Chapter 21 Configuring Flex Links and the MAC Address-Table Move Update Feature

Configuring Flex Links and MAC Address-Table Move Update

When a Flex Link interface comes up, VLANs preferred on this interface are blocked on the peer interface and moved to the forwarding state on the interface that has just come up. In this example, if interface Gi2/0/6 comes up, VLANs preferred on this interface are blocked on the peer interface Gi2/0/8 and forwarded on Gi2/0/6.

Switch#show interfaces switchport backup

Switch Backup Interface Pairs:

Active Interface Backup Interface State

------------------------------------------------------------------------

GigabitEthernet2/0/6

GigabitEthernet2/0/8

Active Up/Backup Standby

Vlans Preferred on Active Interface: 1-50

 

 

Vlans Preferred on Backup Interface: 60,

100-120

 

Switch#show interfaces switchport backup

detail

 

Switch Backup Interface

Pairs:

 

 

Active Interface

Backup Interface

 

State

------------------------------------------------------------------------

FastEthernet1/0/3

 

FastEthernet1/0/4

Active Down/Backup Up

Vlans

Preferred on

Active Interface: 1-2,5-4094

Vlans

Preferred on

Backup Interface: 3-4

 

Preemption Mode

: off

 

Bandwidth : 10000

Kbit (Fa1/0/3), 100000

Kbit (Fa1/0/4)

Mac Address Move Update Vlan : auto

Configuring the MAC Address-Table Move Update Feature

This section contains this information:

Configuring a switch to send MAC address-table move updates

Configuring a switch to get MAC address-table move updates

Beginning in privileged EXEC mode, follow these steps to configure an access switch to send MAC address-table move updates:

 

 

Command

 

Purpose

 

Step 1

 

 

 

 

configure terminal

 

Enter global configuration mode.

 

Step 2

 

 

 

 

interface interface-id

 

Specify the interface, and enter interface configuration

 

 

 

 

mode. The interface can be a physical Layer 2 interface or

 

 

 

 

a port channel (logical interface). The port-channel range

 

 

 

 

is 1 to 48.

 

Step 3

 

 

 

 

switchport backup interface interface-id

 

Configure a physical Layer 2 interface (or port channel),

 

 

 

 

as part of a Flex Link pair with the interface. The MAC

 

 

or

 

address-table move update VLAN is the lowest VLAN ID

 

 

 

on the interface.

 

 

switchport backup interface interface-idmmu

 

Configure a physical Layer 2 interface (or port channel)

 

 

primary vlan vlan-id

 

and specify the VLAN ID on the interface, which is used

 

 

 

 

for sending the MAC address-table move update.

 

 

 

 

When one link is forwarding traffic, the other interface is

 

 

 

 

in standby mode.

 

 

 

 

 

 

 

 

 

 

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OL-9775-02

 

 

 

21-9

 

 

 

 

 

 

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Cisco Systems 3750E Configuring the MAC Address-Table Move Update Feature, Switchport backup interface interface-idmmu