Configure The Bridge Priority For A Switch; Configure The Max Hops In An Mst Region - Huawei Quidway S3500 Series Operation Manual

Operation Manual - STP
Quidway S3500 Series Ethernet Switches
Generally, if there is STP switch on the switching network, the port connected to it will
automatically transit from MSTP mode to STP-compatible mode. But the port cannot
automatically transit back to MSTP mode after the STP switch is removed.
By default, MSTP runs in MSTP mode.

1.2.4 Configure the Bridge Priority for a Switch

Whether a switch can be elected as the spanning tree root depends on its Bridge
priority. The switch configured with a smaller Bridge priority is more likely to become the
root. An MSTP switch may have different priorities in different STIs.
You can use the following command to configure the Bridge priorities of the designated
switch in different STIs.
Perform the following configuration in system view.
Table 1-6 Configure the Bridge priority for a switch
Configure the Bridge priority of the
designated switch.
Restore the default Bridge priority of the
designated switch.
When configuring the switch priority with the instance instance-id parameter as 0, you
are configuring the CIST priority of the switch.
Caution:
In the process of spanning tree root election, of two or more switches with the lowest
Bridge priorities, the one has a smaller MAC address will be elected as the root.
By default, the switch Bridge priority is 32768.

1.2.5 Configure the Max Hops in an MST Region

The scale of MST region is limited by the max hops in an MST region, which is
configured on the region root. As the BPDU traveling from the spanning tree root, each
time when it is forwarded by a switch, the max hops is reduced by 1. The switch
discards the configuration BPDU with 0 hops left. This makes it impossible for the
switch beyond the max hops to take part in the spanning tree calculation, thereby
limiting the scale of the MST region.
Operation
Huawei Technologies Proprietary
1-14
Chapter 1 MSTP Region-configuration
Command
stp [ instance instance-id ] priority
priority
undo stp [ instance instance-id ]
priority priority