Administrator Guide

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 example shows stacking at the access, VLT in aggregation, and Layer 3 at the core.
Figure 134. VLT on Core Switches
The aggregation layer is mostly in the L2/L3 switching/routing layer. For better resiliency in the aggregation, Dell EMC
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.
Enhanced VLT
Enhanced VLT (eVLT)) refers to the ability to connect two VLT domains. An eVLT configuration creates a port channel between
two VLT domains by allowing two different VLT domains, using different VLT domain ID numbers, connected by a standard link
aggregation control protocol (LACP) LAG to form a loop-free Layer 2 topology in the aggregation layer.
This configuration supports a maximum of four switches, increasing the number of available ports and allowing for dual
redundancy of the VLT. The following example shows how the core/aggregation port density in the Layer 2 topology is
increased using eVLT. For inter-VLAN routing, you do not need a separate router.
If you enable peer routing in an eVLT topology, a VLT node acts as a proxy gateway for its peer within the VLT domain. You
can also configure the two VLT domains to act as proxy gateways for each other. For more details, see the VLT Proxy Gateway
chapter.
Virtual Link Trunking (VLT)
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