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Table Of Contents
Chapter 59: Virtual Link Trunking (VLT).................................................................................... 932
Overview...........................................................................................................................................................................932
VLT Terminology....................................................................................................................................................... 934
Layer-2 Traffic in VLT Domains.............................................................................................................................935
Interspersed VLANs..................................................................................................................................................936
VLT on Core Switches............................................................................................................................................. 936
Enhanced VLT............................................................................................................................................................937
Configure Virtual Link Trunking...................................................................................................................................938
Important Points to Remember............................................................................................................................. 938
Configuration Notes................................................................................................................................................. 939
Primary and Secondary VLT Peers....................................................................................................................... 942
RSTP and VLT........................................................................................................................................................... 942
VLT Bandwidth Monitoring.....................................................................................................................................943
VLT and Stacking...................................................................................................................................................... 943
VLT and IGMP Snooping......................................................................................................................................... 943
VLT IPv6......................................................................................................................................................................943
VLT Port Delayed Restoration............................................................................................................................... 944
PIM-Sparse Mode Support on VLT...................................................................................................................... 944
VLT Routing .............................................................................................................................................................. 946
Non-VLT ARP Sync.................................................................................................................................................. 949
RSTP Configuration....................................................................................................................................................... 949
Preventing Forwarding Loops in a VLT Domain................................................................................................ 949
Sample RSTP configuration................................................................................................................................... 950
Configuring VLT........................................................................................................................................................ 950
PVST+ Configuration.....................................................................................................................................................959
Peer Routing Configuration Example.........................................................................................................................960
Dell-1 Switch Configuration.....................................................................................................................................961
Dell-2 Switch Configuration................................................................................................................................... 964
R1 Configuration........................................................................................................................................................ 967
Access Switch A1 Configurations and Verification........................................................................................... 968
eVLT Configuration Example....................................................................................................................................... 969
PIM-Sparse Mode Configuration Example.................................................................................................................971
Verifying a VLT Configuration......................................................................................................................................972
Additional VLT Sample Configurations...................................................................................................................... 975
Troubleshooting VLT......................................................................................................................................................976
Reconfiguring Stacked Switches as VLT.................................................................................................................. 978
Specifying VLT Nodes in a PVLAN............................................................................................................................. 978
Configuring a VLT VLAN or LAG in a PVLAN........................................................................................................... 981
Creating a VLT LAG or a VLT VLAN..................................................................................................................... 981
Associating the VLT LAG or VLT VLAN in a PVLAN........................................................................................982
Proxy ARP Capability on VLT Peer Nodes................................................................................................................983
VLT Nodes as Rendezvous Points for Multicast Resiliency................................................................................. 984
Configuring VLAN-Stack over VLT............................................................................................................................ 984
IPv6 Peer Routing in VLT Domains Overview..........................................................................................................987
Configure BFD in VLT Domain..................................................................................................................................... 992
Sample BFD configuration in VLT domain...........................................................................................................992
VXLAN on VLT................................................................................................................................................................ 995
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