Content








Overview











Designing a network can be a challenging
task that involves more than just connecting computers together. A
network requires many features in order to be reliable, manageable, and
scalable. To design reliable, manageable, and scalable networks, a
network designer must realize that each of the major components of a
network has distinct design requirements.
Network design is becoming more
difficult despite improvements in equipment performance and media
capabilities. Using multiple media types and interconnecting LANs with
other external networks makes the networking environment complex. Good
network design will improve performance and also reduce the
difficulties associated with network growth and evolution.
A LAN spans a single
room, a building, or a set of buildings that are close together. A group
of buildings that are on a site and belong to a single organization are
referred to as a campus. The design of larger LANs includes identifying
the following:

An access layer that connects end
users into the LAN
A distribution layer that provides
policy-based connectivity between end-user LANs
A core layer that provides the fastest
connection between the distribution points

Each of these LAN design layers requires
switches that are best suited for specific tasks. The features,
functions, and technical specifications for each switch vary depending
on the LAN design layer for which the switch is intended. Understanding
the role of each layer and then choosing the switches best suited for
that layer ensures the best network performance for LAN users.
Students completing this module should be
able to:

Describe the four major goals of LAN
design
List the key considerations in LAN design
Understand the steps in systematic LAN
design
Understand the design issues
associated with the Layer 1, 2, and 3 LAN structure, or topology
Describe the three-layer design model
Identify the functions of each
layer of the three-layer model
List Cisco access layer switches and
their features
List Cisco distribution layer switches
and their features
List Cisco core layer switches and
their features