Install Guide

Table Of Contents
NOTE: If you use a third-party ToR unit, Dell EMC Networking recommends using static LAGs with VLT peers to avoid
potential problems if you reboot the VLT peers.
Configure the VLT domain with the same ID in VLT peer 1 and VLT peer 2.
Dell-2(conf)#vlt domain 5
Dell-2(conf-vlt-domain)#
Dell-4(conf)#vlt domain 5
Dell-4(conf-vlt-domain)#
Configure the VLTi between VLT peer 1 and VLT peer 2.
1. You can configure the LACP/static LAG between the peer units (not shown).
2. Configure the peer-link port-channel in the VLT domains of each peer unit.
Configure the backup link between the VLT peer units.
1. Configure the peer 2 management ip/ interface ip for which connectivity is present in VLT peer 1.
2. Configure the peer 1 management ip/ interface ip for which connectivity is present in VLT peer 2.
1. Configure the static LAG/LACP between the ports connected from VLT peer 1 and VLT peer 2 to the Top of Rack unit.
2. Configure the VLT peer link port channel id in VLT peer 1 and VLT peer 2.
3. In the Top of Rack unit, configure LACP in the physical ports (shown for VLT peer 1 only. Repeat steps for VLT peer 2. The
bold vlt-peer-lag port-channel 2 indicates that port-channel 2 is the port-channel id configured in VLT peer 2).
In the ToR unit, configure LACP on the physical ports.
Verify VLT is up. Verify that the VLTi (ICL) link, backup link connectivity (heartbeat status), and VLT peer link (peer chassis) are
all up.
DellEMC#show vlt br
VLT Domain Brief
------------------
Domain ID : 1
Role : Secondary
Role Priority : 32768
ICL Link Status : Up
HeartBeat Status : Up
VLT Peer Status : Up
Version : 6(3)
Local System MAC address : 00:01:e8:8a:e9:91
Remote System MAC address : 00:01:e8:8a:e9:76
Remote system version : 6(3)
Delay-Restore timer : 90 seconds
Delay-Restore Abort Threshold : 60 seconds
Peer-Routing : Disabled
Peer-Routing-Timeout timer : 0 seconds
Multicast peer-routing timeout : 150 seconds
DellEMC#
Verify that the VLT LAG is up in VLT peer unit.
PVST+ Configuration
PVST+ is supported in a VLT domain.
Before you configure VLT on peer switches, configure PVST+ in the network. PVST+ is required for initial loop prevention during
the VLT startup phase. You may also use PVST+ for loop prevention in the network outside of the VLT port channel.
Run PVST+ on both VLT peer switches. A PVST+ instance is created for every VLAN configured in the system. PVST+
instances running in the Primary Peer control the VLT-LAGs on both Primary and Secondary peers. Only the Primary VLT switch
determines the PVST+ roles and states on VLT ports and ensures that the VLT interconnect link is never blocked. The PVST+
instance in Primary peer sends the role/state of VLT-LAGs for all VLANs to the Secondary peer. The Secondary peer uses this
information to program the hardware. The PVST+ instance running in Secondary peer does not control the VLT-LAGs.
Dell EMC Networking recommends configuring the primary VLT peer as the primary root device for all the configured PVST+
Instances and configuring the secondary VLT peer as the secondary root device for all the configured PVST+ Instances.
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Virtual Link Trunking (VLT)