Administrator Guide

Table Of Contents
59 Virtual Link Trunking (VLT)......................................................................................................891
Overview.............................................................................................................................................................................891
VLT Terminology......................................................................................................................................................... 893
Layer-2 Traffic in VLT Domains.................................................................................................................................893
Interspersed VLANs.................................................................................................................................................... 894
VLT on Core Switches................................................................................................................................................895
Enhanced VLT............................................................................................................................................................. 895
Configure Virtual Link Trunking.......................................................................................................................................896
Important Points to Remember.................................................................................................................................896
Configuration Notes....................................................................................................................................................897
Primary and Secondary VLT Peers...........................................................................................................................900
RSTP and VLT.............................................................................................................................................................900
VLT Bandwidth Monitoring.........................................................................................................................................901
VLT and Stacking.........................................................................................................................................................901
VLT and IGMP Snooping.............................................................................................................................................901
VLT IPv6........................................................................................................................................................................901
VLT Port Delayed Restoration....................................................................................................................................901
PIM-Sparse Mode Support on VLT.......................................................................................................................... 902
VLT Routing ................................................................................................................................................................903
Non-VLT ARP Sync.................................................................................................................................................... 906
RSTP Configuration..........................................................................................................................................................906
Preventing Forwarding Loops in a VLT Domain......................................................................................................906
Sample RSTP configuration....................................................................................................................................... 907
Configuring VLT...........................................................................................................................................................907
PVST+ Configuration........................................................................................................................................................ 915
Peer Routing Configuration Example.............................................................................................................................. 916
Dell-1 Switch Configuration.........................................................................................................................................917
Dell-2 Switch Configuration........................................................................................................................................921
R1 Configuration.......................................................................................................................................................... 924
Access Switch A1 Configurations and Verification................................................................................................. 925
eVLT Configuration Example...........................................................................................................................................925
PIM-Sparse Mode Configuration Example.................................................................................................................... 928
Verifying a VLT Configuration......................................................................................................................................... 928
Additional VLT Sample Configurations............................................................................................................................931
Troubleshooting VLT........................................................................................................................................................ 933
Reconfiguring Stacked Switches as VLT.......................................................................................................................934
Specifying VLT Nodes in a PVLAN................................................................................................................................. 934
Configuring a VLT VLAN or LAG in a PVLAN................................................................................................................937
Creating a VLT LAG or a VLT VLAN.........................................................................................................................937
Associating the VLT LAG or VLT VLAN in a PVLAN..............................................................................................938
Proxy ARP Capability on VLT Peer Nodes.....................................................................................................................939
VLT Nodes as Rendezvous Points for Multicast Resiliency........................................................................................ 940
Configuring VLAN-Stack over VLT................................................................................................................................ 940
IPv6 Peer Routing in VLT Domains Overview...............................................................................................................943
Configure BFD in VLT Domain.........................................................................................................................................947
Sample BFD configuration in VLT domain................................................................................................................947
VXLAN on VLT...................................................................................................................................................................951
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