Configuring Ethernet Interfaces

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Updated:March 4, 2011

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Configuring Ethernet Interfaces

Contents

Configuring Ethernet Interfaces

This section describes the configuration of the Ethernet interfaces on a Cisco Nexus 5000 Series switch. It contains the following sections:

Information About Ethernet Interfaces

The Ethernet ports can operate as standard Ethernet interfaces connected to servers or to a LAN.

The Ethernet interfaces also support Fibre Channel over Ethernet (FCoE). FCoE allows the physical Ethernet link to carry both Ethernet and Fibre Channel traffic.

On a Cisco Nexus 5000 Series switch, the Ethernet interfaces are enabled by default.

About the Interface Command

You can enable the various capabilities of the Ethernet interfaces on a per-interface basis using the interface command. When you enter the interface command, you specify the following information:


  • Interface type—All physical Ethernet interfaces use the ethernet keyword.

  • Slot number


    • Slot 1 includes all the fixed ports.

    • Slot 2 includes the ports on the upper expansion module (if populated).

    • Slot 3 includes the ports on the lower expansion module (if populated).

  • Port number


    • Port number within the group.

The interface numbering convention is extended to support use with a Cisco Nexus 2000 Series Fabric Extender as follows:

switch(config)# interface ethernet [chassis/]slot/port


  • Chassis ID is an optional entry to address the ports of a connected Fabric Extender. The chassis ID is configured on a physical Ethernet or EtherChannel interface on the switch to identify the Fabric Extender discovered via the interface. The chassis ID ranges from 100 to 199.

Information About Unified Ports

Beginning in Cisco NX-OS Release 5.0(3)N1(1b), Cisco introduces unified port technology. Cisco Nexus unified ports allow you to configure a physical port on a Cisco Nexus 5500 Platform switch as a 1/10-Gigabit Ethernet, Fibre Channel over Ethernet (FCoE), or 1-, 2-, 4-, 8-Gigabit native Fibre Channel port.

Currently, most networks have two types of switches for different types of networks. For example, LAN switches carry Ethernet traffic up to Catalyst switches and SAN switches carry FC traffic from servers to MDS switches. With unified port technology, you can deploy a unified platform, unified device, and unified wire approach. Unified ports allow you to move from an existing segregated platform approach where you choose LAN and SAN port options to transition to a single, unified fabric that is transparent and consistent with existing practices and management software. A unified fabric includes the following:


  • Unified platform—Uses the same hardware platform and the same software code level and certifies it once for your LAN and SAN environments.

  • Unified device—Runs LAN and SAN services on the same platform switch. The unified device allows you to connect your Ethernet and Fibre Channel cables to the same device.

  • Unified wire—Converges LAN and SAN networks on a single converged network adapter (CNA) and connects them to your server.

A unified fabric allows you to manage Ethernet and FCoE features independently with existing Cisco tools.

The new Cisco Nexus 5548UP switch and the Cisco Nexus 5596UP switch provides built-in unified port technology. In addition, a new unified port expansion module and two Layer 3 modules increase the benefits of a deployed unified fabric. For information on the new Cisco Unified Port switches and modules, see the Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Release Notes for Cisco NX-OS Release 5.0(3)N1(1b) and NX-OS Release 5.0(3)N1(1c) and the Cisco Nexus 5000 Series Hardware Installation Guide.

About the Unidirectional Link Detection Parameter

The Cisco-proprietary Unidirectional Link Detection (UDLD) protocol allows ports that are connected through fiber optics or copper (for example, Category 5 cabling) Ethernet cables to monitor the physical configuration of the cables and detect when a unidirectional link exists. When the switch detects a unidirectional link, UDLD shuts down the affected LAN port and alerts the user. Unidirectional links can cause a variety of problems, including spanning tree topology loops.

UDLD is a Layer 2 protocol that works with the Layer 1 protocols to determine the physical status of a link. At Layer 1, autonegotiation takes care of physical signaling and fault detection. UDLD performs tasks that autonegotiation cannot perform, such as detecting the identities of neighbors and shutting down misconnected LAN ports. When you enable both autonegotiation and UDLD, Layer 1 and Layer 2 detections work together to prevent physical and logical unidirectional connections and the malfunctioning of other protocols.

A unidirectional link occurs whenever traffic transmitted by the local device over a link is received by the neighbor but traffic transmitted from the neighbor is not received by the local device. If one of the fiber strands in a pair is disconnected, as long as autonegotiation is active, the link does not stay up. In this case, the logical link is undetermined, and UDLD does not take any action. If both fibers are working normally at Layer 1, then UDLD at Layer 2 determines whether those fibers are connected correctly and whether traffic is flowing bidirectionally between the correct neighbors. This check cannot be performed by autonegotiation, because autonegotiation operates at Layer 1.

A Cisco Nexus 5000 Series switch periodically transmits UDLD frames to neighbor devices on LAN ports with UDLD enabled. If the frames are echoed back within a specific time frame and they lack a specific acknowledgment (echo), the link is flagged as unidirectional and the LAN port is shut down. Devices on both ends of the link must support UDLD in order for the protocol to successfully identify and disable unidirectional links.


Note

By default, UDLD is locally disabled on copper LAN ports to avoid sending unnecessary control traffic on this type of media.

The following figure shows an example of a unidirectional link condition. Device B successfully receives traffic from Device A on the port. However, Device A does not receive traffic from Device B on the same port. UDLD detects the problem and disables the port.

Figure 1. Unidirectional Link

Default UDLD Configuration

The following table shows the default UDLD configuration.

Table 1  UDLD Default Configuration

Feature

Default Value

UDLD global enable state

Globally disabled

UDLD aggressive mode

Disabled

UDLD per-port enable state for fiber-optic media

Enabled on all Ethernet fiber-optic LAN ports

UDLD per-port enable state for twisted-pair (copper) media

Disabled on all Ethernet 10/100 and 1000BASE-TX LAN ports

UDLD Aggressive and Nonaggressive Modes

UDLD aggressive mode is disabled by default. You can configure UDLD aggressive mode only on point-to-point links between network devices that support UDLD aggressive mode. If UDLD aggressive mode is enabled, when a port on a bidirectional link that has a UDLD neighbor relationship established stops receiving UDLD frames, UDLD tries to reestablish the connection with the neighbor. After eight failed retries, the port is disabled.

To prevent spanning tree loops, nonaggressive UDLD with the default interval of 15 seconds is fast enough to shut down a unidirectional link before a blocking port transitions to the forwarding state (with default spanning tree parameters).

When you enable the UDLD aggressive mode, the following occurs:


  • One side of a link has a port stuck (both transmission and receive)

  • One side of a link remains up while the other side of the link is down

In these cases, the UDLD aggressive mode disables one of the ports on the link, which prevents traffic from being discarded.

About Interface Speed

A Cisco Nexus 5000 Series switch has a number of fixed 10-Gigabit ports, each equipped with SFP+ interface adapters. The Cisco Nexus 5010 switch has 20 fixed ports, the first 8 of which are switchable 1-Gigabit and 10-Gigabit ports. The Cisco Nexus 5020 switch has 40 fixed ports, the first 16 of which are switchable 1-Gigabit and 10-Gigabit ports.

About the Cisco Discovery Protocol

The Cisco Discovery Protocol (CDP) is a device discovery protocol that runs over Layer 2 (the data link layer) on all Cisco-manufactured devices (routers, bridges, access servers, and switches) and allows network management applications to discover Cisco devices that are neighbors of already known devices. With CDP, network management applications can learn the device type and the Simple Network Management Protocol (SNMP) agent address of neighboring devices running lower-layer, transparent protocols. This feature enables applications to send SNMP queries to neighboring devices.

CDP runs on all media that support Subnetwork Access Protocol (SNAP). Because CDP runs over the data-link layer only, two systems that support different network-layer protocols can learn about each other.

Each CDP-configured device sends periodic messages to a multicast address, advertising at least one address at which it can receive SNMP messages. The advertisements also contain time-to-live, or holdtime information, which is the length of time a receiving device holds CDP information before discarding it. Each device also listens to the messages sent by other devices to learn about neighboring devices.

The switch supports both CDP Version 1 and Version 2.

Default CDP Configuration

The following table shows the default CDP configuration.

Table 2  Default CDP Configuration

Feature

Default Setting

CDP interface state

Enabled

CDP timer (packet update frequency)

60 seconds

CDP holdtime (before discarding)

180 seconds

CDP Version-2 advertisements

Enabled

About the Error-Disabled State

An interface is in the error-disabled (err-disabled) state when the inteface is enabled administratively (using the no shutdown command) but disabled at runtime by any process. For example, if UDLD detects a unidirectional link, the interface is shut down at runtime. However, because the interface is administratively enabled, the interface status displays as err-disabled. Once an interface goes into the err-disabled state, you must manually reenable it or you can configure an automatic timeout recovery value. The err-disabled detection is enabled by default for all causes. The automatic recovery is not configured by default.

When an interface is in the err-disabled state, use the errdisable detect cause command to find information about the error.

You can configure the automatic err-disabled recovery timeout for a particular err-disabled cause by changing the time variable.

The errdisable recovery cause command provides automatic recovery after 300 seconds. To change the recovery period, use the errdisable recovery interval command to specify the timeout period. You can specify 30 to 65535 seconds.

If you do not enable the err-disabled recovery for the cause, the interface stays in the err-disabled state until you enter the shutdown and no shutdown commands. If the recovery is enabled for a cause, the interface is brought out of the err-disabled state and allowed to retry operation once all the causes have timed out. Use the show interface status err-disabled command to display the reason behind the error.

Information About Port Profiles

Beginning with Cisco NX-OS Release 5.0(2)N1(1), you can create a port profile that contains many interface commands and apply that port profile to a range of interfaces on the Cisco Nexus 5000 Series switch. Port profiles can be applied to the following interface types:


  • Ethernet

  • VLAN network interface

  • Port channel

A command that is included in a port profile can be configured outside of the port profile. If the new configuration in the port profile conflicts with the configurations that exist outside the port profile, the commands configured for an interface in configuration terminal mode have higher priority than the commands in the port profile. If changes are made to the interface configuration after a port profile is attached to it, and the configuration conflicts with that in the port profile, the configurations in the interface will be given priority.

You inherit the port profile when you attach the port profile to an interface or range of interfaces, When you attach, or inherit, a port profile to an interface or range of interfaces, the switch applies all the commands in that port profile to the interfaces.

You can have one port profile inherit the settings from another port profile. Inheriting another port profile allows the initial port profile to assume all of the commands of the second, inherited, port profile that do not conflict with the initial port profile. Four levels of inheritance are supported. The same port profile can be inherited by any number of port profiles.

To apply the port profile configurations to the interfaces, you must enable the specific port profile. You can configure and inherit a port profile onto a range of interfaces prior to enabling the port profile; you then enable that port profile for the configurations to take effect on the specified interfaces.

When you remove a port profile from a range of interfaces, the switch undoes the configuration from the interfaces first and then removes the port profile link itself. When you remove a port profile, the switch checks the interface configuration and either skips the port profile commands that have been overridden by directly entered interface commands or returns the command to the default value.

If you want to delete a port profile that has been inherited by other port profiles, you must remove the inheritance before you can delete the port profile.

You can choose a subset of interfaces from which to remove a port profile from among that group of interfaces that you originally applied the profile. For example, if you configured a port profile and configured ten interfaces to inherit that port profile, you can remove the port profile from just some of the specified ten interfaces. The port profile continues to operate on the remaining interfaces to which it is applied.

If you delete a specific configuration for a specified range of interfaces using the interface configuration mode, that configuration is also deleted from the port profile for that range of interfaces only. For example, if you have a channel group inside a port profile and you are in the interface configuration mode and you delete that port channel, the specified port channel is also deleted from the port profile as well.

After you inherit a port profile on an interface or range of interfaces and you delete a specific configuration value, that port profile configuration will not operate on the specified interfaces.

If you attempt to apply a port profile to the wrong type of interface, the switch returns an error.

When you attempt to enable, inherit, or modify a port profile, the switch creates a checkpoint. If the port profile configuration fails, the switch rolls back to the prior configuration and returns an error. A port profile is never only partially applied.

Guidelines and Limitations

Port profiles have the following configuration guidelines and limitations:


  • Each port profile must have a unique name across interface types and the network.

  • Commands that you enter under the interface mode take precedence over the port profile’s commands if there is a conflict. However, the port profile retains that command in the port profile.

  • The port profile’s commands take precedence over the default commands on the interface, unless the default command explicitly overrides the port profile command.

  • After you inherit a port profile onto an interface or range of interfaces, you can override individual configuration values by entering the new value at the interface configuration level. If you remove the individual configuration values at the interface configuration level, the interface uses the values in the port profile again.

  • There are no default configurations associated with a port profile.

  • A subset of commands are available under the port profile configuration mode, depending on which interface type that you specify.


Note

You cannot use port profiles with Session Manager. See the Cisco Nexus 5000 Series NX-OS System Management Configuration Guide, Release 5.0(2)N1(1, for information about Session Manager.

About the Debounce Timer Parameters

The port debounce time is the amount of time that an interface waits to notify the supervisor of a link going down. During this time, the interface waits to see if the link comes back up. The wait period is a time when traffic is stopped.

You can enable the debounce timer for each interface and specify the delay time in milliseconds.


Caution

When you enable the port debounce timer the link up and link down detections are delayed, resulting in a loss of traffic during the debounce period. This situation might affect the convergence and reconvergence of some protocols.

About MTU Configuration

The Cisco Nexus 5000 Series switch is a Layer 2 device. This means it does not fragment frames. As a result, the switch cannot have two ports in the same Layer 2 domain with different maximum transmission units (MTUs). A per-physical Ethernet interface MTU is not supported. Instead, the MTU is set according to the QoS classes. You modify the MTU by setting Class and Policy maps.


Note

When you show the interface settings, a default MTU of 1500 is displayed for physical Ethernet interfaces and a receive data field size of 2112 is displayed for Fibre Channel interfaces.

Configuring Ethernet Interfaces

The section includes the following topics:

Configuring a Layer 3 Interface on a Cisco Nexus 5500 Platform Switch

Beginning with NX-OS Release 5.0(3)N1(1), on Cisco Nexus 5000 Platform switches, you can configure a Layer 3 interface.

You can change a Layer 3 interface into a Layer 2 interface by using the switchport command. You can change a Layer 2 interface into a Layer 3 interface by using the no switchport command.

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# interface ethernet slot/port

3.    switch(config-if)# no switchport

4.    switch(config-if)# no shutdown


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# interface ethernet slot/port
 

Enters configuration mode for the specified interface.

 
Step 3 switch(config-if)# no switchport
 

Selects the Layer 3 interface.

 
Step 4 switch(config-if)# no shutdown
 

Restarts the interface.

 

This example shows how to configure a Layer 3 interface: 

switch# configure terminal
switch(config)# interface ethernet 1/2
switch(config-if)# no switchport
switch(config-if)# no shutdown

Configuring Unified Ports

You can configure a unified port on a Cisco Nexus 5548UP switch, a Cisco Nexus 5596UP switch, or a Cisco Nexus 5548P switch with an installed Cisco N55-M16UP expansion module.

Unified ports allow you to configure ports as Ethernet, native Fibre Channel, or Fibre Channel over Ethernet (FCoE) ports. By default, the ports are Ethernet ports but you can change the port mode to native Fibre Channel on the following unified ports:


  • Any port on the Cisco Nexus 5548UP switch or the Cisco Nexus 5596UP switch.

  • The ports on the Cisco N55-M16UP expansion module that is installed in a Cisco Nexus 5548P switch


Note
You must configure Ethernet ports and Fibre Channel ports in a specified order:

  • Fibre Channel ports must be configured from the last port of the module.

  • Ethernet ports must be configured from the first port of the module.

If the order is not followed, the following errors are displayed: 

ERROR: Ethernet range starts from first port of the module
ERROR: FC range should end on last port of the module

On a Cisco Nexus 5548UP switch, the 32 ports of the main slot (slot1) are unified ports. The Ethernet ports start from port 1/1 to port 1/32. The Fibre Channel ports start from port 1/32 backwards to port 1/1.
SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# slot slot number

3.    switch(config-slot)# port port number type {ethernet | fc}

4.    switch(config-slot)# copy running-config startup-config

5.    switch(config-slot)# reload

6.    switch(config)# no port port number type fc


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# slot slot number
 

Identifies the slot on the switch.

 
Step 3 switch(config-slot)# port port number type {ethernet | fc}
 
Configures a unified port as a native Fibre Channel port and an Ethernet port.

  • type—Specifies the type of port to configure on a slot in a chassis.

  • ethernet—Specifies an Ethernet port.

  • fc—Specifies a Fibre Channel (FC) port.

Note   

The switch requires a reboot for changes to take effect.

 
Step 4 switch(config-slot)# copy running-config startup-config
 

Copies the running configuration to the startup configuration.

 
Step 5 switch(config-slot)# reload
 

Reboots the switch.

 
Step 6 switch(config)# no port port number type fc
 

Removes the unified port.

 

This example shows how to configure a unified port on a Cisco Nexus 5548UP switch or Cisco Nexus 5596UP switch: 

switch# configure terminal
switch(config)# slot 1
switch(config-slot)# port 32 type fc
switch(config-slot)# copy running-config startup-config
switch(config-slot)# reload

This example shows how to configure a unified port on a Cisco N55-M16UP expansion module: 

switch# configure terminal
switch(config)# slot 2
switch(config-slot)# port 32 type fc
switch(config-slot)# copy running-config startup-config
switch(config-slot)# reload

This example shows how to configure 20 ports as Ethernet ports and 12 as FC ports: 

switch# configure terminal
switch(config)# slot 1
switch(config-slot)# port 21-32 type fc
switch(config-slot)# copy running-config startup-config
switch(config-slot)# reload

Configuring the UDLD Mode

You can configure normal or aggressive unidirectional link detection (UDLD) modes for Ethernet interfaces on devices configured to run UDLD. Before you can enable a UDLD mode for an interface, you must make sure that UDLD is already enabled on the device that includes the interface. UDLD must also be enabled on the other linked interface and its device.

To use the normal UDLD mode, you must configure one of the ports for normal mode and configure the other port for the normal or aggressive mode. To use the aggressive UDLD mode, you must configure both ports for the aggressive mode.


Note

Before you begin, UDLD must be enabled for the other linked port and its device.

To configure the UDLD mode, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# feature udld

3.    switch(config)# no feature udld

4.    switch(config)# show udld global

5.    switch(config)# interface type slot/port

6.    switch(config-if)# udld {enable | disable | aggressive}

7.    switch(config-if)# show udld interface


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# feature udld
 

Enables UDLD for the device.

 
Step 3 switch(config)# no feature udld
 

Disables UDLD for the device.

 
Step 4 switch(config)# show udld global
 

Displays the UDLD status for the device.

 
Step 5 switch(config)# interface type slot/port
 

Specifies an interface to configure, and enters interface configuration mode.

 
Step 6 switch(config-if)# udld {enable | disable | aggressive}
 

Enables the normal UDLD mode, disables UDLD, or enables the aggressive UDLD mode.

 
Step 7 switch(config-if)# show udld interface
 

Displays the UDLD status for the interface.

 

This example shows how to enable the UDLD for the switch: 

 switch# configure terminal

 switch(config)# feature udld

This example shows how to enable the normal UDLD mode for an Ethernet port: 

 switch# configure terminal

 switch(config)# interface ethernet 1/4

 switch(config-if)# udld enable

This example shows how to enable the aggressive UDLD mode for an Ethernet port: 

 switch# configure terminal

 switch(config)# interface ethernet 1/4

 switch(config-if)# udld aggressive

This example shows how to disable UDLD for an Ethernet port: 

 switch# configure terminal

 switch(config)# interface ethernet 1/4

 switch(config-if)# udld disable

This example shows how to disable UDLD for the switch: 

 switch# configure terminal

 switch(config)# no feature udld

Configuring Interface Speed

The first 8 ports of a Cisco Nexus 5010 switch and the first 16 ports of a Cisco Nexus 5020 switch are switchable 1-Gigabit and 10-Gigabit ports. The default interface speed is 10-Gigabit. To configure these ports for 1-Gigabit Ethernet, insert a 1-Gigabit Ethernet SFP transceiver into the applicable port and then set its speed with the speed command.

To configure a 1-Gigabit Ethernet port, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# interface type slot/port

3.    switch(config-if)# speed speed


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# interface type slot/port
 

Enters interface configuration mode for the specified interface. This interface must have a 1-Gigabit Ethernet SFP transceiver inserted into it.

 
Step 3 switch(config-if)# speed speed
 

Sets the speed on the interface.

 

The following example shows how to set the speed for a 1-Gigabit Ethernet port: 

switch# configure terminal

switch(config)# interface ethernet 1/4

switch(config-if)# speed 1000

This command can only be applied to a physical Ethernet interface.


Note

If the interface and transceiver speed is mismatched, the SFP validation failed message is displayed when you enter the show interface ethernet slot/port command. For example, if you insert a 1-Gigabit SFP transceiver into a port without configuring the speed 1000 command, you will get this error. By default, all ports are 10 Gigabits.

Configuring the CDP Characteristics

You can configure the frequency of Cisco Discovery Protocol (CDP) updates, the amount of time to hold the information before discarding it, and whether or not to send Version-2 advertisements.

To configure CDP characteristics for an interface, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    (Optional) switch(config)# [no] cdp advertise {v1 | v2 }

3.    (Optional) switch(config)# [no] cdp format device-id {mac-address | serial-number | system-name}

4.    (Optional) switch(config)# [no] cdp holdtime seconds

5.    (Optional) switch(config)# [no] cdp timer seconds


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# [no] cdp advertise {v1 | v2 }
  		(Optional)

Configures the version to use to send CDP advertisements. Version-2 is the default state.

Use the no form of the command to return to its default setting.

 
Step 3 switch(config)# [no] cdp format device-id {mac-address | serial-number | system-name}
  		(Optional)

Configures the format of the CDP device ID. The default is the system name, which can be expressed as a fully qualified domain name.

Use the no form of the command to return to its default setting.

 
Step 4 switch(config)# [no] cdp holdtime seconds
  		(Optional)

Specifies the amount of time a receiving device should hold the information sent by your device before discarding it. The range is 10 to 255 seconds; the default is 180 seconds.

Use the no form of the command to return to its default setting.

 
Step 5 switch(config)# [no] cdp timer seconds
  		(Optional)

Sets the transmission frequency of CDP updates in seconds. The range is 5 to 254; the default is 60 seconds.

Use the no form of the command to return to its default setting.

 

This example shows how to configure CDP characteristics: 

switch# configure terminal

switch(config)# cdp timer 50

switch(config)# cdp holdtime 120

switch(config)# cdp advertise v2

Enabling or Disabling CDP

You can enable or disable CDP for Ethernet interfaces. This protocol works only when you have it enabled on both interfaces on the same link.

To enable or disable CDP for an interface, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# interface type slot/port

3.    switch(config-if)# cdp enable

4.    switch(config-if)# no cdp enable


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# interface type slot/port
 

Enters interface configuration mode for the specified interface.

 
Step 3 switch(config-if)# cdp enable
 

Enables CDP for the interface.

To work correctly, this parameter must be enabled for both interfaces on the same link.

 
Step 4 switch(config-if)# no cdp enable
 

Disables CDP for the interface.

 

The following example shows how to enable CDP for an Ethernet port: 

switch# configure terminal

switch(config)# interface ethernet 1/4

switch(config-if)# cdp enable

This command can only be applied to a physical Ethernet interface.

Enabling the Error-Disabled Detection

You can enable error-disable (err-disabled) detection in an application. As a result, when a cause is detected on an interface, the interface is placed in an err-disabled state, which is an operational state that is similar to the link-down state.

SUMMARY STEPS

1.    config t

2.    errdisable detect cause {all | link-flap | loopback}

3.    shutdown

4.    no shutdown

5.    show interface status err-disabled

6.    copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 config t


Example: 
switch# config t
switch(config)#
 

Enters configuration mode.

 
Step 2 errdisable detect cause {all | link-flap | loopback}


Example: 
switch(config)# errdisable detect cause all
switch(config)#
 

Specifies a condition under which to place the interface in an err-disabled state. The default is enabled.

 
Step 3 shutdown


Example: 
switch(config)# shutdown
switch(config)#
 

Brings the interface down administratively. To manually recover the interface from the err-disabled state, enter this command first.

 
Step 4 no shutdown


Example: 
switch(config)# no shutdown
switch(config)#
 

Brings the interface up administratively and enables the interface to recover manually from the err-disabled state.

 
Step 5 show interface status err-disabled


Example: 
switch(config)# show interface status err-disabled
 

Displays information about err-disabled interfaces.

 
Step 6 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
 

(Optional) Copies the running configuration to the startup configuration.

 

This example shows how to enable the err-disabled detection in all cases:

switch(config)#errdisable detect cause all
switch(config)#

Enabling the Error-Disabled Recovery

You can specify the application to bring the interface out of the error-disabled (err-disabled) state and retry coming up. It retries after 300 seconds, unless you configure the recovery timer (see the errdisable recovery interval command).

SUMMARY STEPS

1.    config t

2.    errdisable recovery cause {all | udld | bpduguard | link-flap | failed-port-state | pause-rate-limit}

3.    show interface status err-disabled

4.    copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 config t


Example: 
switch#config t
switch(config)#
 

Enters configuration mode.

 
Step 2 errdisable recovery cause {all | udld | bpduguard | link-flap | failed-port-state | pause-rate-limit}


Example: 
switch(config)#errdisable recovery cause all
switch(config-if)#
 

Specifies a condition under which the interface automatically recovers from the err-disabled state, and the device retries bringing the interface up. The device waits 300 seconds to retry. The default is disabled.

 
Step 3 show interface status err-disabled


Example: 
switch(config)#show interface status err-disabled
 

Displays information about err-disabled interfaces.

 
Step 4 copy running-config startup-config


Example: 
switch(config)#copy running-config startup-config
 

(Optional) Copies the running configuration to the startup configuration.

 

This example shows how to enable err-disabled recovery under all conditions:

switch(config)#errdisable recovery cause all
switch(config)#

Configuring the Error-Disabled Recovery Interval

You can use this procedure to configure the err-disabled recovery timer value. The range is from 30 to 65535 seconds. The default is 300 seconds.

SUMMARY STEPS

1.    config t

2.    errdisable recovery interval interval

3.    show interface status err-disabled

4.    copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 config t


Example: 
switch#config t
switch(config)#
 

Enters configuration mode.

 
Step 2 errdisable recovery interval interval


Example: 
switch(config)#errdisable recovery interval 32
switch(config-if)#
 

Specifies the interval for the interface to recover from the err-disabled state. The range is from 30 to 65535 seconds. The default is 300 seconds.

 
Step 3 show interface status err-disabled


Example: 
switch(config)#show interface status err-disabled
 

Displays information about err-disabled interfaces.

 
Step 4 copy running-config startup-config


Example: 
switch(config)#copy running-config startup-config
 

(Optional) Copies the running configuration to the startup configuration.

 

This example shows how to enable err-disabled recovery under all conditions:

switch(config)#errdisable recovery cause all
switch(config)#

Configuring Port Profiles

You can apply several configuration parameters to a range of interfaces simultaneously. All the interfaces in the range must be the same type. You can also inherit the configurations from one port profile into another port profile. The switch supports four levels of inheritance.

This section includes the following topics:

Creating a Port Profile

You can create a port profile on the switch. Each port profile must have a unique name across interface types and the network.

SUMMARY STEPS

1.    configure terminal

2.    port-profile [type {ethernet | interface-vlan | port channel}] name

3.    exit

4.    (Optional) show port-profile

5.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 port-profile [type {ethernet | interface-vlan | port channel}] name


Example: 
switch(config)# port-profile type ethernet test
switch(config-port-prof)#
 

Creates and names a port profile for the specified type of interface and enters the port profile configuration mode.

 
Step 3 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits port profile configuration mode.

 
Step 4 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 5 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how to create a port profile named test for Ethernet interfaces:

switch# configure terminal 
switch(config)# port-profile type ethernet test
switch(config-port-prof)#

This example shows how to add the interface commands to a port profile named ppEth configured for Ethernet interfaces:

switch# configure terminal
switch(config)# port-profile ppEth
switch(config-port-prof)# switchport mode trunk
switch(config-port-prof)# switchport trunk allowed vlan 300-400
switch(config-port-prof)# flowcontrol receive on
switch(config-port-prof)# speed 10000
switch(config-port-prof)#

Modifying a Port Profile

You can modify a port profile in port-profile configuration mode.

You can remove commands from a port profile using the no form of the command. When you remove a command from the port profile, the corresponding command is removed from the interface that is attached to the port profile.

SUMMARY STEPS

1.    configure terminal

2.    port-profile [type {ethernet | interface-vlan | port channel}] name

3.    exit

4.    (Optional) show port-profile

5.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 port-profile [type {ethernet | interface-vlan | port channel}] name


Example: 
switch(config)# port-profile type ethernet test
switch(config-port-prof)#
 

Enters the port profile configuration mode for the specified port profile and allows you to add or remove configurations to the profile.

 
Step 3 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits the port profile configuration mode.

 
Step 4 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 5 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how to remove commands from the port profile named ppEth configured for an Ethernet interface:

switch# configure terminal
switch(config)# port-profile ppEth
switch(config-port-prof)# switchport mode trunk
switch(config-port-prof)# switchport trunk allowed vlan 300-400
switch(config-port-prof)# flowcontrol receive on
switch(config-port-prof)# no speed 10000
switch(config-port-prof)#

Enabling a Specific Port Profile

SUMMARY STEPS

1.    configure terminal

2.    port-profile [type {ethernet | interface-vlan | port channel}] name

3.    state enabled name

4.    exit

5.    (Optional) show port-profile

6.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 port-profile [type {ethernet | interface-vlan | port channel}] name


Example: 
switch(config)# port-profile type ethernet test
switch(config-port-prof)# no shutdown
switch(config-port-prof)#
 

Enters the port profile configuration mode for the specified port profile.

 
Step 3 state enabled name


Example: 
switch(config-port-prof)# state enabled
switch(config-port-prof)#
 

Enables the port profile.

 
Step 4 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits the port profile configuration mode.

 
Step 5 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 6 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how to enter port profile configuration mode and enable the port profile:

switch# configure terminal 
switch(config)# port-profile type ethernet test
switch(config-port-prof)# state enabled
switch(config-port-prof)#

Inheriting a Port Profile

You can inherit a port profile onto an existing port profile. The switch supports four levels of inheritance.

SUMMARY STEPS

1.    configure terminal

2.    port-profile name

3.    inherit port-profile name

4.    exit

5.    (Optional) show port-profile

6.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 port-profile name


Example: 
switch(config)# port-profile test
switch(config-port-prof)#
 

Enters port profile configuration mode for the specified port profile.

 
Step 3 inherit port-profile name


Example: 
switch(config-port-prof)#  inherit port-profile adam
switch(config-port-prof)#
 

Inherits another port profile onto the existing one. The original port profile assumes all the configurations of the inherited port profile.

 
Step 4 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits the port profile configuration mode.

 
Step 5 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 6 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how to inherit the port profile named adam onto the port profile named test:

switch# configure terminal 
switch(config)# port-profile test
switch(config-ppm)# inherit port-profile adam
switch(config-ppm)#

This example shows how to add the interface commands to a port profile named ppEth configured for Ethernet interfaces:

switch# configure terminal
switch(config)# port-profile ppEth
switch(config-port-prof)# switchport mode trunk
switch(config-port-prof)# switchport trunk allowed vlan 300-400
switch(config-port-prof)# flowcontrol receive on
switch(config-port-prof)# speed 10000
switch(config-port-prof)#

This example shows how to inherit a port profile named ppEth configured for Ethernet interfaces into an existing port profile named test:

switch# configure terminal
switch(config)# port-profile test
switch(config-port-prof)# inherit port-profile ppEth
switch(config-port-prof)#

This example shows how to assign a port profile named ppEth configured for Ethernet interfaces to a range of Ethernet interfaces:

switch# configure terminal
switch(config)# interface ethernet 1/2-5
switch(config-if)# inherit port-profile ppEth
switch(config-if)#

This example shows how to remove an inherited port profile named ppEth from an existing port profile named test:

switch# configure terminal
switch(config)# port-profile test
switch(config-port-prof)# no inherit port-profile ppEth
switch(config-port-prof)#

Removing an Inherited Port Profile

You can remove an inherited port profile.

SUMMARY STEPS

1.    configure terminal

2.    port-profile name

3.    no inherit port-profile name

4.    exit

5.    (Optional) show port-profile

6.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 port-profile name


Example: 
switch(config)# port-profile test
switch(config-port-prof)#
 

Enters port profile configuration mode for the specified port profile.

 
Step 3 no inherit port-profile name


Example: 
switch(config-port-prof)#  no inherit port-profile adam
switch(config-port-prof)#
 

Removes an inherited port profile from this port profile.

 
Step 4 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits the port profile configuration mode.

 
Step 5 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 6 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how to remove the inherited port profile named adam from the port profile named test:

switch# configure terminal 
switch(config)# port-profile test
switch(config-ppm)# no inherit port-profile adam
switch(config-ppm)#

Assigning a Port Profile to a Range of Interfaces

You can assign a port profile to an interface or to a range of interfaces. All of the interfaces must be the same type.

SUMMARY STEPS

1.    configure terminal

2.    interface [ethernet slot/port | interface-vlan vlan-id | port-channel number]

3.    inherit port-profile name

4.    exit

5.    (Optional) show port-profile

6.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 interface [ethernet slot/port | interface-vlan vlan-id | port-channel number]


Example: 
switch(config)# interface ethernet 7/3-5, 10/2, 11/20-25
switch(config-if)#
 

Selects the range of interfaces.

 
Step 3 inherit port-profile name


Example: 
switch(config-if)# inherit port-profile adam
switch(config-if)#
 

Assigns the specified port profile to the selected interfaces.

 
Step 4 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits port profile configuration mode.

 
Step 5 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 6 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how to assign the port profile named adam to Ethernet interfaces 2/3 to 2/5, 3/2, and 1/20 to 1/25:

switch# configure terminal 
switch(config)# interface ethernet 2/3 to 2/5, 3/2, and 1/20 to 1/25
switch(config-if)# inherit port-profile adam
switch(config-if)#

Removing a Port Profile from a Range of Interfaces

You can remove a port profile from some or all of the interfaces to which you have applied the profile.

SUMMARY STEPS

1.    configure terminal

2.    interface [ethernet slot/port | interface-vlan vlan-id | port-channel number]

3.    no inherit port-profile name

4.    exit

5.    (Optional) show port-profile

6.    (Optional) copy running-config startup-config


DETAILED STEPS
  Command or Action Purpose
Step 1 configure terminal


Example: 
switch# configure terminal
switch(config)#
 

Enters configuration mode.

 
Step 2 interface [ethernet slot/port | interface-vlan vlan-id | port-channel number]


Example: 
switch(config)# interface ethernet 7/3-5, 10/2, 11/20-25
switch(config-if)#
 

Selects the range of interfaces.

 
Step 3 no inherit port-profile name


Example: 
switch(config-if)# no inherit port-profile adam
switch(config-if)#
 

Removes the specified port profile from the selected interfaces.

 
Step 4 exit


Example: 
switch(config-port-prof)# exit
switch(config)#
 

Exits port profile configuration mode.

 
Step 5 show port-profile


Example: 
switch(config)# show port-profile name
  		(Optional)

Displays the port profile configuration.

 
Step 6 copy running-config startup-config


Example: 
switch(config)# copy running-config startup-config
  		(Optional)

Copies the running configuration to the startup configuration.

 

This example shows how tos remove the port profile named adam from Ethernet interfaces 1/3-5:

switch# configure terminal 
switch(config)# interface ethernet 1/3-5
switch(config-if)# no inherit port-profile adam
switch(config-if)#

Configuration Examples for Port Profiles

The following example shows how to configure a port profile, inherit the port profile on an Ethernet interface, and enabling the port profile.

switch(config)#
switch(config)# show running-config interface Ethernet1/14
 
!Command: show running-config interface Ethernet1/14
!Time: Thu Aug 26 07:01:32 2010
 
version 5.0(2)N1(1)
 
interface Ethernet1/14
 
switch(config)# port-profile type ethernet alpha
switch(config-port-prof)# switchport mode trunk
switch(config-port-prof)# switchport trunk allowed vlan 10-15
switch(config-port-prof)#
switch(config-port-prof)# show running-config port-profile alpha
 
!Command: show running-config port-profile alpha
!Time: Thu Aug 26 07:02:29 2010
 
version 5.0(2)N1(1)
port-profile type ethernet alpha
  switchport mode trunk
  switchport trunk allowed vlan 10-15
 

switch(config-port-prof)# int eth 1/14
switch(config-if)# inherit port-profile alpha
switch(config-if)#
switch(config-if)# port-profile type ethernet alpha
switch(config-port-prof)# state enabled
switch(config-port-prof)#
switch(config-port-prof)# sh running-config interface ethernet 1/14
 
!Command: show running-config interface Ethernet1/14
!Time: Thu Aug 26 07:03:17 2010
 
version 5.0(2)N1(1)
 
interface Ethernet1/14
  inherit port-profile alpha
 
switch(config-port-prof)# sh running-config interface ethernet 1/14 expand-port-profile
 
!Command: show running-config interface Ethernet1/14 expand-port-profile
!Time: Thu Aug 26 07:03:21 2010
 
version 5.0(2)N1(1)
 
interface Ethernet1/14
  switchport mode trunk
  switchport trunk allowed vlan 10-15
 
switch(config-port-prof)#

Configuring the Debounce Timer

You can enable the debounce timer for Ethernet ports by specifying a debounce time (in milliseconds) or disable the timer by specifying a debounce time of 0.

You can show the debounce times for all of the Ethernet ports by using the show interface debounce command.

To enable or disable the debounce timer, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# interface type slot/port

3.    switch(config-if)# link debounce time milliseconds


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# interface type slot/port
 

Enters interface configuration mode for the specified interface.

 
Step 3 switch(config-if)# link debounce time milliseconds
 

Enables the debounce timer for the amount of time (1 to 5000 milliseconds) specified.

Disables the debounce timer if you specify 0 milliseconds.

 

This example shows how to enable the debounce timer and set the debounce time to 1000 milliseconds for an Ethernet interface: 

switch# configure terminal

switch(config)# interface ethernet 1/4

switch(config-if)# link debounce time 1000

This example shows how to disable the debounce timer for an Ethernet interface: 

switch# configure terminal

switch(config)# interface ethernet 1/4

switch(config-if)# link debounce time 0

This command can only be applied to a physical Ethernet interface.

Configuring the Description Parameter

To provide textual interface descriptions for the Ethernet ports, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# interface type slot/port

3.    switch(config-if)# description test


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# interface type slot/port
 

Enters interface configuration mode for the specified interface.

 
Step 3 switch(config-if)# description test
 

Specifies the description for the interface.

 

This example shows how to set the interface description to "Server 3 Interface." 

switch# configure terminal

switch(config)# interface ethernet 1/3

switch(config-if)# description Server 3 Interface

Disabling and Restarting Ethernet Interfaces

You can shut down and restart an Ethernet interface. This action disables all of the interface functions and marks the interface as being down on all monitoring displays. This information is communicated to other network servers through all dynamic routing protocols. When shut down, the interface is not included in any routing updates.

To disable an interface, perform this task:

SUMMARY STEPS

1.    switch# configure terminal

2.    switch(config)# interface type slot/port

3.    switch(config-if)# shutdown

4.    switch(config-if)# no shutdown


DETAILED STEPS
  Command or Action Purpose
Step 1 switch# configure terminal
 

Enters configuration mode.

 
Step 2 switch(config)# interface type slot/port
 

Enters interface configuration mode for the specified interface.

 
Step 3 switch(config-if)# shutdown
 

Disables the interface.

 
Step 4 switch(config-if)# no shutdown
 

Restarts the interface.

 

The following example shows how to disable an Ethernet port: 

switch# configure terminal

switch(config)# interface ethernet 1/4

switch(config-if)# shutdown

The following example shows how to restart an Ethernet interface: 

switch# configure terminal

switch(config)# interface ethernet 1/4

switch(config-if)# no shutdown

Displaying Interface Information

To view configuration information about the defined interfaces, perform one of these tasks:

Command

Purpose

switch# show interface type slot/port

Displays the detailed configuration of the specified interface.

switch# show interface type slot/port capabilities

Displays detailed information about the capabilities of the specified interface. This option is only available for physical interfaces

switch# show interface type slot/port transceiver

Displays detailed information about the transceiver connected to the specified interface. This option is only available for physical interfaces.

switch# show interface brief

Displays the status of all interfaces.

switch# show interface debounce

Displays the debounce status of all interfaces.

switch# show interface flowcontrol

Displays the detailed listing of the flow control settings on all interfaces.

show port--profile

Displays information about the port profiles.

The show interface command is invoked from EXEC mode and displays the interface configurations. Without any arguments, this command displays the information for all the configured interfaces in the switch.

The following example shows how to display the physical Ethernet interface: 

switch# show interface ethernet 1/1
Ethernet1/1 is up
  Hardware is 1000/10000 Ethernet, address is 000d.eca3.5f08 (bia 000d.eca3.5f08)
  MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 190/255, rxload 192/255
  Encapsulation ARPA
  Port mode is trunk
  full-duplex, 10 Gb/s, media type is 1/10g
  Input flow-control is off, output flow-control is off
  Auto-mdix is turned on
  Rate mode is dedicated
  Switchport monitor is off
  Last clearing of "show interface" counters never
  5 minute input rate 942201806 bytes/sec, 14721892 packets/sec
  5 minute output rate 935840313 bytes/sec, 14622492 packets/sec
  Rx
    129141483840 input packets 0 unicast packets 129141483847 multicast packets
    0 broadcast packets 0 jumbo packets 0 storm suppression packets
    8265054965824 bytes
    0 No buffer 0 runt 0 Overrun
    0 crc 0 Ignored 0 Bad etype drop
    0 Bad proto drop
  Tx
    119038487241 output packets 119038487245 multicast packets
    0 broadcast packets 0 jumbo packets
    7618463256471 bytes
    0 output CRC 0 ecc
    0 underrun 0 if down drop     0 output error 0 collision 0 deferred
    0 late collision 0 lost carrier 0 no carrier
    0 babble
    0 Rx pause 8031547972 Tx pause 0 reset

The following example shows how to display the physical Ethernet capabilities: 

switch# show interface ethernet 1/1 capabilities
Ethernet1/1
  Model:                 734510033
  Type:                  10Gbase-(unknown)
  Speed:                 1000,10000
  Duplex:                full
  Trunk encap. type:     802.1Q
  Channel:               yes
  Broadcast suppression: percentage(0-100)
  Flowcontrol:           rx-(off/on),tx-(off/on)
  Rate mode:             none
  QOS scheduling:        rx-(6q1t),tx-(1p6q0t)
  CoS rewrite:           no
  ToS rewrite:           no
  SPAN:                  yes
  UDLD:                  yes
  Link Debounce:         yes
  Link Debounce Time:    yes
  MDIX:                  no
  FEX Fabric:            yes

The following example shows how to display the physical Ethernet transceiver: 

switch# show interface ethernet 1/1 transceiver
Ethernet1/1
    sfp is present
    name is CISCO-EXCELIGHT
    part number is SPP5101SR-C1
    revision is A
    serial number is ECL120901AV
    nominal bitrate is 10300 MBits/sec
    Link length supported for 50/125mm fiber is 82 m(s)
    Link length supported for 62.5/125mm fiber is 26 m(s)
    cisco id is --
    cisco extended id number is 4

The following example shows how to display a brief interface status (some of the output has been removed for brevity): 

switch# show interface brief
 
--------------------------------------------------------------------------------
Ethernet      VLAN   Type Mode   Status  Reason                   Speed     Port
Interface                                                                   Ch #
--------------------------------------------------------------------------------
Eth1/1        200    eth  trunk  up      none                        10G(D) --
Eth1/2        1      eth  trunk  up      none                        10G(D) --
Eth1/3        300    eth  access down    SFP not inserted            10G(D) --
Eth1/4        300    eth  access down    SFP not inserted            10G(D) --
Eth1/5        300    eth  access down    Link not connected         1000(D) --
Eth1/6        20     eth  access down    Link not connected          10G(D) --
Eth1/7        300    eth  access down    SFP not inserted            10G(D) --
...

The following example shows how to display the link debounce status (some of the output has been removed for brevity): 

switch# show interface debounce
 
--------------------------------------------------------------------------------
Port          Debounce time   Value(ms)
--------------------------------------------------------------------------------
...
Eth1/1        enable               100
Eth1/2        enable               100
Eth1/3        enable               100
...

The following example shows how to display the CDP neighbors: 

switch# show cdp neighbors
Capability Codes: R - Router, T - Trans-Bridge, B - Source-Route-Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater,
                  V - VoIP-Phone, D - Remotely-Managed-Device,
                  s - Supports-STP-Dispute
 
 
Device ID              Local Intrfce   Hldtme  Capability  Platform      Port ID
 
d13-dist-1               mgmt0           148     S I      WS-C2960-24TC  Fas0/9
n5k(FLC12080012)         Eth1/5          8       S I s    N5K-C5020P-BA  Eth1/5

Note

From Cisco NX-OS Release 4.0(1a)N1(1), the default value of the device ID field for CDP advertisement has been changed from the chassis serial number to the hostname and serial number, as in the example above.

Default Physical Ethernet Settings

The following table lists the default settings for all physical Ethernet interfaces:

Parameter

Default Setting

Debounce

Enable, 100 milliseconds

Duplex

Auto (full-duplex)

Encapsulation

ARPA

MTU1

1500 bytes

Port Mode

Access

Speed

Auto (10000)

1 MTU cannot be changed per-physical Ethernet interface. You modify MTU by selecting maps of QoS classes.

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