Command Reference Guide

SROS Command Line Interface Reference Guide PPP Interface Configuration Command Set

bridge-group <group#> spanning-disabled

Use the bridge-group spanning-disabled command to transparently bridge two interfaces on a network

(that have no parallel or redundant paths) without the overhead of spanning-tree protocol calculations. To

enable the spanning-tree protocol on an interface, use the no form of this command.

Syntax Description

<group#> Bridge group number (1 to 255) specified using the bridge-group command

Default Values

By default, spanning-tree protocol is enabled on all created bridge groups.

Command Modes

(config-interface)# Interface Configuration Mode

Valid interfaces include: Ethernet (eth 0/1), virtual PPP interfaces (ppp 1), and

virtual Frame Relay interfaces (fr 1).

Functional Notes

When no parallel (redundant) paths exist within a bridged network, disabling the spanning tree protocol

reduces traffic on the bridged interface. This traffic reduction can be helpful when bridging over a WAN link.

Usage Examples

The following example disables the spanning-tree protocol for bridge group 17 on the PPP interface

labeled 1:

(config)#interface ppp 1

(config-ppp 1)#bridge-group 17 spanning-disabled

Technology Review

Spanning-tree protocol provides a way to prevent loopback or parallel paths in bridged networks. Using the

priority values and path costs assigned to each bridging interface, the spanning-tree protocol determines

the root path and identifies whether to block or allow other paths.

Note

Before disabling the spanning-tree protocol on a bridged interface, verify that no redundant

loops exist.