Reference Guide

610 | Multiple Spanning Tree Protocol (MSTP)
www.dell.com | support.dell.com
Adding and Removing Interfaces
• To add an interface to the MSTP topology, configure it for Layer 2 and add it to a VLAN. If you
previously disabled MSTP on the interface using the command
no spanning-tree 0, re-enable it using the
command
spanning-tree 0.
• Remove an interface from the MSTP topology using the command
no spanning-tree 0 command. See
also Removing an Interface from the Spanning Tree Group on page 895 for BPDU Filtering behavior.
Creating Multiple Spanning Tree Instances
A single MSTI provides no more benefit than RSTP. To take full advantage of MSTP you must create
multiple MSTIs and map VLANs to them.
Create an MSTI using the command
msti from PROTOCOL MSTP mode. Specify the keyword vlan
followed by the VLANs that you want to participate in the MSTI, as shown in Figure 32-3.
Figure 32-3. Mapping VLANs to MSTI Instances
All bridges in the MSTP region must have the same VLAN-to-instance mapping. View to which instance a
VLAN is mapped using the command
show spanning-tree mst vlan from EXEC Privilege mode, as shown in
Figure 32-6.
View the forwarding/discarding state of the ports participating in an MSTI using the command
show
spanning-tree msti
from EXEC Privilege mode, as shown in Figure 32-4.
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