Cisco Systems 3750E manual Flex Links, 21-1

C H A P T E R 21

Configuring Flex Links and the MAC

Address-Table Move Update Feature

This chapter describes how to configure Flex Links, a pair of interfaces on the Catalyst 3750-E or 3560-E switch that provide a mutual backup. It also describes how to configure the MAC address-table move update feature, also referred to as the Flex Links bidirectional fast convergence feature. Unless otherwise noted, the term switch refers to a Catalyst 3750-E or 3560-E standalone switch and to a Catalyst 3750-E switch stack.

Note For complete syntax and usage information for the commands used in this chapter, see the command reference for this release.

The chapter consists of these sections:

•Understanding Flex Links and the MAC Address-Table Move Update, page 21-1

•Configuring Flex Links and MAC Address-Table Move Update, page 21-5

•Monitoring Flex Links and the MAC Address-Table Move Update, page 21-11

Understanding Flex Links and the MAC Address-Table Move Update

This section contains this information:

•Flex Links, page 21-1

•VLAN Flex Link Load Balancing and Support, page 21-2

•MAC Address-Table Move Update, page 21-3

Flex Links

Flex Links are a pair of a Layer 2 interfaces (switch ports or port channels) where one interface is configured to act as a backup to the other. The feature provides an alternative solution to the Spanning Tree Protocol (STP). Users can disable STP and still retain basic link redundancy. Flex Links are typically configured in service provider or enterprise networks where customers do not want to run STP on the switch. If the switch is running STP, Flex Links is not necessary because STP already provides link-level redundancy or backup.

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

OL-9775-02 21-1