Dell MX9116n EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 538

You can set the priority value to 0 to force a switch to become the root switch. Value 0 is the highest priority. ● Assign a bridge priority number to a specific instance in CONFIGURATION mode, from 0 to 61440 in increments of 4096, default 32768. spanning-tree mst instance-number priority priority Assign root bridge priority OS10(config)# spanning-tree mst 0 priority 32768 Verify root bridge priority OS10# show spanning-tree active Spanning tree enabled protocol msti with force-version mst MSTI 0 VLANs mapped 1,31-4093 Executing IEEE compatible Spanning Tree Protocol Root ID Priority 32768, Address 3417.4455.667f Root Bridge hello time 2, max age 20, forward delay 15, max hops 20 Bridge ID Priority 32768, Address 90b1.1cf4.a523 Configured hello time 2, max age 20, forward delay 15, max hops 20 CIST regional root ID Priority 32768, Address 90b1.1cf4.a523 CIST external path cost 500 Interface Designated Name PortID Prio Cost Sts Cost Bridge ID PortID ethernet1/1/5 128.276 128 500 FWD 0 32768 3417.4455.667f 128.146 ethernet1/1/6 128.280 128 500 BLK 0 32768 3417.4455.667f 128.150 Interface Name Role PortID Prio Cost Sts Cost Link-type Edge ethernet1/1/5 Root 128.276 128 500 FWD 0 AUTO No ethernet1/1/6 Altr 128.280 128 500 BLK 0 AUTO No Non-Dell EMC hardware OS10 supports only one MST region. For a bridge to be in the same MST region as another, the following attributes must match the unique name, revision, and VLAN mapping. The default value for name is system mac. In case of Dell EMC, the user has to manually configure an unique name in all the nodes to be in a single region. If you have non-Dell EMC hardware that participates in MST, ensure these values match on all devices. A region is a combination of three unique attributes: ● Name - A mnemonic string you assign to the region. The default is the system MAC address. ● Revision - A 2-byte number. The default is 0. ● VLAN-to-instance mapping - Placement of a VLAN in an MSTI. Region name or revision You can change the MSTP region name or revision. ● Change the region name in MULTIPLE-SPANNING-TREE mode. A maximum of 32 characters. name name ● Change the region revision number in MULTIPLE-SPANNING-TREE mode, from 0 to 65535, default 0. revision number Configure and verify region name OS10(conf-mstp)# name my-mstp-region OS10(conf-mstp)# do show spanning-tree mst config MST region name: my-mstp-region Revision: 0 MSTI VID 538 Layer 2