Role : SecondaryRole Priority : 32768ICL Link Status : UpHeartBeat Status : UpVLT Peer Status : UpVersion : 6(3)Local System MAC address : 00:01:e8:8a:e9:91Remote System MAC address : 00:01:e8:8a:e9:76Remote system version : 6(3)Delay-Restore timer : 90 secondsDelay-Restore Abort Threshold : 60 secondsPeer-Routing : DisabledPeer-Routing-Timeout timer : 0 secondsMulticast peer-routing timeout : 150 secondsDell#Verify that the VLT LAG is up in VLT peer unit.Dell-2#show interfaces port-channel 2 briefCodes: L - LACP Port-channelLAG Mode Status Uptime PortsL 2 L2L3 up 03:43:24 Te 1/4 (Up)Dell-4#show interfaces port-channel 2 briefCodes: L - LACP Port-channelLAG Mode Status Uptime PortsL 2 L2L3 up 03:33:31 Te 1/18 (Up)PVST+ ConfigurationPVST+ is supported in a VLT domain.Before you configure VLT on peer switches, configure PVST+ in the network. PVST+ is required for initial loop prevention during the VLTstartup phase. You may also use PVST+ for loop prevention in the network outside of the VLT port channel.Run PVST+ on both VLT peer switches. A PVST+ instance is created for every VLAN configured in the system. PVST+ instances running inthe Primary Peer control the VLT-LAGs on both Primary and Secondary peers. Only the Primary VLT switch determines the PVST+ rolesand states on VLT ports and ensures that the VLT interconnect link is never blocked. The PVST+ instance in Primary peer sends the role/state of VLT-LAGs for all VLANs to the Secondary peer. The Secondary peer uses this information to program the hardware. The PVST+instance running in Secondary peer does not control the VLT-LAGs.Dell Networking recommends configuring the primary VLT peer as the primary root device for all the configured PVST+ Instances andconfiguring the secondary VLT peer as the secondary root device for all the configured PVST+ Instances.Sample PVST+ ConfigurationThe following examples show the PVST+ configuration that you must perform on each peer switch to prevent forwarding loops.Configure PVST+ on VLT Peers to Prevent Forwarding Loops (VLT Peer 1)Dell_VLTpeer1(conf)#protocol spanning-tree pvstDell_VLTpeer1(conf-pvst)#no disableDell_VLTpeer1(conf-pvst)#vlan 1000 bridge-priority 0Configure PVST+ on VLT Peers to Prevent Forwarding Loops (VLT Peer 2)Dell_VLTpeer2(conf)#protocol spanning-tree pvstDell_VLTpeer2(conf-pvst)#no disableDell_VLTpeer2(conf-pvst)#vlan 1000 bridge-priority 40961006 Virtual Link Trunking (VLT)
