Dell OS10 VLT Setup: Step-by-Step Virtual Link Trunking Guide

Dell OS10 does not support physical stacking — instead, two identical PowerSwitch units join into a Virtual Link Trunking (VLT) domain: a single logical extended switch with active-active ports, high availability, and no spanning-tree blocked uplinks for the connected servers or switches. Based on Dell's official KB 000102901, this guide walks through the complete VLT setup: spanning-tree mode, the VLT domain and VLTi interconnect, priority and MAC, backup link, and the VLT port-channel that faces the attached device.

Step 1: Configure Spanning Tree Mode

Spanning tree is enabled by default and recommended to prevent loops in the VLT domain. RPVST+ (default) and RSTP are supported on VLT ports:

OS10# configure terminal
OS10(config)# spanning-tree mode rstp
OS10(config)# spanning-tree mode rapid-pvst

Step 2: Create the VLT Domain and VLTi

The VLT interconnect (VLTi) carries control traffic and data between the peers. Remove switchport mode from the VLTi ports and designate them as discovery interfaces:

OS10# configure terminal
OS10(config)# interface range ethernet 1/1/1-1/1/2
OS10(conf-range-eth1/1/1-1/1/2)# no switchport
OS10(config)# vlt-domain 1
OS10(conf-vlt-1)# discovery-interface ethernet 1/1/1
OS10(conf-vlt-1)# discovery-interface ethernet 1/1/2

Step 3: Priority, VLT MAC and Backup Link

OS10(config)# vlt-domain 1
OS10(conf-vlt-1)# primary-priority 4096   (primary peer)
OS10(conf-vlt-1)# primary-priority 8192   (secondary peer)
OS10(conf-vlt-1)# vlt-mac 00:11:22:33:44:55
OS10(conf-vlt-1)# backup destination 100.1.1.2

The VLT MAC must be unique and identical on both peers; the backup destination is the management/backup link used when the VLTi fails.

Step 4: Configure the VLT Port-Channel

Create the LAG to the end device using the same LAG number on both peers, and mark it as a VLT port-channel:

OS10# configure terminal
OS10(config)# interface port-channel 5
OS10(conf-if-po-5)# vlt-port-channel 5
OS10(config)# interface ethernet 1/1/10
OS10(conf-if-eth1/1/10)# channel-group 5 mode active

VLT port-channels are LACP-negotiated (dynamic) LAGs, so use channel-group <n> mode active on both peers.

Verify the VLT Domain

OS10# show vlt 1
OS10# show vlt 1 vlt-port-detail
OS10# show interface port-channel summary

Confirm both peers show the VLT domain up, the VLTi is operational, and the port-channel status is Active.

Related OS10 Content on This Site

See also OS10 factory reset and default gateway, OS10 management interface configuration and Cisco Nexus vPC failover (the equivalent on Nexus).

原文链接：https://www.dell.com/support/kbdoc/en-us/000102901/dell-emc-networking-os10-how-to-set-up-virtual-link-trunking-vlt