Configuring The Root Bridge Or A Secondary Root Bridge - HP 5820X series Configuration Manual

To configure an MST region:
To do...
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. Display the MST region
configurations that are not
activated yet
7. Activate MST region
configuration manually
8. Display the activated
configuration information of
the MST region
Two or more MSTP-enabled devices belong to the same MST region only if they are configured to have
the same format selector (0 by default, not configurable), MST region name, the same VLAN-to-instance
mapping entries in the MST region and the same MST region revision level, and they are interconnected
via a physical link.
The configuration of MST region–related parameters, especially the VLAN-to-instance mapping table, will
cause MSTP to launch a new spanning tree calculation process, which may result in network topology
instability. To reduce the possibility of topology instability caused by configuration, MSTP does not
immediately launch a new spanning tree calculation process when processing MST region–related
configurations; instead, such configurations takes effect only after you activate the MST region–related
parameters by using the active region-configuration command, or enable MSTP by using the stp enable
command in the case that MSTP is disabled.

Configuring the root bridge or a secondary root bridge

MSTP can determine the root bridge of a spanning tree through MSTP calculation. Also, you have the
option of specifying the current device as the root bridge or a secondary root bridge using the commands
provided by the system.
Note the following rules:
A device has independent roles in different MSTIs. It can act as the root bridge or a secondary root
•
bridge of one MSTI and being the root bridge or a secondary root bridge of another MSTI. However,
the same device cannot be the root bridge and a secondary root bridge in the same MSTI at the
same time.
Use the command...
system-view
stp region-configuration
region-name name
instance instance-id vlan vlan-list
vlan-mapping modulo modulo
revision-level level
check region-configuration
active region-configuration
display stp region-configuration
[ | { begin | exclude | include }
regular-expression ]
72
Remarks
—
—
Optional.
The MST region name is the MAC
address by default.
Optional.
Use either command.
All VLANs in an MST region are
mapped to the CIST (or MSTI 0)
by default.
Optional.
0 by default.
Optional.
Required.
Optional.
Available in any view.