R3303-HP HSR6800 Routers Layer 2 - LAN Switching Configuration Guide

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Step Command Remarks
4. Configure the
VLAN-to-instance mapping
table.
instance instance-id vlan vlan-list
Or
vlan-mapping modulo modulo
Optional.
All VLANs in an MST region are
mapped to the CIST (or MSTI 0) by
default.
5. Configure the MSTP revision
level of the MST region.
revision-level level
Optional.
The default setting is 0.
6. Display the MST region
configurations that are not
activated yet.
check region-configuration Optional.
7. Activate MST region
configuration manually.
active region-configuration
N/A
8. Display the activated
configuration information of
the MST region.
display stp region-configuration [ |
{ begin | exclude | include }
regular-expression ]
Optional.
Available in any view.
Configuring the root bridge or a secondary root
bridge
You can have MSTP determine the root bridge of a spanning tree through MSTP calculation, or you can
specify the current device as the root bridge or as a secondary root bridge.
A device has independent roles in different spanning trees. It can act as the root bridge in one spanning
tree and as a secondary root bridge in another. However, one device cannot be the root bridge and a
secondary root bridge in the same spanning tree.
A spanning tree can have one root bridge only. If two or more devices are selected as the root bridge at
the same time, the device with the lowest MAC address is chosen.
When the root bridge of an instance fails or is shut down, the secondary root bridge (if you have
specified one) can take over the role of the primary root bridge. However, if you specify a new primary
root bridge for the instance, the one that you specify, and not the secondary root bridge, will become the
root bridge. If you have specified multiple secondary root bridges for an instance, when the root bridge
fails, the secondary root bridge with the lowest MAC address is selected as the new root bridge.
You can specify one root bridge for each spanning tree, regardless of the device priority settings. Once
you specify a device as the root bridge or a secondary root bridge, you cannot change its priority.
You can 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."
Configuring the current device as the root bridge of a specific
spanning tree
To configure the current device as the root bridge of a specific spanning tree: