H3C Technologies H3C S7500E Series Switches - Manual (Page 174)

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To do... Use the command... Remarks
Configure the priority of the current
device in a specified MSTI
stp [ instance instance-id ]
priority priority
Required
32768 by default
After configuring a device as the root bridge or a secondary root bridge, you cannot change 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.
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 will be used as the maximum 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 in the BPDUs it propagates. When the hop count of a BPDU reaches 0, it is discarded
by the device that received it. Thus, devices beyond the reach of the maximum hop can no longer take
part in spanning tree calculation, and thereby the size of the MST region is confined.
Make this configuration on the root bridge only. All the devices other than the root bridge in the MST
region use the maximum hop value set for the root bridge.
Follow these steps to configure the maximum number of hops of an MST region:
To do... Use the command... Remarks
Enter system view system-view —
Configure the maximum hops of
the MST region
stp max-hops hops
Required
20 by default
Configuring the Network Diameter of a Switched Network
Any two terminal devices in a switched network are interconnected through a specific path composed
of a series of devices. The network diameter is the number of devices on the path composed of the
most devices. The network diameter is a parameter that indicates the network size. A bigger network
diameter indicates a larger network size.
Make this configuration on the root bridge only.
Follow these steps to configure the network diameter of a switched network: