Concept Guide

Enabling Null VLAN as the Default VLAN.................................................................................................................. 959
61 Virtual Link Trunking (VLT).......................................................................................................................960
Overview........................................................................................................................................................................ 960
VLT Terminology...................................................................................................................................................... 963
Layer-2 Trac in VLT Domains...............................................................................................................................964
Interspersed VLANs................................................................................................................................................ 965
VLT on Core Switches............................................................................................................................................ 965
Enhanced VLT..........................................................................................................................................................966
Congure Virtual Link Trunking.................................................................................................................................... 967
Important Points to Remember..............................................................................................................................967
Conguration Notes................................................................................................................................................ 968
Primary and Secondary VLT Peers.........................................................................................................................971
RSTP and VLT.......................................................................................................................................................... 972
VLT Bandwidth Monitoring.....................................................................................................................................972
VLT and Stacking..................................................................................................................................................... 972
VLT and IGMP Snooping.........................................................................................................................................972
VLT IPv6....................................................................................................................................................................973
VLT Port Delayed Restoration................................................................................................................................ 973
PIM-Sparse Mode Support on VLT....................................................................................................................... 973
VLT Routing .............................................................................................................................................................975
Non-VLT ARP Sync..................................................................................................................................................978
RSTP Conguration.......................................................................................................................................................979
Preventing Forwarding Loops in a VLT Domain................................................................................................... 979
Sample RSTP conguration....................................................................................................................................979
Conguring VLT....................................................................................................................................................... 980
PVST+ Conguration.................................................................................................................................................... 990
Sample PVST+ Conguration................................................................................................................................. 991
Peer Routing Conguration Example...........................................................................................................................991
Dell-1 Switch Conguration.....................................................................................................................................992
Dell-2 Switch Conguration....................................................................................................................................996
R1 Conguration...................................................................................................................................................... 999
Access Switch A1 Congurations and Verication.............................................................................................1000
eVLT Conguration Example....................................................................................................................................... 1001
eVLT Conguration Step Examples......................................................................................................................1001
PIM-Sparse Mode Conguration Example............................................................................................................... 1003
Verifying a VLT Conguration.....................................................................................................................................1004
Additional VLT Sample Congurations.......................................................................................................................1007
Troubleshooting VLT.................................................................................................................................................... 1009
Reconguring Stacked Switches as VLT................................................................................................................... 1010
Specifying VLT Nodes in a PVLAN.............................................................................................................................1010
Association of VLTi as a Member of a PVLAN.....................................................................................................1011
MAC Synchronization for VLT Nodes in a PVLAN.............................................................................................. 1011
PVLAN Operations When One VLT Peer is Down..............................................................................................1012
PVLAN Operations When a VLT Peer is Restarted............................................................................................ 1012
Interoperation of VLT Nodes in a PVLAN with ARP Requests......................................................................... 1012
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