I Commands

This chapter describes the Cisco NX-OS routing commands that begin with I.

interface ethernet (Layer 3)

To configure a Layer 3 Ethernet IEEE 802.3 routed interface, use the interface ethernet command.

interface ethernet [ chassis_ID /] slot / port [. subintf-port-no ]

 
Syntax Description

chassis_ID

(Optional) Specifies the Fabric Extender chassis ID. The chassis ID is from 100 to 199.

Note This argument is not optional when addressing the host interfaces of a Cisco Nexus 2000 Series Fabric Extender.

slot

Slot from 1 to 3. The following list defines the slots available:

  • Slot 1 includes all the fixed ports. A Fabric Extender only has one slot.
  • 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

Port number within a particular slot. The port number is from 1 to 128.

.

(Optional) Specifies the subinterface separator.

subintf-port-no

(Optional) Port number for the subinterface. The range is from 1 to 48.

 
Command Default

None

 
Command Modes

Global configuration mode
Interface configuration mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

 
Usage Guidelines

You must use the no switchport command in the interface configuration mode to configure the interface as a Layer 3 routed interface. When you configure the interface as a Layer 3 interface, all Layer 2 specific configurations on this interface are deleted.

Use the switchport command to convert a Layer 3 interface into a Layer 2 interface. When you configure the interface as a Layer 2 interface, all Layer 3 specific configurations on this interface are deleted.

Examples

This example shows how to enter configuration mode for a Layer 3 Ethernet interface 1/5:

switch(config)# interface ethernet 1/5
switch(config-if)# no switchport
switch(config-if)# ip address 10.1.1.1/24
switch(config-if)#
 

This example shows how to enter configuration mode for a host interface on a Fabric Extender:

switch(config)# interface ethernet 101/1/1
switch(config-if)# no switchport
switch(config-if)# ip address 10.1.1.1/24
switch(config-if)#
 

This example shows how to configure a Layer 3 subinterface for Ethernet interface 1/5 in the global configuration mode:

switch(config)# interface ethernet 1/5.2
switch(config-if)# no switchport
switch(config-subif)# ip address 10.1.1.1/24
switch(config-subif)#
 

This example shows how to configure a Layer 3 subinterface in interface configuration mode:

switch(config)# interface ethernet 1/5
switch(config-if)# no switchport
switch(config-if)# interface ethernet 1/5.1
switch(config-subif)# ip address 10.1.1.1/24
switch(config-subif)#
 

This example shows how to convert a Layer 3 interface to a Layer 2 interface:

switch(config)# interface ethernet 1/5
switch(config-if)# no switchport
switch(config-if)# ip address 10.1.1.1/24
switch(config-if)# switchport
switch(config-if)#
 

 
Related Commands

Command
Description

bandwidth

Sets the bandwidth parameters for an interface.

delay

Configures the interface throughput delay value.

encapsulation

Sets the encapsulation type for an interface.

ip address

Sets a primary or secondary IP address for an interface.

inherit

Assigns a port profile to an interface.

interface vethernet

Configures a virtual Ethernet interface.

no switchport

Configures an interface as a Layer 3 interface.

service-policy

Configures a service policy for an interface.

show fex

Displays all configured Fabric Extender chassis connected to the switch.

show interface ethernet

Displays various parameters of an Ethernet IEEE 802.3 interface.

 

interface loopback

To create a loopback interface and enter interface configuration mode, use the interface loopback command. To remove a loopback interface, use the no form of this command.

interface loopback number

no interface loopback number

 
Syntax Description

number

Interface number; valid values are from 0 to 1023.

 
Command Default

None

 
Command Modes

Global configuration mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

 
Usage Guidelines

Use the interface loopback command to create or modify loopback interfaces.

From the loopback interface configuration mode, the following parameters are available:

  • description —Provides a description of the purpose of the interface.
  • ip —Configures IP features, such as the IP address for the interface, Address Resolution Protocol (ARP) attributes, load balancing, Unicast Reverse Path Forwarding (RPF) or IP Source Guard.
  • logging —Configure logging of events.
  • shutdown —Shut down traffic on the interface.

This command does not require a license.

Examples

This example shows how to create a loopback interface:

switch(config)# interface loopback 50
switch(config-if)# ip address 10.1.1.1/24
switch(config-if)#
 

 
Related Commands

Command
Description

show interface loopback

Displays information about the traffic on the specified loopback interface.

 

interface port-channel

.i.interface port-channel command;

To create an EtherChannel interface and enter interface configuration mode, use the interface port-channel command. To remove an EtherChannel interface, use the no form of this command.

interface port-channel channel-number [. subintf-channel-no ]

no interface port-channel channel-number [. subintf-channel-no ]

 
Syntax Description

channel-number

Channel number that is assigned to this EtherChannel logical interface. The range is from 1 to 4096.

.

(Optional) Specifies the subinterface separator.

Note Applies to Layer 3 interfaces.

subintf-channel-no

(Optional) Port number of the EtherChannel subinterface. The range is from 1 to 4093.

Note Applies to Layer 3 interfaces.

 
Command Default

None

 
Command Modes

Global configuration mode
Interface configuration mode

 
Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.

 
Usage Guidelines

A port can belong to only one channel group.

When you use the interface port-channel command for Layer 2 interfaces, follow these guidelines:

  • If you are using CDP, you must configure it only on the physical interface and not on the EtherChannel interface.
  • If you do not assign a static MAC address on the EtherChannel interface, a MAC address is automatically assigned. If you assign a static MAC address and then later remove it, the MAC address is automatically assigned.
  • The MAC address of the EtherChannel is the address of the first operational port added to the channel group. If this first-added port is removed from the channel, the MAC address comes from the next operational port added, if there is one.

You must use the no switchport command in the interface configuration mode to configure the EtherChannel interface as a Layer 3 interface. When you configure the interface as a Layer 3 interface, all Layer 2 specific configurations on this interface are deleted.

Use the switchport command to convert a Layer 3 EtherChannel interface into a Layer 2 interface. When you configure the interface as a Layer 2 interface, all Layer 3 specific configurations on this interface are deleted.

You can configure one or more subinterfaces on a port channel made from routed interfaces.

Examples

This example shows how to create an EtherChannel group interface with channel-group number 50:

switch(config)# interface port-channel 50
switch(config-if)#
 

This example shows how to create a Layer 3 EtherChannel group interface with channel-group number 10:

switch(config)# interface port-channel 10
switch(config-if)# no switchport
switch(config-if)# ip address 192.0.2.1/24
switch(config-if)#
 

This example shows how to configure a Layer 3 EtherChannel subinterface with channel-group number 1 in interface configuration mode:

switch(config)# interface port-channel 10
switch(config-if)# no switchport
switch(config-if)# interface port-channel 10.1
switch(config-subif)# ip address 192.0.2.2/24
switch(config-subif)#
 

This example shows how to configure a Layer 3 EtherChannel subinterface with channel-group number 20.1 in global configuration mode:

switch(config)# interface port-channel 20.1
switch(config-subif)# ip address 192.0.2.3/24
switch(config-subif)#
 

 
Related Commands

Command
Description

encapsulation

(Layer 3 interfaces) Sets the encapsulation type for an interface.

ip address

(Layer 3 interfaces) Sets a primary or secondary IP address for an interface.

no switchport

(Layer 3 interfaces) Configures an interface as a Layer 3 interface.

show interface

Displays configuration information about interfaces.

show lacp

Displays LACP information.

show port-channel summary

Displays information on the EtherChannels.

vtp (interface)

Enables VLAN Trunking Protocol (VTP) on an interface.