Concept Guide

Table Of Contents
65 Virtual Link Trunking (VLT)...................................................................................................................... 906
Overview........................................................................................................................................................................ 906
Multi-domain VLT.....................................................................................................................................................907
VLT Terminology............................................................................................................................................................ 908
Congure Virtual Link Trunking....................................................................................................................................908
Important Points to Remember............................................................................................................................. 908
Conguration Notes................................................................................................................................................909
RSTP and VLT...........................................................................................................................................................912
VLT Bandwidth Monitoring..................................................................................................................................... 912
VLT and IGMP Snooping......................................................................................................................................... 913
VLT Port Delayed Restoration.................................................................................................................................913
PIM-Sparse Mode Support on VLT........................................................................................................................913
VLT Multicast............................................................................................................................................................915
VLT Unicast Routing................................................................................................................................................ 916
Non-VLT ARP Sync.................................................................................................................................................. 917
RSTP Conguration........................................................................................................................................................917
Preventing Forwarding Loops in a VLT Domain.................................................................................................... 917
Sample RSTP Conguration................................................................................................................................... 918
Conguring VLT........................................................................................................................................................918
Conguring a VLT Interconnect..............................................................................................................................918
Conguring a VLT Backup Link...............................................................................................................................919
Conguring a VLT Port Delay Period.....................................................................................................................920
Reconguring the Default VLT Settings (Optional) ........................................................................................... 920
Connecting a VLT Domain to an Attached Access Device (Switch or Server)................................................ 921
Conguring a VLT VLAN Peer-Down (Optional)................................................................................................. 922
Congure Multi-domain VLT (mVLT) (Optional)................................................................................................. 922
Verifying a VLT Conguration.................................................................................................................................924
Connecting a VLT Domain...................................................................................................................................... 927
PVST+ Conguration..................................................................................................................................................... 931
Sample PVST+ Conguration..................................................................................................................................931
mVLT Conguration Example.......................................................................................................................................932
In Domain 1, congure the VLT domain and VLTi on Peer 1Congure mVLT on Peer 1Add links to the
mVLT port-channel on Peer 1Next, congure the VLT domain and VLTi on Peer 2Congure mVLT on
Peer 2Add links to the mVLT port-channel on Peer 2In Domain 2, congure the VLT domain and VLTi
on Peer 3Congure mVLT on Peer 3Add links to the mVLT port-channel on Peer 3Congure the VLT
domain and VLTi on Peer 4Congure mVLT on Peer 4Add links to the mVLT port-channel on Peer 4....... 933
PIM-Sparse Mode Conguration Example.................................................................................................................935
Additional VLT Sample Congurations........................................................................................................................ 936
Conguring Virtual Link Trunking (VLT Peer 1)Conguring Virtual Link Trunking (VLT Peer 2)Verifying a
Port-Channel Connection to a VLT Domain (From an Attached Access Switch)........................................... 936
Troubleshooting VLT......................................................................................................................................................938
Specifying VLT Nodes in a PVLAN..............................................................................................................................939
Association of VLTi as a Member of a PVLAN.....................................................................................................940
MAC Synchronization for VLT Nodes in a PVLAN.............................................................................................. 940
PVLAN Operations When One VLT Peer is Down............................................................................................... 941
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