Configuring The Maximum Hops Of An Mst Region - H3C S9500 Series Operation Manual

Operation Manual – MSTP
H3C S9500 Series Routing Switches
Enter system view
Configure the priority of
the current device
Caution:
Upon specifying the current device as the root bridge or a secondary root bridge,
you cannot configure the priority of the device.
During root bridge selection, if all devices in a spanning tree have the same priority,
the one with the lowest MAC address will be selected as the root bridge of the
spanning tree.
II. Configuration example
# Set the device priority in MSTI 1 to 4096.
<Sysname> system-view
[Sysname] stp instance 1 priority 4096

1.3.5 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 setting configured on the regional root bridge will be used as the
maximum number of hops of the MST region.
The regional root bridge always sends a configuration BPDU with a hop count set to the
maximum value. When a switch receives this configuration BPDU, it decrements the
hop count by 1 and uses the new hop count as the remaining hop count in the
forwarded BPDU. If the hop count of the BPDU reaches 0 at a device, the receiving
device discards the BPDU. As devices beyond the reach of the maximum hop are
unable to take part in spanning tree calculation, the size of the MST region is confined.
When a device becomes the root bridge of the CIST or MSTI of an MST region, the
maximum hop in the configuration BPDUs generated by this device defines the network
diameter of the spanning tree to define how far the spanning tree can reach in this MST
region. All the devices other than the root bridge in the MST region use the maximum
hop value set for the root bridge.
I. Configuration procedure
Follow these steps to configure the maximum hops of the MST region
To do...
system-view
stp [ instance instance-id ]
priority priority
Use the command...
1-24
Chapter 1 MSTP Configuration
Remarks
—
Optional
32768 by default