Spanning-Tree Mst Pre-Standard - Cisco Catalyst 2960 Command Reference Manual

Chapter 2 Catalyst 2960 Switch Cisco IOS Commands

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).
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 Release
12.2(25)SED
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 Command
show spanning-tree
OL-8604-04
spanning-tree mst pre-standard
no spanning-tree mst pre-standard
Modification
This command was introduced.
mst instance-id
Description
Displays multiple spanning-tree (MST) information,
including the prestandard flag, for the specified interface.
Catalyst 2960 Switch Command Reference
spanning-tree mst pre-standard
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