Enable Multiple Spanning Tree GloballyMSTP is not enabled by default. To enable MSTP globally, use the following commands.When you enable MSTP, all physical, VLAN, and port-channel interfaces that are enabled and in Layer 2 mode are automatically partof the MSTI 0.• Within an MSTI, only one path from any bridge to any other bridge is enabled.• Bridges block a redundant path by disabling one of the link ports.1. Enter PROTOCOL MSTP mode.CONFIGURATION modeprotocol spanning-tree mstp2. Enable MSTP.PROTOCOL MSTP modeno disableExample of Verifying MSTP is EnabledTo verify that MSTP is enabled, use the show config command in PROTOCOL MSTP mode.Dell(conf)#protocol spanning-tree mstpDell(config-mstp)#show config!protocol spanning-tree mstpno disableDell#Adding and Removing InterfacesTo add and remove interfaces, use the following commands.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 no spanning-tree 0 command, to enable MSTP, use the followingcommand.• spanning-tree 0To remove an interface from the MSTP topology, use the no spanning-tree 0 command.Creating Multiple Spanning Tree InstancesTo 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 modemstiSpecify the keyword vlan then the VLANs that you want to participate in the MSTI.Examples of Configuring and Viewing MSTIThe following examples shows the msti command.Dell(conf)#protocol spanning-tree mstpDell(conf-mstp)#msti 1 vlan 100454 Multiple Spanning Tree Protocol (MSTP)
