Switching Architectures Hierarchical Model – Core Layer

Hierarchical Model – Core Layer

The core layer is responsible for connecting all distribution layer switches.

The core is often referred to as the network backbone, as it forwards traffic
from to every end of the network.

Switches at the core layer typically have the following characteristics:
• High-throughput Layer-3 or multilayer forwarding
• Absence of traffic filtering, to limit latency
• Scalable, redundant links to the distribution layer and other core
switches
• Advanced QoS functions

Proper core layer design is focused on speed and efficiency. In a 20/80
design, most traffic will traverse the core layer. Thus, core switches are often
the highest-capacity switches in the campus environment.

Smaller campus environments may not require a clearly defined core layer
separated from the distribution layer. Often, the functions of the core and
distribution layers are combined into a single layer. This is referred to as a
collapsed core design.

(Reference: CCNP Switch 642-813 Official Certification Guide by David Hucaby. Cisco Press)