Creating Multiple Spanning Tree Instances; Influencing Mstp Root Selection - Dell S6100 Configuration Manual

• spanning-tree 0
To remove an interface from the MSTP topology, use the no spanning-tree 0 command.

Creating Multiple Spanning Tree Instances

To create multiple spanning tree instances, use the following command.
A single MSTI provides no more benefit than RSTP. To take full advantage of MSTP, create multiple MSTIs and map VLANs to them.
• Create an MSTI.
PROTOCOL MSTP mode
msti
Specify the keyword vlan then the VLANs that you want to participate in the MSTI.
Examples of Configuring and Viewing MSTI
The following examples shows the msti command.
Dell(conf)#protocol spanning-tree mstp
Dell(conf-mstp)#msti 1 vlan 100
Dell(conf-mstp)#msti 2 vlan 200-300
Dell(conf-mstp)#show config
!
protocol spanning-tree mstp
no disable
MSTI 1 VLAN 100
MSTI 2 VLAN 200-300
All bridges in the MSTP region must have the same VLAN-to-instance mapping.
To view which instance a VLAN is mapped to, use the show spanning-tree mst vlan command from EXEC Privilege mode.
Dell(conf-mstp)#name my-mstp-region
Dell(conf-mstp)#exit
Dell(conf)#do show spanning-tree mst config
MST region name: my-mstp-region
Revision: 0
MSTI VID
1 100
2 200-300
To view the forwarding/discarding state of the ports participating in an MSTI, use the show spanning-tree msti command from
EXEC Privilege mode.

Influencing MSTP Root Selection

MSTP determines the root bridge, but you can assign one bridge a lower priority to increase the probability that it becomes the root bridge.
To change the bridge priority, use the following command.
• Assign a number as the bridge priority.
PROTOCOL MSTP mode
msti instance bridge-priority priority
A lower number increases the probability that the bridge becomes the root bridge.
The range is from 0 to 61440, in increments of 4096.
The default is 32768.
560 Multiple Spanning Tree Protocol (MSTP)