PLANET XGS3-24042 - Manual (Page 267)

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priority. The valid range is from 0 to 61440. The value should be the multiples of 4096, such as 0,
4096, 8192…61440.
Command mode:
Global Mode
Default:
The default bridge priority is 32768.
Usage Guide:
By setting the bridge priority, users can change the bridge ID for the specified instance. And the
bridge ID can influence the elections of root bridge and designated port for the specified instance.
Example:
Set the priority for Instance 2 to 4096.
Switch(config)#spanning-tree mst 2 priority 4096
14.1.24 spanning-tree mst rootguard
Command:
spanning-tree [mst <instance-id>] rootguard
no spanning-tree [mst <instance-id>] rootguard
Function:
Enable the rootguard function for specified instance, the rootguard function forbid the port to be
MSTP root port. “no spanning-tree mst <instance-id> rootguard” disable the rootguard function.
Parameter:
<instance-id>：MSTP instance ID.
Command mode:
Port Mode.
Default:
Disable rootguard function.
Usage Guide:
The command is used in Port Mode, if the port is configured to be a rootguand port, it is forbidden to
be a MSTP root port. If superior BPDU packet is received from a rootguard port, MSTP did not
recalculate spanning-tree, and just set the status of the port to be root_inconsistent (blocked).If no
superior BPDU packet is received from a blocked rootguard port, the port status will restore to be
forwarding. The rootguard function can maintain a relative stable spanning-tree topology when a
new switch is added to the network.
Example:
Enable rootguard function for port 1/0/2 in instance 0.