Developers Guide

Table Of Contents
Chapter 59: Virtual Link Trunking (VLT).................................................................................... 936
Overview...........................................................................................................................................................................936
VLT Terminology....................................................................................................................................................... 938
Layer-2 Traffic in VLT Domains.............................................................................................................................939
Interspersed VLANs..................................................................................................................................................940
VLT on Core Switches............................................................................................................................................. 940
Enhanced VLT............................................................................................................................................................ 941
Configure Virtual Link Trunking...................................................................................................................................942
Important Points to Remember............................................................................................................................. 942
Configuration Notes................................................................................................................................................. 943
Primary and Secondary VLT Peers....................................................................................................................... 946
RSTP and VLT........................................................................................................................................................... 946
VLT Bandwidth Monitoring.....................................................................................................................................947
VLT and Stacking...................................................................................................................................................... 947
VLT and IGMP Snooping......................................................................................................................................... 947
VLT IPv6......................................................................................................................................................................947
VLT Port Delayed Restoration............................................................................................................................... 948
PIM-Sparse Mode Support on VLT...................................................................................................................... 948
VLT Routing .............................................................................................................................................................. 950
Non-VLT ARP Sync.................................................................................................................................................. 953
RSTP Configuration....................................................................................................................................................... 953
Preventing Forwarding Loops in a VLT Domain................................................................................................ 953
Sample RSTP configuration....................................................................................................................................954
Configuring VLT........................................................................................................................................................ 954
PVST+ Configuration.....................................................................................................................................................963
Peer Routing Configuration Example......................................................................................................................... 964
Dell-1 Switch Configuration....................................................................................................................................965
Dell-2 Switch Configuration................................................................................................................................... 968
R1 Configuration.........................................................................................................................................................971
Access Switch A1 Configurations and Verification........................................................................................... 972
eVLT Configuration Example........................................................................................................................................973
PIM-Sparse Mode Configuration Example................................................................................................................975
Verifying a VLT Configuration......................................................................................................................................976
Additional VLT Sample Configurations...................................................................................................................... 979
Troubleshooting VLT......................................................................................................................................................980
Reconfiguring Stacked Switches as VLT.................................................................................................................. 982
Specifying VLT Nodes in a PVLAN.............................................................................................................................982
Configuring a VLT VLAN or LAG in a PVLAN.......................................................................................................... 985
Creating a VLT LAG or a VLT VLAN.................................................................................................................... 985
Associating the VLT LAG or VLT VLAN in a PVLAN........................................................................................986
Proxy ARP Capability on VLT Peer Nodes................................................................................................................987
VLT Nodes as Rendezvous Points for Multicast Resiliency................................................................................. 988
Configuring VLAN-Stack over VLT............................................................................................................................ 988
IPv6 Peer Routing in VLT Domains Overview.......................................................................................................... 991
Configure BFD in VLT Domain.....................................................................................................................................996
Sample BFD configuration in VLT domain.......................................................................................................... 996
VXLAN on VLT................................................................................................................................................................ 999
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