Concept 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.
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 eîectively utilized by the connected devices.
Figure 131. 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 peers as a single switch,
VLT eliminates STP-blocked ports. However, the two VLT devices are independent Layer2/Layer3 (L2/L3) switches for devices in the
upstream network.
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1004 Virtual Link Trunking (VLT)