Virtual Link Trunking (VLT)Virtual link trunking (VLT) allows physical links between two chassis to appear as a single virtual link to thenetwork core. VLT eliminates the requirement for Spanning Tree protocols by allowing link aggregation group(LAG) terminations on two separate distribution or core switches, and by supporting a loop-free topology.VLT provides Layer 2 multipathing, creating redundancy through increased bandwidth and enabling multipleparallel paths between nodes and load-balancing traffic where alternative paths exist.NOTE: When you launch the VLT link, the VLT peer-ship is not established if any of the following is TRUE:• The VLT System-MAC configured on both the VLT peers do not match.• The VLT Unit-Id configured on both the VLT peers are identical.• The VLT System-MAC or Unit-Id is configured only on one of the VLT peers.• The VLT domain ID is not the same on both peers.If the VLT peer-ship is already established, changing the System-MAC or Unit-Id does not cause VLTpeer-ship to go down.Also, if the VLT peer-ship is already established and the VLT Unit-Id or System-MAC are configured onboth peers, then changing the CLI configurations on the VLT Unit-Id or System-MAC is rejected.When the VLT peer-ship is already established, you can remove the VLT Unit-Id or System-MACconfiguration from either or both peers. However, removing configuration settings can cause the VLTports to go down.Topics:• back-up destination• clear vlt statistics• delay-restore• lacp ungroup member-independent• multicast peer-routing timeout• peer-link port-channel• peer-routing• peer-routing-timeout• primary-priority• show vlt brief• show vlt backup-link• show vlt counters• show vlt detail• show vlt inconsistency• show vlt mismatch62Virtual Link Trunking (VLT) 2204
