Setup Guide
Enabling Null VLAN as the Default VLAN.................................................................................................................. 965
58 Virtual Link Trunking (VLT)...................................................................................................................... 966
Overview........................................................................................................................................................................ 966
VLT Terminology...................................................................................................................................................... 969
Layer-2 Trac in VLT Domains...............................................................................................................................970
Interspersed VLANs................................................................................................................................................. 971
VLT on Core Switches..............................................................................................................................................971
Enhanced VLT.......................................................................................................................................................... 972
Congure Virtual Link Trunking.................................................................................................................................... 973
Important Points to Remember..............................................................................................................................973
Conguration Notes.................................................................................................................................................974
Primary and Secondary VLT Peers........................................................................................................................ 977
RSTP and VLT.......................................................................................................................................................... 978
VLT Bandwidth Monitoring.....................................................................................................................................978
VLT and Stacking..................................................................................................................................................... 978
VLT and IGMP Snooping.........................................................................................................................................978
VLT IPv6....................................................................................................................................................................979
VLT Port Delayed Restoration................................................................................................................................ 979
PIM-Sparse Mode Support on VLT....................................................................................................................... 979
VLT Routing ..............................................................................................................................................................981
Non-VLT ARP Sync................................................................................................................................................. 984
RSTP Conguration...................................................................................................................................................... 985
Preventing Forwarding Loops in a VLT Domain................................................................................................... 985
Sample RSTP conguration................................................................................................................................... 985
Conguring VLT....................................................................................................................................................... 986
PVST+ Conguration.................................................................................................................................................... 996
Sample PVST+ Conguration.................................................................................................................................997
Peer Routing Conguration Example.......................................................................................................................... 997
Dell-1 Switch Conguration.................................................................................................................................... 998
Dell-2 Switch Conguration.................................................................................................................................. 1002
R1 Conguration.....................................................................................................................................................1005
Access Switch A1 Congurations and Verication.............................................................................................1006
eVLT Conguration Example.......................................................................................................................................1007
eVLT Conguration Step Examples......................................................................................................................1007
PIM-Sparse Mode Conguration Example............................................................................................................... 1009
Verifying a VLT Conguration......................................................................................................................................1010
Additional VLT Sample Congurations....................................................................................................................... 1013
Troubleshooting VLT.....................................................................................................................................................1015
Reconguring Stacked Switches as VLT................................................................................................................... 1016
Specifying VLT Nodes in a PVLAN.............................................................................................................................1016
Association of VLTi as a Member of a PVLAN.................................................................................................... 1017
MAC Synchronization for VLT Nodes in a PVLAN..............................................................................................1017
PVLAN Operations When One VLT Peer is Down..............................................................................................1018
PVLAN Operations When a VLT Peer is Restarted............................................................................................1018
Interoperation of VLT Nodes in a PVLAN with ARP Requests......................................................................... 1018
30
Contents