HP 5400ZL - Manual (Page 168)

Multiple Instance Spanning-Tree Operation
Configuring MSTP
7. To review your pending configuration, use the show spanning-tree pending
command (see page 4-61).
8. To exchange the currently active MSTP configuration with the pending
MSTP configuration, use the spanning-tree pending apply command.
MSTP VLAN Configuration Enhancement
Starting in software release 13.x.x, the MSTP VLAN configuration enhance­
ment allows you to preconfigure an MSTP regional topology and ensure that
the same VLAN ID-to-MSTI assignments exist on each MSTP switch in the
region.
C a u t i o n When this software version is installed, the prior VLAN ID-to-MSTI mappings
do not change. However, this enhancement is not backward-compatible. If you
install a software version prior to this version, and you have configured MSTI
entries instances mapped to VLANs, they will be removed from the configu­
ration file when booting to the prior version of software. You must do one of
the following if you want to install or reload a prior version of the software:
1. Remove all MSTP mappings from the config file and then reconfigure the
instance mapping after you are running the desired software version.
2. Save your current configuration file before updating your software to a
new version. If you later reload this older version of the software, you
can used this configuration file when you reload the older version. See
“How to Save Your Current Configuration” on page 4-51.
The default behavior of the spanning-tree instance vlan command changes
so that, before a static VLAN is configured or a dynamic VLAN is learned on
the switch, you can preconfigure its VLAN ID-to-MSTI mapping. Later, when
the VLAN is created, it is automatically assigned to the MSTI to which you had
previously mapped it.
By supporting preconfigured VLAN ID-to-MSTI topologies, the VLAN Config­
uration enhancement provides the following benefits:
■ Scalability: In a network design in which you plan to use a large number
of VLANs, you can preconfigure identical VLAN ID-to-MSTI mappings on
all switches in a single, campus-wide MST region, regardless of the
specific VLANs that you later configure on each switch. After the initial
VLAN ID-to-MSTI mapping, you can decide on the exact VLANs that you
need on each switch.
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