Cisco LAN Switching Fundamentals

Layer 3 Designs

Designs that incorporate Layer 3/4 aware hardware rather than Layer 2-only aware hardware have many proven benefits including, first and foremost, a reduced reliance on spanning tree for redundancy, followed by more intelligent routing or treatment of traffic. Cisco's current recommendations for switching designs focus on the three-tiered core/distribution/access model, implementing Layer 3 connections between the core and distribution devices, and Layer 2 connections between the distribution and access layers. As Layer 3 switching capabilities become common even in the least expensive access layer switch platforms, the three-tiered model is likely to adopt a Layer 3 switching approach everywhere, not just in the core and distribution ...