Information Technology Reference
In-Depth Information
applications, Dynamic Host Configuration Protocol (DHCP), Domain Name System
(DNS), intranet, and other services.
Enterprise Campus LANs
A campus LAN connects two or more buildings within a local geographic area using a
high-bandwidth LAN media backbone. Usually the enterprise owns the medium (copper
or fiber). High-speed switching devices minimize latency. In today's networks, Gigabit
Ethernet campus backbones are the standard for new installations. In Figure 3-11, Layer 3
switches with Gigabit Ethernet media connect campus buildings.
Building A
Building B
Building C
Si
Si
Si
Si
Si
Si
Si
Si
Si
Campus Backbone
GE or 10GE Links
Si
Si
Si
Si
Si
Si
Si
Si
Si
Building D
Building E
Building F
Figure 3-11
Campus LAN
Ensure that you implement a hierarchical composite design on the campus LAN and that
you assign network layer addressing to control broadcasts on the networks. Each building
should have addressing assigned in such a way as to maximize address summarization. Ap-
ply contiguous subnets to buildings at the bit boundary to apply summarization and ease
the design. Campus networks can support high-bandwidth applications such as video con-
ferenc ing. Remember to u s e L ayer 3 s w itche s w ith high-s w itching c apabilit ie s in the c am -
pus-backbone design. In smaller installations, it might be desirable to collapse the
building-distribution component into the campus backbone. An increasingly viable alter-
native is to provide building access and distribution on a single device selected from
among the smaller Layer 3 switches now available.
