Administrator Guide

Virtual Link Trunking (VLT)

Virtual link trunking (VLT) is a Dell EMC technology that provides two Dell EMC switches the ability to function as a single

switch. VLT allows physical links between two Dell EMC switches to appear as a single virtual link to the network core or other

switches such as Edge, Access, or top-of-rack (ToR). As a result, the two physical switches appear as a single switch to the

connected devices.

Topics:

• Overview

• Configure Virtual Link Trunking

• RSTP Configuration

• PVST+ Configuration

• Peer Routing Configuration Example

• eVLT Configuration Example

• PIM-Sparse Mode Configuration Example

• Verifying a VLT Configuration

• Additional VLT Sample Configurations

• Troubleshooting VLT

• Reconfiguring Stacked Switches as VLT

• Specifying VLT Nodes in a PVLAN

• Configuring a VLT VLAN or LAG in a PVLAN

• Proxy ARP Capability on VLT Peer Nodes

• VLT Nodes as Rendezvous Points for Multicast Resiliency

• Configuring VLAN-Stack over VLT

• IPv6 Peer Routing in VLT Domains Overview

• Configure BFD in VLT Domain

Overview

In a traditional switched topology as shown below, spanning tree protocols (STPs) are used to block one or more links to

prevent loops in the network. Although loops are prevented, bandwidth of all links is not effectively utilized by the connected

devices.

Figure 125. Traditional switched topology

VLT not only overcomes this caveat, but also provides a multipath to the connected devices. In the example shown below, the

two physical VLT peers appear as a single logical device to the connected devices. As the connected devices consider the VLT

Virtual Link Trunking (VLT) 915