Configuring The Maximum Hops Of An Mst Region; Configuring The Network Diameter Of A Switched Network - 3Com 4510G Configuration Manual

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...
Enter system view
Configure the maximum hops
of the MST region

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:
To do...
Enter system view
Configure the network
diameter of the switched
network
Use the command...
system-view
stp max-hops hops
Use the command...
system-view
stp bridge-diameter diameter
4-20
Remarks
—
Required
20 by default
Remarks
—
Required
7 by default