Configuring The Root Bridge Or A Secondary Root Bridge - HP 6125XLG Configuration Manual

MST region revision level.
•
• VLAN-to-instance mapping entries in the MST region.
The configuration of MST region-related parameters (especially the VLAN-to-instance mapping table)
might cause MSTP to begin a new spanning tree calculation. To reduce the possibility of topology
instability, the MST region configuration takes effect only after you activate it by doing one of the
following:
• Use the active region-configuration command.
Enable a spanning tree protocol by using the stp global enable command if the spanning tree
•
protocol is disabled.
In STP, RSTP, or PVST mode, MST region configurations do not take effect.
To configure an MST region:
Step
1. Enter system view.
2. Enter MST region view.
3. Configure the MST region
name.
4. Configure the
VLAN-to-instance mapping
table.
5. Configure the MSTP revision
level of the MST region.
6. (Optional.) Display the MST
region configurations that are
not activated yet.
7. Manually activate MST region
configuration.
Configuring the root bridge or a secondary root
bridge
You can have the spanning tree protocol determine the root bridge of a spanning tree through
calculation. You can also specify a 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 only one root bridge. If multiple devices can be selected as the root bridge in
a spanning tree, the device with the lowest MAC address is selected.
When the root bridge of an instance fails or is shut down and no new root bridge is specified:
• If you specify only one secondary root bridge, it becomes the root bridge.
Command
system-view
stp region-configuration
region-name name
•
instance instance-id vlan
vlan-id-list
•
vlan-mapping modulo modulo
revision-level level
check region-configuration
active region-configuration
93
Remarks
N/A
N/A
The default setting is the MAC
address.
Use one of the commands.
By default, all VLANs in an MST
region are mapped to the CIST (or
MSTI 0).
The default setting is 0.
N/A
N/A