1. Cisco Catalyst Switch Family Album
The Cisco Catalyst switch family represents one of the most popular LAN
switches on the market today. The Catalyst range is designed to meet the
needs of a wide range of customers—from small to medium businesses, right
up to large enterprise networks and service providers. Cisco Catalyst
switchesprovide high performance, scalability, manageability, and many other
intelligent features that ensure their success to date.
We can find that Cisco Catalyst switches present one of more difficult product
sets to work with, simply because of the large range of switch families available,
the vast differences in features between low-end and high-end platforms, and
the different operating systems used. When you select a switch platform and
model to use to build a LAN network, you must bear in mind that these
differences exist; otherwise, you might purchase one or more switches that
don't quite do the job you expected.
Cisco Catalyst switches can physically described by one of two device types:
Fixed-configuration switch
Chassis-based switch
The fixed-configuration switch consists of a fixed number or ports
contained within a fixed chassis that includes an internal switch processor.
Some of these devices provide a limited degree of modularity in that they
include modular slots that can be populated by variety of different modules.
The major advantages of fixed-configuration switches are low cost and ease of
deployment. The major disadvantages of a fixed-configuration switch are a lack
of flexibility and the introduction of a multiple management points in the
network when installing more than one switch. Scaling the network by
introducing multiple fixed-configuration switches can also introduce bottlenecks
between each switch.
NOTE
Some Catalyst switches support stacking¸ where a group of Catalyst switches
can be managed as a single entity. Traditionally, the Catalyst 2960 and Cisco
3560 switches have supported stacking; however, inter-switch performance is
limited for larger stacks and the ability to manage the stack as a single entity
has had some restrictions. The recent Catalyst 3750 series of switches now
include stacking technology that includes a high-speed 32 Gbps backplane and
also allows the stack to be completely managed as a single switch.
The chassis-based switch provides a chassis as a starting point, after which
you can add the various components of the switch as you require. You can
determine a particular type of switch processor and switching module, and then

2. install these options. Chassis-based switches provide slots, which support
various types of modules. The major advantages of chassis-based switches
include high performance, flexibility, simplified management, and extended
product lifetime. Chassis-based switches also commonly offer redundancy
features to ensure the failure of a module, power supply, or other component
does not cause a network outage. The major disadvantage of chassis-based
switches is the high cost involved.
Indicates the various models that comprise the Cisco Catalyst switch
family---Table 1-1
Model Format Status
End of Sale
Catalyst Fixed Configuration Recommended
1900/2800 10BASE-T + 100BASE-T Uplinks replacement = Catalyst
2950
End of Sale
Fixed Configuration
Catalyst Recommended
10/100BASE-T + 1000BASE-X
2900XL/3500XL replacement = Catalyst
Uplinks
2950/3550
Legacy
Fixed Configuration
Recommended
Catalyst 2900G 10/100BASE-T + 1000BASE-X
replacement = Catalyst
Uplinks
2950/3550
Fixed Configuration
Catalyst 2950 10/100BASE-T + 1000BASE-X Current
Uplinks
Fixed Configuration
Catalyst 3550 10/100BASE-T + 1000BASE-X Current
Uplinks
Fixed Configuration
Catalyst 3750 10/100/1000BASE-T + Current
1000BASE-X Uplinks
Catalyst
Chassis Current
4000/4500
Legacy
Fixed Configuration Recommended
Catalyst 4900
(n x 1000BASE-X) replacement = Catalyst
3550/3750
Legacy
Catalyst Recommended
Chassis
5000/5500 replacement = Catalyst
6000/6500

3. Model Format Status
Catalyst
Chassis Current
6000/6500
Catalyst
Chassis Current
8000/8500
Each of the Catalyst product families are listed above, with the form factor and
current status of each switch indicated. Each of the product families in bold are
considered current products and are recommended for deployment for new
networks or for network upgrades. All other product families are either end of
sale or considered legacy products that should be purchased only for existing
networks where a common platform needs to be maintained.
Each of the switches in Table 1-1 is targeted at a particular switching
environment, based upon size, network traffic, and features required. One way
of classifying the general role of a switch is to identify the hierarchical layer in
which the switch is operating.
Well-designed LAN networks can be divided into three key layers:
Access— Provides access to the network for end devices, such as user
PCs, servers, and printers.
Distribution— Provides an aggregation point for access-layer devices
and then connects directly to the core. Layer 3 switching can be applied
at this point, which improves convergence and scalability and allows for
the introduction of network policies.
Core— Central portion of the network that interconnects all distribution
layer devices. The core is normally redundant and high-speed. The main
job of the core is to switch traffic as fast as possible, due to the high
volumes of traffic within the core. The core layer can either be a Layer 2
only core or a Layer 3 core that relies on routing for redundancy and
convergence.
For many networks, a network switch can provide the functions of two layers or
even the entire three. Only the very large networks typically have distinct core,
distribution, and access layers; smaller networks typically have a combined
core/distribution layer and an access layer.
Following the core/distribution/access layer design provides a hierarchical
network that can easily scale as the network grows. Figure 1-1 illustrates the
various layers of a LAN network and which platforms fit into each of the layers.

4. Figure 1-1 Core/Distribution/Access Layers
In Figure 1-1, notice that all of the Catalyst switches (bar the Catalyst 8500)
can be used as an access layer switch. Most commonly, the access layer
function is left to the switches up to the Catalyst 4000/4500 series; however,
many larger networks use the Catalyst 5000/5500 and Catalyst 6000/6500
switch as a wiring closet switches, because they can provide very high port
densities. When this happens, the high-end switch is normally providing
distribution layer functionality as well.
Cisco Catalyst Switch Platforms
Although Cisco Catalyst switch platforms are available, each of which are
suitable for different switching environments depending on the size, complexity,
features required and of course cost. In this section, each of the Cisco Catalyst
switch platforms that are available for purchase and not considered legacy
switches are described (i.e., the platforms highlighted bold in Table 1-1). This
includes the following switch platforms:
Catalyst 2950/3550 family
Catalyst 3550/3750
Catalyst 4000/4500
Catalyst 6000/6500
NOTE
The Catalyst 8500 switch is not discussed in this section because the
Catalyst 6000/6500 switches now outperform this switch.