3com WX3000 Manuel D’Utilisation
1-22
Configuration example
# Specify the MSTP operation mode as STP-compatible.
<device> system-view
[device] stp mode stp
Configuring the Maximum Hop Count of an MST Region
The maximum hop count configured on the region root is also the maximum hops of the MST region.
The value of the maximum hop count limits the size of the MST region.
The value of the maximum hop count limits the size of the MST region.
A configuration BPDU contains a field that maintains the remaining hops of the configuration BPDU.
And the device discards the configuration BPDUs whose remaining hops are 0. After a configuration
BPDU reaches a root bridge of a spanning tree in an MST region, the value of the remaining hops field
in the configuration BPDU is decreased by 1 every time the configuration BPDU passes one device.
Such a mechanism disables the devices that are beyond the maximum hop count from participating in
spanning tree calculation, and thus limits the size of an MST region.
And the device discards the configuration BPDUs whose remaining hops are 0. After a configuration
BPDU reaches a root bridge of a spanning tree in an MST region, the value of the remaining hops field
in the configuration BPDU is decreased by 1 every time the configuration BPDU passes one device.
Such a mechanism disables the devices that are beyond the maximum hop count from participating in
spanning tree calculation, and thus limits the size of an MST region.
With such a mechanism, the maximum hop count configured on the device operating as the root bridge
of the CIST or an MSTI in an MST region becomes the network diameter of the spanning tree, which
limits the size of the spanning tree in the current MST region. The devices that are not root bridges in the
MST region adopt the maximum hop settings of their root bridges.
of the CIST or an MSTI in an MST region becomes the network diameter of the spanning tree, which
limits the size of the spanning tree in the current MST region. The devices that are not root bridges in the
MST region adopt the maximum hop settings of their root bridges.
Configuration procedure
Follow these steps to configure the maximum hop count for an MST region:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Configure the maximum hop
count of the MST region
count of the MST region
stp max-hops
hops
Required
By default, the maximum hop
count of an MST region is 20.
By default, the maximum hop
count of an MST region is 20.
The bigger the maximum hop count, the larger the MST region is. Note that only the maximum hop
settings on the device operating as a region root can limit the size of the MST region.
settings on the device operating as a region root can limit the size of the MST region.
Configuration example
# Configure the maximum hop count of the MST region to be 30.
<device> system-view
[device] stp max-hops 30
Configuring the Network Diameter of the Switched Network
In a switched network, any two devices can communicate with each other through a specific path made
up of multiple devices. The network diameter of a network is measured by the number of devices; it
equals the number of the devices on the longest path (that is, the path containing the maximum number
of devices).
up of multiple devices. The network diameter of a network is measured by the number of devices; it
equals the number of the devices on the longest path (that is, the path containing the maximum number
of devices).
Configuration procedure
Follow these steps to configure the network diameter of the switched network: