Cisco Catalyst 3750-X Command Reference

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Catalyst 3750-X and 3560-X Switch Command Reference
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Chapter 2 Catalyst 3750-X and 3560-X Switch Cisco IOS Commands
spanning-tree mst pre-standard
spanning-tree mst pre-standard
Use the spanning-tree mst pre-standard interface configuration command to configure a port to send
only prestandard bridge protocol data units (BPDUs).
spanning-tree mst pre-standard
no spanning-tree mst pre-standard
Syntax Description This command has no arguments or keywords.
Command Default The default state is automatic detection of prestandard neighbors.
Command Modes Interface configuration
Command History
Usage Guidelines The port can accept both prestandard and standard BPDUs. If the neighbor types are mismatched, only
the common and internal spanning tree (CIST) runs on this interface.
Note If a switch port is connected to a switch running prestandard Cisco IOS software, you must use the
spanning-tree mst pre-standard interface configuration command on the port. If you do not configure
the port to send only prestandard BPDUs, the Multiple STP (MSTP) performance might diminish.
When the port is configured to automatically detect prestandard neighbors, the prestandard flag always
appears in the show spanning-tree mst commands.
Examples This example shows how to configure a port to send only prestandard BPDUs:
Switch(config-if)# spanning-tree mst pre-standard
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Related Commands
Release Modification
12.2(53)SE2 This command was introduced.
Command Description
show spanning-tree mst instance-id Displays multiple spanning-tree (MST) information,
including the prestandard flag, for the specified interface.

Cisco Catalyst 3750-X Specifications

General

Brand	Cisco
Model	Catalyst 3750-X
Category	Switch
Language	English