Cisco 4500M Command Reference

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Catalyst4500 Series SwitchCiscoIOS Command Reference—Release 12.2(18)EW
78-16201-01
Chapter2Cisco IOS Commands for the Catalyst 4500 Series Switches
spanning-tree extend system-id
spanning-tree extend system-id
To enable the extended system ID feature on a chassis that supports 1024 MAC addresses, use the
spanning-tree extend system-id command. To disable the feature, use the no form of this command.
spanning-tree extend system-id
no spanning-tree extend system-id
Syntax Description This command has no arguments or keywords.
Defaults Enabled on systems that do not provide 1024 MAC addresses.
Command Modes Global configuration
Command History
Usage Guidelines Releases 12.1(13)E and later support chassis with 64 or 1024 MAC addresses. For chassis with 64 MAC
addresses, STP uses the extended system ID plus a MAC address to make the bridge ID unique for each
VLAN.
You cannot disable the extended system ID on chassis that support 64 MAC addresses.
Enabling or disabling the extended system ID updates the bridge IDs of all active STP instances, which
might change the spanning tree topology.
Examples This example shows how to enable the extended system ID:
Switch(config)# spanning-tree extend system-id
Switch(config)#
Related Commands show spanning-tree
Release Modification
12.1(12c)EW Support for this command was introduced on the Catalyst 4500 series switch.

Cisco 4500M Specifications

General

Brand	Cisco
Model	4500M
Category	Network Router
Language	English