logical-interface

Configures a logical interface on a physical port or a port-channel (LAG) on an edge port, entering LIF configuration mode, and optionally binds the interface to a bridge domain (BD).

Syntax

logical-interface { ethernet slot/port.service_instance | port-channel num.service_instance }

no logical-interface { ethernet slot/port.service_instance | port-channel num.service_instance }

Command Default

See the Usage Guidelines.

Parameters

ethernet slot/port: Specifies an Ethernet interface.
port-channel num: Specifies a port-channel interface.
service_instance: Specifies a service instance ID. Range is from 1 through 12288.

Modes

Interface subtype configuration mode

Bridge domain configuration mode

Usage Guidelines

The following are some common rules to consider in configuring logical interfaces:

This command is applicable to an edge port only.
This command by itself does not create the LIF as it requires more classifications as to what VLAN(s) should be specified and whether the classifying VLAN is untagged or tagged.
By default, when the LIF is created it is enabled. it is also "tagged" unless it is explicitly configured with the "untagged" option.
The user must specify a service instance ID. If the service instance ID has already been configured, this command allows the user to specify the VLAN classification for this LIF. Allowed LIF service instance ranges are from 1 through 12288 (12K LIFs are allowed per interface type). Currently, up to 100K LIFs are supported in the system, with 12K for physical port or LAG combined and 8K for PW based.
A LIF service instance ID has no correlation to the VLAN ID of the LIF.
Each physical/LAG-based LIF must have an associated VLAN configured or else it will not be usable when the user attempts to add it to a service. Such a configuration request to add the LIF to a service will be rejected.
Once the LIF is associated with a Layer 2 service, its VLAN value cannot be changed or deleted unless it is first removed from the associated service. In case the LIF is not yet associated to a service, the user is free to remove the VLAN configuration or change the VLAN assignment.
The "untagged" configuration can only be allowed for one LIF under the same physical port or LAG. If one LIF is already configured as untagged, all subsequent attempts on the same physical port or LAG will be rejected.
Once the "untagged" option is selected, it will only have one VLAN as the next classification option. There is no dual-tag support for the untagged case.
In order to configure an untagged LIF, the main interface must be set as "switchport mode trunk-no-default-native". If it is only set to regular trunk mode, the native VLAN is already associated with a regular Layer 2 VLAN LIF and no explicit untagged LIF can be configured on that interface.
Once the LIF is associated with a service (Layer 2) such as bridge domain, its "untagged/tagged" configuration cannot be changed. The service instance or its current VLAN classification must be deleted by user first and then added back with the proper "untagged/tagged" option.
VLANs 4091 through 4095 are reserved VLANs and these should not be used as the VLAN ID for either the inner or outer VLAN of the LIF.
The VLAN specified under the LIF ensures that such a VLAN is not already configured under the switchport command for a regular Layer 2 allowed VLAN.

The no version of the command removes the LIF from the BD configuration. This can be applied any time if the LIF is not yet associated with (bound to) a service. If it is already associated with a service, the LIF is also implicitly removed from the BD configuration.

Examples

The following example sets "trunk-no-default-native" mode on an Ethernet interface, so that an untagged LIF can be configured on service instance 120.

device(config)# interface ethernet 2/6
device(conf-if-eth-2/6)# switchport mode trunk-no-default-native
device(conf-if-eth-2/6)# logical-interface ethernet 2/6.120
device(conf-if-eth-lif-2/6.120)#

The following examples illustrate how up to command options can be configured in a single line.

device(conf-if-eth-2/6)# logical-interface ethernet 2/6.120 name myLIF120
device(conf-if-eth-lif-2/6.120)#

device(conf-if-eth-2/6)# logical-interface ethernet 2/6.120 vlan 120
device(conf-if-eth-lif-2/6.120)#

The following example sets "trunk-no-default-native" mode on a port-channel (LAG) interface, so that an untagged LIF can be configured on service instance 3.

device(config)# int port-channel 10
device(config-port-channel-10)# switchport mode trunk-no-default-native
device(config-port-channel-10)# logical-interface port-channel 10.3
device(config-if-po-lif-10.3)# untagged vlan 3

The following example shows how to create a logical Ethernet interface service instance (1/5.10) and bind it to bridge domain 4 by means of the bridge-domain command.

device# configure terminal
device(config)# interface ethernet 1/5
device(conf-if-eth-1/5)# logical-interface ethernet 1/5.10
device(conf-if-eth-lif-1/5.10)# vlan 50
device(conf-if-eth-lif-1/5.10)# exit

device(config)# bridge-domain 4
device(config-bridge-domain-4)# logical-interface ethernet 1/5.10

The following example shows how to bind a logical port-channel interface service instance (2.200) to bridge domain 4 by means of the bridge-domain command.

device# configure terminal
device(config)# bridge-domain 4
device(config-bridge-domain-4)# logical-interface port-channel 2.200

The following example shows the error message that displays when an attempt is made to bind a logical interface that was not previously created to a bridge domain.

device# configure terminal
device(config)# bridge-domain 4
device(config-bridge-domain-4)# logical-interface ethernet 1/3.100
Error: Logical Interface not yet created

The following example shows the error message that displays when an attempt is made to bind a logical interface that is previously bound to another bridge domain.

device>enable
device# configure terminal
device(config)# bridge-domain 4
device(config-bridge-domain-4)# logical-interface ethernet 1/3.100
 Error: LIF already Binded