information to track the global power budget.

By using the power inline consumption wattage configuration command, you can override the default power requirement specified by the IEEE classification. The difference between what is mandated by the IEEE classification and what is actually needed by the device is reclaimed into the global power budget for use by additional devices. You can then extend the switch module power budget and use it more effectively.

For example, if the switch module budgets 15,400 milliwatts on each PoE port, you can connect only four Class 0 powered devices. If the device is actually using 5,000 milliwatts, you can connect up to 12 devices.

When you enter the power inline consumption default wattage command or the no power inline consumption default global configuration command, or the power inline consumption wattage command or the no power inline consumption interface configuration command this caution message appears:

Caution Interface: Misconfiguring the ‘power inline consumption/allocation’ command may cause damage to the switch module and void your warranty. Take precaution not to oversubscribe the power supply.

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We recommend you enable power policing.

If the power supply is over-subscribed to by up to 20 percent, the switch module continues to operate but its reliability is reduced. If the power supply is subscribed to by more than 20 percent, the short-circuit protection circuitry triggers and shuts the switch module down.

For more information about the IEEE power classifications, see the “Power Over Ethernet Ports” section.

Beginning in privileged EXEC mode, follow these steps to configure the amount of power budgeted to a powered device connected to each PoE port on a switch module:

To return to the default setting, use the no power inline consumption default global configuration command.

Note The CGR 2010 ESM does not support the power inline port priority command.

Beginning in privileged EXEC mode, follow these steps to configure amount of power budgeted to a powered device connected to a specific PoE port:

To return to the default setting, use the no power inline consumption interface configuration command.

Beginning in privileged EXEC mode, follow these steps to configure amount of power budgeted to a powered device connected to a specific PoE port:

To return to the default setting, use the no power inline consumption interface configuration command.

For information about the output of the show power inline consumption privileged EXEC command, see the Cisco IOS Interface Command Reference, Release 12.2.

Configuring a Dual-Purpose Port

The switch module provides dual-purpose ports that can be configured as 10/100/100 ports or as small form-factor pluggable (SFP) module ports. Each dual-purpose port is considered as a single interface with dual front ends (an RJ-45 connector and an SFP module connector).

Note Even when operating at 10 or 100 Mbps, the dual-purpose ports (and the SFP-only module ports) use the frame size that is set with the system mtu jumbo global configuration command.

Each dual-purpose port is considered as a single interface with dual front ends (an RJ-45 connector and an SFP module connector). The dual front ends are not redundant interfaces; the switch module activates only one connector of the pair.

By default, the dual-purpose ports are user-network interfaces (UNIs) and the SFP-only module ports are network node interfaces (NNIs).

By default, the switch module dynamically selects the dual-purpose port media type that first links up. However, you can use the media-type interface configuration command to manually select the RJ-45 connector or the SFP-module connector. In auto-select mode, the switch module gives preference to SFP mode if both copper and fiber-optic signals are simultaneously detected.

Beginning in privileged EXEC mode, follow these steps to select which dual-purpose media type to activate. This procedure is optional.

To return to the default setting, use the no media-type interface configuration command.

Changing the interface type removes the speed and duplex configurations. The switch module configures both media types to autonegotiate speed and duplex (the default). If you configure auto-select, you cannot configure the speed and duplex interface configuration commands.

When you configure sfp or rj45 media type, the non-configured type is disabled, even if there is a connector installed in that interface and no connector in the configured one.

When the media type is auto-select, the switch module uses these criteria to select the type:

Note An SFP is not installed until it has a fiber-optic or copper cable plugged in.

• If only one connector is installed, that interface is active and remains active until the media is removed or the switch module is reloaded.
• If you install both types of media in an enabled dual-purpose port, the switch module selects the active link based on which type is installed first.
• If both media are installed in the dual-purpose port, and the switch module is reloaded or the port is disabled and then reenabled through the shutdown and the no shutdown interface configuration commands, the switch module gives preference to the SFP module interface.

See the media-type interface configuration command in the Cisco IOS Interface Command Reference, Release 12.2 for more information.

Configuring IEEE 802.3x Flow Control

802.3x flow control enables connected Ethernet ports to control traffic rates during congestion by allowing congested nodes to pause link operation at the other end. If one port experiences congestion and cannot receive any more traffic, it notifies the other port by sending a pause frame to stop sending until the condition clears. Upon receipt of a pause frame, the sending device stops sending any data packets, which prevents any loss of data packets during the congestion period.

Note Ports can receive, but not send, pause frames.

You use the flowcontrol interface configuration command to set the interface’s ability to receive pause frames to on, off, or desired. The default state is off.

When set to desired, an interface can operate with an attached device that is required to send flow-control packets or with an attached device that is not required to but can send flow-control packets.

These rules apply to 802.3x flow control settings on the device:

• receive on (or desired): The port cannot send pause frames but can operate with an attached device that is required to or can send pause frames; the port can receive pause frames.
• receive off : 802.3x flow control does not operate in either direction. In case of congestion, no indication is given to the link partner, and no pause frames are sent or received by either device.

Note For details on the command settings and the resulting 802.3x flow control resolution on local and remote ports, see the flowcontrol interface configuration command in the Cisco IOS Interface Command Reference, Release 12.2.

Beginning in privileged EXEC mode, follow these steps to configure 802.3x flow control on an interface:

To disable 802.3x flow control, use the flowcontrol receive off interface configuration command.

This example shows how to enable 802.3x flow control on a port:

Configuring Auto-MDIX on an Interface

When automatic medium-dependent interface crossover (auto-MDIX) is enabled on an interface, the interface automatically detects the required cable connection type (straight through or crossover) and configures the connection appropriately. When connecting switches without the auto-MDIX feature, you must use straight-through cables to connect to devices such as servers, workstations, or routers and crossover cables to connect to other switches or repeaters. With auto-MDIX enabled, you can use either type of cable to connect to other devices, and the interface automatically corrects for any incorrect cabling. For more information about cabling requirements, see the hardware installation guide.

Auto-MDIX is enabled by default. When you enable auto-MDIX, you must also set the speed and duplex on the interface to auto so that the feature operates correctly. Auto-MDIX is supported on all 10/100 and 10/100/1000 Mbps interfaces and on Cisco 10/100/1000 BASE-T/TX SFP module interfaces. It is not supported on 1000 BASE-SX or -LX SFP module interfaces.

Table 8-4 shows the link states that result from auto-MDIX settings and correct and incorrect cabling.

Beginning in privileged EXEC mode, follow these steps to configure auto-MDIX on an interface:

To disable auto-MDIX, use the no mdix auto interface configuration command.

This example shows how to enable auto-MDIX on a port:

Adding a Description for an Interface

You can add a description about an interface to help you remember its function. The description appears in the output of these privileged EXEC commands: show configuration , show running-config , and show interfaces .

Beginning in privileged EXEC mode, follow these steps to add a description for an interface:

Use the no description interface configuration command to delete the description.

This example shows how to add a description on a port and how to verify the description:

Monitoring Interface Status

Commands entered at the privileged EXEC prompt display information about the interface, including the versions of the software and the hardware, the configuration, and statistics about the interfaces. Table 8-5 lists some of these interface monitoring commands. (You can display the full list of show commands by using the show ? command at the privileged EXEC prompt.) These commands are fully described in the Cisco IOS Interface Command Reference, Release 12.2.

Clearing and Resetting Interfaces and Counters

Table 8-6 lists the privileged EXEC mode clear commands that you can use to clear counters and reset interfaces.

To clear the interface counters shown by the show interfaces privileged EXEC command, use the clear counters privileged EXEC command. The clear counters command clears all current interface counters from the interface unless you specify optional arguments that clear only a specific interface type from a specific interface number.

Note The clear counters privileged EXEC command does not clear counters retrieved by using Simple Network Management Protocol (SNMP), but only those seen with the show interface privileged EXEC command.

Shutting Down and Restarting the Interface

Shutting down an interface disables all functions on the specified interface and marks the interface as unavailable on all monitoring command displays. This information is communicated to other network servers through all dynamic routing protocols. The interface is not mentioned in any routing updates.

Beginning in privileged EXEC mode, follow these steps to shut down an interface:

Use the no shutdown interface configuration command to enable an interface.

To verify that an interface is disabled, enter the show interfaces privileged EXEC command. A disabled interface is shown as administratively down in the display.