• Enable root guard on a port or port-channel interface.INTERFACE mode or INTERFACE PORT-CHANNEL modespanning-tree {0 | mstp | rstp | pvst} rootguard– 0: enables root guard on an STP-enabled port assigned to instance 0.– mstp: enables root guard on an MSTP-enabled port.– rstp: enables root guard on an RSTP-enabled port.– pvst: enables root guard on a PVST-enabled port.To disable STP root guard on a port or port-channel interface, use the no spanning-tree 0rootguard command in an interface configuration mode.To verify the STP root guard configuration on a port or port-channel interface, use the show spanning-tree 0 guard [interface interface] command in a global configuration mode.Enabling SNMP Traps for Root Elections and TopologyChangesTo enable SNMP traps individually or collectively, use the following commands.• Enable SNMP traps for spanning tree state changes.snmp-server enable traps stp• Enable SNMP traps for RSTP, MSTP, and PVST+ collectively.snmp-server enable traps xstpConfiguring Spanning Trees as HitlessYou can configure STP, RSTP, MSTP, and PVST+ to be hitless (configure all or none as hitless). Whenconfigured as hitless, critical protocol state information is synchronized between the RPMs so that RPMfailover is seamless and no topology change is triggered.To be hitless per spanning tree type or for all spanning tree types, use the following commands.• Configure LACP to be hitless.CONFIGURATION moderedundancy protocol lacp• Configure all spanning tree types to be hitless.CONFIGURATION moderedundancy protocol xstpExample of Configuring all Spanning Tree Types to be HitlessDell(conf)#redundancy protocol xstpDell#show running-config redundancy!redundancy protocol xstpDell#Spanning Tree Protocol (STP) 879
