Learning by Doing: CISCO Certified Network ... - SCN Research

An Overview of CISCO Routers and Switches
Objectives:
To become familiar with CISCO networking categories which, in turn, will enable you to
more easily find technical information about networking devices on the CISCO website:
http://www.cisco.com.
Background:
During the course of your studies you may encounter many different models of CISCO
routers and switches. This lab is designed to give you a general overview of how CISCO
routers and switches fit into their “3-layer hierarchical model” which, will allow you to
more easily find technical information about specific models. This lab will also give you
an overview of some of the features of the 2500 and 2600 routers and 1900 and 2900
switches that you may encounter during your CCNA studies.
3-layer Hierarchical model
As you may recall from CISCO textbooks, CISCO strongly suggests using a 3-layer
styled model for designing networks. The “core” of any network design should be
implemented for high-speed switching. This layer just wants to move the information
around as quickly as possible. The distribution layer helps to re-distribute those fast
moving information packets, but may be slowed down by some decision-making from a
router. Finally the access layer is where users connect to the network. This is considered
to be the “slowest” layer because of the extensive decision-making that may be taking
place here.
CORE
DISTRIBUTION
ACCESS
The core layer (high-speed switching) is where you would find the most redundancy
between devices. The distribution layer is where you would find network policy
implementations, some security, and routing between VLAN’s. The access layer is
where you would find your users connected to the network, workgroups, servers, and
some security. As you progress through your studies you will learn more about the
functions of each layer and how they play an important role in network design.
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