Reference Guide

Figure 139. 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.
Virtual Link Trunking (VLT)
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