To connect our network devices, there are different types of layers and topologies that make up network architectures.

 

 

Most networks use a three tier architecture that divides the network into three layers:

 

 

• Core Layer
• Distribution Layer
• Access. Layer

 

 

 

 

Figure 1: Three-Tier Architecture with Core, Distribution and Access Layers.

 

 

 

The core layer is where Layer 3 routing is done and will have have connections to things like servers and the Internet.

 

 

The distribution layer is used as an aggregation point for the access layer to connect to the core layer.

 

 

The access layer is used to connect end hosts like PC’s and phones.

 

 

Collapsed core is another common network architecture.

 

 

 

 

 

Figure 2: Collapsed Core Architecture

 

 

 

This design simply merges the roles of the core and distribution layers into one. This type of architecture would be for smaller networks that have enough ports to terminate the access layer on the core switches and do not have any distance limitations.