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The following illustration shows VLT deployed on S5000 switches. The switches appear as a single virtual switch from the point
of view of the switch or server supporting LACP.
Figure 143. Virtual Link Trunking on S5000 Switches
VLT on Core Switches
You can also deploy VLT on core switches.
Uplinks from servers to the access layer and from access layer to the aggregation layer are bundled in LAG groups with
end-to-end Layer 2 multipathing. This set up requires “horizontal” stacking at the access layer and VLT at the aggregation layer
such that all the uplinks from servers to access and access to aggregation are in Active-Active Load Sharing mode. This example
provides the highest form of resiliency, scaling, and load balancing in data center switching networks.
The following illustration shows stacking at the access, VLT in aggregation, and Layer 3 at the core.
The aggregation layer is mostly in the L2/L3 switching/routing layer. For better resiliency in the aggregation, Dell Networking
recommends running the internal gateway protocol (IGP) on the VLTi VLAN to synchronize the L3 routing table across the two
nodes on a VLT system.
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Virtual Link Trunking (VLT)