Cisco ME 3600X, Command Reference Manual

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Cisco ME 3800X and ME 3600X Switch Command Reference
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Chapter
spanning-tree mst pre-standard
spanning-tree mst pre-standard
To configure a port to send only prestandard bridge protocol data units (BPDUs), use the spanning-tree
mst pre-standard command in interface configuration command. To return to the default setting, use
the no form of this command.
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.
You can verify your settings by entering the show spanning-tree mst privileged EXEC command.
Examples This example shows how to configure a port to send only prestandard BPDUs:
Switch(config-if)# spanning-tree mst pre-standard
Related Commands
Release Modification
12.2(52)EY 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.