Vlt Fabric Terminology; Vlt Components; Typical Vlt Topology - Dell Active Fabric Manager Deployment Manual

interconnect. VLT ensures that local traffic on a chassis does not traverse the VLTi and takes the shortest path to the
destination via directly attached links.

VLT Fabric Terminology

The following terms are unique to the design and deployment of a Layer 2 VLT fabric.
• Leaf — A switch that connects switch, servers, storage devices, or top-of-rack (TOR) elements. The role of the
leaf switch is to provide access to the fabric. The leaf switch connects to all of spines above it in the fabric.
• Spine — A switch that connects to leaf switches. The role of the spine is to provide an interconnect to all the
leaf switches. All the ports on the spine switches are used to connect the leaves, various racks together. The
spines provides load balancing and redundancy in the distributed core. There are no uplinks on the spines.
• Edge ports — The uplinks on the spines and downlinks on the leaves.
• Uplinks — An edge port link on the first two spines in the VLT fabric that connects to outside the fabric.
• Downlinks — An edge port link that connects the leaves to the data access layer. For example, servers or ToR
elements. Downlinks are always 1 Gb or 10 Gb. You must specify an even number of uplinks. The minimum
number of uplinks is 2. One uplink is for redundancy.
• Fabric Interlinks — Links that connect the spines to the leaves. The fabric interlink bandwidth is fixed: 40 Gb or
10 Gb.

VLT Components

Typical VLT Topology

The VLT domain has VLTi (ICL) links connecting between VLT peers and VLT port-channels connecting to a single
access switch, to a switch stack, a server supporting LACP on its NIC, or to another VLT domain as shown in the
following illustration. The backup-link connected through the out-of-band (OOB) management network. Some hosts can
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