A network administrator is planning the upgrade of an enterprise LAN to feature Layer 3 support for the application of data security policies, aggregated links, and redundant devices and links. Which switches in the hierarchical three-layer design model support these network requirements?
- core switches
- access switches
- backbone switches
- distribution switches
Explanation: 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 of the core. This boundary provides two key functions for the LAN. On the Layer 2 side, the distribution layer creates a boundary for Spanning Tree Protocol (STP), limiting propagation of Layer 2 faults. On the Layer 3 side, the distribution layer provides a logical point to summarize IP routing information when it enters the core layer. The distribution switches need to be deployed in pairs for redundancy.