Concept Guide

Version : 6(3)
Local System MAC address : 00:01:e8:8a:e9:91
Remote System MAC address : 00:01:e8:8a:e9:76
Remote system version : 6(3)
Delay-Restore timer : 90 seconds
Delay-Restore Abort Threshold : 60 seconds
Peer-Routing : Disabled
Peer-Routing-Timeout timer : 0 seconds
Multicast peer-routing timeout : 150 seconds
Dell#
Dell#FTOS(conf-if-vl-100)#show vlt detail
Local LAG Id Peer LAG Id Local Status Peer Status Active VLANs
------------ ----------- ------------ ------------ -------------
10 10 UP UP 100, 200, 300, 400,
Verify the VLT LAG is up in both VLT peer units
fniom-2#show interfaces port-channel 2 brief
Codes: L - LACP Port-channel
LAG Mode Status Uptime Ports
L 2 L2L3 up 03:43:24 Te 0/40 (Up)
fniom-2#
fniom-4#show interfaces port-channel 2 brief
Codes: L - LACP Port-channel
LAG Mode Status Uptime Ports
L 2 L2L3 up 03:33:31 Te 0/18 (Up)
fniom-4#
PVST+ Conguration
PVST+ is supported in a VLT domain.
Before you congure VLT on peer switches, congure PVST+ in the network. PVST+ is required for initial loop prevention during the VLT
startup phase. You may also use PVST+ for loop prevention in the network outside of the VLT port channel. For information on PVST+,
refer to Per-VLAN Spanning Tree Plus (PVST+).
Run PVST+ on both VLT peer switches. PVST+ instance will be created for every VLAN congured in the system. PVST+ instances running
in the Primary Peer will control the VLT-LAGs on both Primary and Secondary peers. Only the Primary VLT switch determines the PVST+
roles and states on VLT ports and ensures that the VLT interconnect link is never blocked. PVST+ instance in Primary peer will send the
role/state of VLT-LAGs for all VLANs to the Secondary peer. Secondary peer will use this information to program the hardware. PVST+
instance running in Secondary peer will not control the VLT-LAGs.
Dell Networking recommends conguring the primary VLT peer as the primary root device for all the congured PVST+ Instances and
conguring the secondary VLT peer as the secondary root device for all the congured PVST+ Instances.
Sample PVST+ Conguration
The following examples show the PVST+ conguration that you must perform on each peer switch to prevent forwarding loops.
Congure PVST+ on VLT Peers to Prevent Forwarding Loops (VLT Peer 1)
Dell_VLTpeer1(conf)#protocol spanning-tree pvst
Dell_VLTpeer1(conf-pvst)#no disable
Dell_VLTpeer1(conf-pvst)#vlan 1000 bridge-priority 0
Congure PVST+ on VLT Peers to Prevent Forwarding Loops (VLT Peer 2)
Dell_VLTpeer2(conf)#protocol spanning-tree pvst
Dell_VLTpeer2(conf-pvst)#no disable
Dell_VLTpeer2(conf-pvst)#vlan 1000 bridge-priority 4096
Virtual Link Trunking (VLT)
945