Concept Guide

Congure RSTP on VLT peers to prevent forwarding loops—VLT peer 1
(primary)
Dell_VLTpeer1(conf)#protocol spanning-tree rstp
Dell_VLTpeer1(conf-rstp)#no disable
Dell_VLTpeer1(conf-rstp)#bridge-priority 4096
Congure RSTP on VLT peers to prevent forwarding loops—VLT peer 2
(secondary)
Dell_VLTpeer2(conf)#protocol spanning-tree rstp
Dell_VLTpeer2(conf-rstp)#no disable
Dell_VLTpeer2(conf-rstp)#bridge-priority 8192
NOTE: When you remove the VLT conguration, RSTP is recommended as a backup solution to avoid spanning—tree loops. In
this case, you can use the following RSTP default values:
• hello–time: 2 seconds
• forward–delay: 15 seconds
• max–age: 20
There is no additional performance gain on VLT, if you congure the RSTP values other than the default values.
Conguring VLT
To congure VLT, use the following procedure.
Prerequisites:
Before you begin, make sure that both VLT peer switches are running the same Dell EMC Networking OS version and are congured for
RSTP as described in the RSTP Conguration section. For VRRP operation, ensure that you congure VRRP groups and L3 routing on
each VLT peer as described in VLT and VRRP interoperability in the Conguration Notes section. To congure VLT and create a VLT domain
in which two switches are physically connected and treated as a single port channel by access devices, congure the following settings on
each VLT peer device.
1 Congure the VLT interconnect for the VLT domain. The primary and secondary switch roles in the VLT domain are automatically
assigned after you congure both sides of the VLTi.
NOTE
: If you use a third-party ToR unit, to avoid potential problems if you reboot the VLT peers, Dell EMC
recommends using static LAGs on the VLTi between VLT peers.
2 Enable VLT and create a VLT domain ID. VLT automatically selects a system MAC address.
3 Congure a backup link for the VLT domain.
4 (Optional) Manually recongure the default VLT settings, such as the MAC address and VLT primary/ secondary roles.
5 Connect the peer switches in a VLT domain to an attached access device (switch or server).
Conguring a VLT Interconnect
To congure a VLT interconnect, follow these steps.
1 Congure the port channel for the VLT interconnect on a VLT switch and enter interface conguration mode.
Virtual Link Trunking (VLT)
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