Dell MX9116n EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 521

spanning-tree vlan vlan-id root primary command ensures that the switch has the lowest bridge priority value by setting the predefined value of 24,576. If an alternate root bridge is required, use the spanning-tree vlan vlan-id root secondary command. The command sets the priority for the switch to the predefined value of 28,672. If the primary root bridge fails, the command ensures that the alternate switch becomes the root bridge. It also assumes that the other switches in the network have a defined default priority value of 32,768. ● Configure the device as the root or secondary root in CONFIGURATION mode. spanning-tree vlan vlan-id root {primary | secondary} ○ vlan-id - Enter the VLAN ID number, from 1 to 4093. ○ primary - Enter the bridge as primary or root bridge. The primary bridge value is 24576. ○ secondary - Enter the bridge as the secondary root bridge. The secondary bridge value is 28672. Configure root bridge as primary OS10(config)# spanning-tree vlan 1 root primary Verify root bridge information OS10# show spanning-tree active Spanning tree enabled protocol rapid-pvst with force-version rstp VLAN 1 Executing IEEE compatible Spanning Tree Protocol Root ID Priority 24577, Address 90b1.1cf4.a523 Root Bridge hello time 2, max age 20, forward delay 15 Bridge ID Priority 24577, Address 90b1.1cf4.a523 We are the root of VLAN 1 Configured hello time 2, max age 20, forward delay 15 Interface Designated Name PortID Prio Cost Sts Cost Bridge ID PortID ethernet1/1/5 128.276 128 500 FWD 0 24577 90b1.1cf4.a523 128.276 ethernet1/1/6 128.280 128 500 LRN 0 24577 90b1.1cf4.a523 128.280 Interface Name Role PortID Prio Cost Sts Cost Link-type Edge ethernet1/1/5 Desg 128.276 128 500 FWD 0 AUTO No ethernet1/1/6 Desg 128.280 128 500 LRN 0 AUTO No Global parameters All non-root bridges accept the timer values on the root bridge. Forward-time Hello-time Max-age Amount of time required for an interface to transition from the Discarding state to the Learning state or from the Learning state to the Forwarding state. Time interval within which the bridge sends BPDUs. Length of time the bridge maintains configuration information before it refreshes information by recomputing the Rapid-PVST topology. ● Modify the forward-time in seconds in CONFIGURATION mode, from 4 to 30, default 15. spanning-tree vlan vlan-id forward-time seconds ● Modify the hello-time in seconds in CONFIGURATION mode, from 1 to 10, default 2. With large configurations involving more numbers of ports, Dell EMC recommends increasing the hello-time. spanning-tree vlan vlan-id hello-time seconds ● Modify the max-age (in seconds) in CONFIGURATION mode, from 6 to 40, default 20. spanning-tree vlan vlan-id max-age seconds Layer 2 521