Users Guide

Figure 4. Distributed Core Architecture: Two-Tier

NOTE: There are no uplinks on the spines. All the leaves have downlinks. Configure the uplink in the

first two leaves.

Key Advantages

The key advantages of a distributed core architecture are:

• Simplified fabric

• Higher bandwidth

• Highly resilient

• Higher availability

• Low power consumption

• Less cooling

• Lower latency

• Lower cost

• Less rack space

• Easier to scale

Distributed Core Terminology

The following terms are unique to the design and deployment of a Layer 3 distributed core fabric.

• Leaf — A switch that connects switches, servers, storage devices, or top-of-rack (TOR) elements. The

role of the leaf switches 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 the leaves switches. The role of the spine is to provide an

interconnect to all the leaves switches. All the ports on the spine switches are used to connect the

leaves, various racks together. The spines provide load balancing and redundancy in the distributed

core. There are no uplinks on the spines.

• Edge ports — The uplinks and downlinks on the leaves.

• Uplinks — An edge port link on the first two leaves in the distributed core fabric that connects to the

edge WAN, which typically connects to an internet server provider (ISP). The uplink can also connect

to a router gateway or an external switch.

• Downlinks — An edge port link that connects the leaves to the data access layer; for example, servers

or ToR elements.

Supported Fabric Types