multicast fast-convergence

Configures a device to listen to topology change events in Layer 2 protocols such as spanning tree, and then send general queries to shorten the convergence time.
Syntax
multicast fast-convergence
no multicast fast-convergence
Command Default

Fast convergence is not configured.

Modes

VLAN configuration mode

Usage Guidelines

The no form of this command restores the default; fast convergence is not configured.

If the Layer 2 protocol cannot detect a topology change, fast convergence may not work in some cases. For example, if the direct connection between two devices switches from one interface to another, the Rapid Spanning Tree protocol (802.1w) considers this optimization rather than a topology change. In this example, other devices do not receive topology change notifications, and cannot send queries to speed up the convergence. Fast convergence works well with the regular spanning tree protocol in this case.

Examples

The following example configures fast convergence on VLAN 70. 

device# configure terminal
device(config)# vlan 70
device(config-vlan-70)# multicast fast-convergence
Parent topic: Commands M