User Manual

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Users Manual of XGS-6350-24X4C
selected as the network root.
MSTP can set the switch to the network switch through configuration. You can run the command
Spanning-tree mstpSpanning-tree mstpinstance-idrootroot to modify the priority value of the switch in a
spanning tree instance from the default value to a sufficiently small value, ensuring the switch turns to be the
root in the spanning tree instance.
In general, after the previous command is executed, the protocol automatically check the bridge ID of the
current network root and then sets the priority field of the bridge ID to 24576 when the value 24576 ensures
that the current switch becomes the root of the spanning tree.
If the network root’s priority value is smaller than the value 24576, MSTP automatically sets the spanning
tree's priority of the current bridge to a value that is 4096 smaller than the priority value of the root. Note that
the number 4096 is a step length of network priority value.
When setting the root, you can run the diameter subcommand to the network diameter of the spanning tree
network. The keyword is effective only when the spanning tree instance ID is 0. After the network diameter is
set, MSTP automatically calculates proper STP time parameters to ensure the stability of network
convergence. Time parameters include Hello Time, Forward Delay and Maximum Age. The subcommand
Hello-time can be used to set a new hello time to replace the default settings.
Run the following command to set the switch to the network root:
Command Purpose
spanning-tree mstpinstance-idroot primary
[ diameternet-diameter
[ hello-timeseconds ] ]
Sets the switch to the root in the designated
spanning tree instance.
instance-id represents the number of the spanning
tree instance, ranging from 0 to 15.
net-diameter represents the network diameter,
which is an optional parameter. It is effective when
instance-id is 0. It ranges from 2 to 7.
seconds represents the unit of the hello time,
ranging from 1 to 10.
no spanning-tree mstpinstance-idroot
Cancels the root configuration of the switch in the
spanning tree.
instance-id means the number of the spanning tree
instance, ranging from 0 to 15.
Run the following command to check the MSTP message:
Command Purpose
show spanning-tree mstp
[ instanceinstance-id ]
Checks the MSTP message.
19.2.3.5 Configuring Secondary Root
After the network root is configured, you can run spanning-tree mstpinstance-idroot secondary to set one