Concept Guide

Enabling Null VLAN as the Default VLAN.................................................................................................................. 990
58 Virtual Link Trunking (VLT).......................................................................................................................991
Overview......................................................................................................................................................................... 991
VLT Terminology...................................................................................................................................................... 994
Layer-2 Trac in VLT Domains.............................................................................................................................. 995
Interspersed VLANs................................................................................................................................................ 996
VLT on Core Switches............................................................................................................................................ 996
Enhanced VLT.......................................................................................................................................................... 997
Congure Virtual Link Trunking.................................................................................................................................... 998
Important Points to Remember............................................................................................................................. 998
Conguration Notes................................................................................................................................................ 999
Primary and Secondary VLT Peers...................................................................................................................... 1002
RSTP and VLT........................................................................................................................................................ 1003
VLT Bandwidth Monitoring................................................................................................................................... 1003
VLT and Stacking................................................................................................................................................... 1003
VLT and IGMP Snooping.......................................................................................................................................1003
VLT IPv6..................................................................................................................................................................1004
VLT Port Delayed Restoration.............................................................................................................................. 1004
PIM-Sparse Mode Support on VLT..................................................................................................................... 1004
VLT Routing ........................................................................................................................................................... 1006
Non-VLT ARP Sync................................................................................................................................................1009
RSTP Conguration......................................................................................................................................................1010
Preventing Forwarding Loops in a VLT Domain.................................................................................................. 1010
Sample RSTP conguration...................................................................................................................................1010
Conguring VLT....................................................................................................................................................... 1011
PVST+ Conguration....................................................................................................................................................1021
Sample PVST+ Conguration............................................................................................................................... 1022
Peer Routing Conguration Example.........................................................................................................................1022
Dell-1 Switch Conguration................................................................................................................................... 1023
Dell-2 Switch Conguration.................................................................................................................................. 1027
R1 Conguration.....................................................................................................................................................1030
Access Switch A1 Congurations and Verication..............................................................................................1031
eVLT Conguration Example.......................................................................................................................................1032
eVLT Conguration Step Examples......................................................................................................................1032
PIM-Sparse Mode Conguration Example................................................................................................................1034
Verifying a VLT Conguration.....................................................................................................................................1035
Additional VLT Sample Congurations.......................................................................................................................1038
Troubleshooting VLT.................................................................................................................................................... 1040
Reconguring Stacked Switches as VLT................................................................................................................... 1041
Specifying VLT Nodes in a PVLAN.............................................................................................................................1041
Association of VLTi as a Member of a PVLAN................................................................................................... 1042
MAC Synchronization for VLT Nodes in a PVLAN.............................................................................................1042
PVLAN Operations When One VLT Peer is Down............................................................................................. 1043
PVLAN Operations When a VLT Peer is Restarted........................................................................................... 1043
Interoperation of VLT Nodes in a PVLAN with ARP Requests.........................................................................1043
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