Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 1085

Te 0/6 128.263 128 20000 FWD 20000 32768 0001.e805.fb07 128.653 Te 0/7 128.264 128 20000 EDS 20000 32768 0001.e85d.0e90 128.264 Interface Name Role PortID Prio Cost Sts Cost Link-type Edge Te 0/6 Root 128.263 128 20000 FWD 20000 P2P No Te 0/7 ErrDis 128.264 128 20000 EDS 20000 P2P No Dell(conf-if-te-0/7)#do show ip int br te 0/7 Interface IP-Address OK Method Status Protocol TenGigabitEthernet 0/7 unassigned YES Manual up up Selecting STP Root The STP determines the root bridge, but you can assign one bridge a lower priority to increase the likelihood that it becomes the root bridge. You can also specify that a bridge is the root or the secondary root. To change the bridge priority or specify that a bridge is the root or secondary root, use the following command. • Assign a number as the bridge priority or designate it as the root or secondary root. PROTOCOL SPANNING TREE mode bridge-priority {priority-value | primary | secondary} • priority-value: the range is from 0 to 65535. The lower the number assigned, the more likely this bridge becomes the root bridge. The primary option specifies a bridge priority of 8192. The secondary option specifies a bridge priority of 16384. The default is 32768. Example of Viewing STP Root Information To view only the root information, use the show spanning-tree root command from EXEC privilege mode. Dell#show spanning-tree 0 root Root ID Priority 32768, Address 0001.e80d.2462 We are the root of the spanning tree Root Bridge hello time 2, max age 20, forward delay 15 Dell# STP Root Guard Use the STP root guard feature in a Layer 2 network to avoid bridging loops. In STP, the switch in the network with the lowest priority (as determined by STP or set with the bridgepriority command) is selected as the root bridge. If two switches have the same priority, the switch with the lower MAC address is selected as the root. All other switches in the network use the root bridge as the reference used to calculate the shortest forwarding path. Spanning Tree Protocol (STP) 1085