Explanation/Reference:
Section: Enterprise Network Design Explanation
Explanation:
Of the available choices, you are least likely to implement redundancy and access layer aggregation in the building access layer of an enterprise campus network design. Redundancy is more likely to be implemented between the core and distribution layers. Access layer aggregation is more likely to be implemented in the distribution layer.
The enterprise campus module consists of the following submodules: building access layer, building distribution layer, campus core layer, edge distribution, and data center. The campus core layer of the enterprise campus module provides fast transport services between buildings and the data center.
Because the campus core layer acts as the network's backbone, it is essential that every building distribution layer device have multiple paths to the campus core layer. Multiple paths between the campus core and building distribution layer devices ensure that network connectivity is maintained if a link or device fails in either layer. Layer 3 switching typically takes place in the campus core layer.
The building distribution layer of the enterprise campus module provides link aggregation between layers.
Because the building distribution layer is the intermediary between the building access layer and the campus core layer, the building distribution layer is the ideal place to enforce security policies, provide load balancing, provide Quality of Service (QoS), and perform tasks that involve packet manipulation, such as routing. Because the building distribution layer connects to both the building access layer and the campus core layer, it often comprises multilayer switches that can perform both Layer 3 routing functions and Layer
2 switching functions.
The access layer, which typically comprises Layer 2 switches, serves as a media termination point for devices, such as servers and workstations. Because building access layer devices provide access to the network, the building access layer is the ideal place to perform user authentication and to institute port security. Because the access layer connects directly to end devices, features such as Spanning Tree Protocol (STP), Power over Ethernet (PoE), and virtual LAN (VLAN) access are most likely to be implemented in this layer. High availability, broadcast suppression, and rate limiting are also characteristics of access layer devices.
Reference:
CCDA 200-310 Official Cert Guide, Chapter 2, Enterprise Campus Module, pp. 50-51Category: Enterprise Network Design