Specifications

Distribution Layer April 2014
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Distribution Layer
Design Overview
The primary function of the distribution layer is to aggregate access layer switches in a given building or campus.
The distribution layer provides a boundary between the Layer 2 domain of the access layer and the Layer 3
domain that provides a path to the rest of the network. This boundary provides two key functions for the LAN. On
the Layer 2 side the distribution layer creates a boundary for Spanning Tree Protocol limiting propagation of Layer
2 faults. On the Layer 3 side the distribution layer provides a logical point to summarize IP routing information
before it enters the network and reduce IP route tables for easier troubleshooting and faster recovery from
failures.
The LAN distribution layer uses a simplified distribution layer design that is easier to operate and troubleshoot
than the traditional and routed access designs.
Figure 14 - Distribution layer overview
Core Switches
Client
Access
Switches
Client
Access
Switches
Building 1 Building 2 Building 3 Building 4
Distribution
Switches
2102