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Multiple Instance Spanning-Tree Operation
Configuring MSTP
To Create a Pending MSTP Configuration.  This procedure creates a 
pending MSTP configuration and exchanges it with the active MSTP configu-
ration:
1. Configure the VLANs you want included in any instances in the new 
region. When you execute the pending command, all VLANs configured on 
the switch will be assigned to a single pending IST instance unless 
assigned to other, pending MST instances.(The pending command creates 
the region’s IST instance automatically.)
2. Configure MSTP as the spanning-tree protocol, then execute write mem 
and reboot. (The pending option is available only with MSTP enabled.)
3. Configure the pending region config-name to assign to the switch.
4. Configure the pending config-revision number for the region name. 
5. If you want an MST instance other than the IST instance, configure the 
instance number and assign the appropriate VLANs (VIDs) using the 
pending instance < 1..16  > vlan  < vid  | vid-range > command.
6. Repeat step 5 for each additional MST instance you want to configure.
Syntax: [no] spanning-tree pending < apply | config-name | config-revision | 
instance | reset >
This command exchanges the currently active MSTP 
configuration with the current pending MSTP configuration. 
Options are as follows:
apply: Exchanges the currently active MSTP configuration 
with the pending MSTP configuration. 
config-name: Specifies the pending MST region name. Must be 
the same for all MSTP switches in the region. 
(Default: The switch’s MAC address.)
config-revision: Specifies the pending MST region 
configuration revision number. Must be the same for all MSTP 
switches in the region. 
(Default: 0).
instance < 1..16  > vlan  < vid  | vid-range >: Creates the pending 
instance and assigns one or more VLANs to the instance.
reset: Copies the switch’s currently active MSTP configuration 
to the pending configuration. This is useful when you want to 
experiment with the current MSTP configuration while 
maintaining an unchanged version.