Information Technology Reference
In-Depth Information
Large-Building LANs
Large-building LANs are segmented by floors or departments. The building-access com-
ponent serves one or more departments or floors. The building-distribution component
serves one or more building-access components. Campus and building backbone devices
connect the data center, building-distribution components, and the enterprise edge-distri-
bution component. The access layer typically uses Layer 2 switches to contain costs, with
more expensive Layer 3 switches in the distribution layer to provide policy enforcement.
Current best practice is to also deploy multilayer switches in the campus and building
backbone. Figure 3-10 shows a typical large-building design.
Floor
Access
Switches
Building
Distribution
Figure 3-10
Large-Building LAN Design
Each floor can have more than 200 users. Following a hierarchical model of building ac-
cess, building distribution, and core, Fast Ethernet nodes can connect to the Layer 2
switches in the communications closet. Fast Ethernet or Gigabit Ethernet uplink ports
