Multiple Instance
Configuring MSTP
Syntax:
MSTP uses this parameter to determine the port(s) to use for forwarding. The port with the lowest priority number has the highest priority for use. The range is 0 to 240, and is configured by specifying a multiplier from 0 - 15. When you specify a priority multiplier of 0 - 15, the actual priority assigned to the switch is:
For example, if you configure “2” as the priority multiplier on a given port, then the actual Priority setting is 32. Thus, after you specify the port priority multiplier, the switch displays the actual port priority (and not the multiplier) in the show
You can view the actual multiplier setting for ports by executing show running and looking for an entry in this format:
For example, configuring port A2 with a priority multiplier of “3” results in this line in the show running output:
Syntax:
MSTP only. When a port is enabled as
The superior BPDUs received on a port enabled as root- guard are ignored. All other BPDUs are accepted and the external devices may belong to the spanning tree as long as they do not claim to be the Root device.
Use this command on MSTP switch ports that are connected to devices located in other administrative network domains to:
•Ensure the stability of the core MSTP network topology so that undesired or damaging influences external to the network do not enter.
•Protect the configuration of the CIST root bridge that serves as the common root for the entire network.
Default: Disabled.