1-17Configuring the Root BridgeConfiguring an MST RegionConfiguration procedureFollow these steps to configure an MST region:To do... Use the command... RemarksEnter system view system-view —Enter MST region view stp region-configuration —Configure the MST regionname region-name nameOptionalThe MST region name is theMAC address by default.instance instance-id vlan vlan-listConfigure theVLAN-to-MSTI mappingtable vlan-mapping modulo moduloOptionalUse either command.All VLANs in an MST regionare mapped to MSTI 0 bydefault.Configure the MSTPrevision level of the MSTregionrevision-level level Optional0 by defaultActivate MST regionconfiguration manually active region-configuration RequiredDisplay all theconfiguration information ofthe MST regioncheck region-configuration OptionalDisplay the currentlyeffective MST regionconfiguration informationdisplay stp region-configuration The display command canbe executed in any view.Two or more MSTP-enabled devices belong to the same MST region only if they are configured to havethe same MST region name, the same VLAN-to-MSTI mapping entries in the MST region and the sameMST region revision level, and they are interconnected via a physical link.The configuration of MST region–related parameters, especially the VLAN-to-MSTI mapping table, willcause MSTP to launch a new spanning tree calculation process, which may result in network topologyinstability. To reduce the possibility of topology instability caused by configuration, MSTP will notimmediately launch a new spanning tree calculation process when processing MST region–relatedconfigurations; instead, such configurations will take effect only after you:z activate the MST region–related parameters using the active region-configuration command, orz enable MSTP using the stp enable command in the case that MSTP is not enabled.
