Configuring The Device Priority; Configuring The Maximum Hops Of An Mst Region - HP A5830 Configuration Manual

Configure the current device as the root bridge by setting the device priority to 0. For the device priority
configuration, see

Configuring the device priority

CAUTION:

You cannot change the priority of a device while it is configured as the root bridge or as a secondary root
bridge.

During root bridge selection, if all devices in a spanning tree have the same priority, the one with the lowest
MAC address is selected as the root bridge of the spanning tree.
Device priority is a factor in spanning tree calculation. The priority of a device determines whether the
device can be elected as the root bridge of a spanning tree. A lower numeric value indicates a higher
priority. Set the priority of a device to a low value to specify the device as the root bridge of the
spanning tree. A spanning tree device can have different priorities in different MSTIs.
To configure the priority of a device in a specified MSTI:
Step...
1. Enter system view
2. Configure the priority of the
current device (in STP/RSTP
mode)
3. Configure the priority of the
current device (in PVST mode)
4. Configure the priority of the
current device (in MSTP mode)

Configuring the maximum hops of an MST region

By setting the maximum hops of an MST region, you can restrict the region size. The maximum hops
configured on the regional root bridge is used as the maximum hops of the MST region.
Configuration BPDUs sent by the regional root bridge always have a hop count set to the maximum value.
When a device receives this configuration BPDU, it decrements the hop count by 1, and uses the new hop
count in the BPDUs that it propagates. When the hop count of a BPDU reaches 0, it is discarded by the
device that received it. This prevents devices beyond the reach of the maximum hop from participate in
spanning tree calculation, so the size of the MST region is limited.
Make this configuration on the root bridge only. All other devices in the MST region use the maximum
hop value set for the root bridge.
To configure the maximum number of hops of an MST region:
Step...
1. Enter system view
2. Configure the maximum hops
of the MST region
―Configuring the device
Command...
system-view
stp priority priority
stp vlan vlan-list priority priority
stp [ instance instance-id ] priority
priority
Command...
system-view
stp max-hops hops
priority.‖
66
Remarks
—
Required
Use any command
32,768 by default
Remarks
—
Required
20 by default