Cisco Catalyst 2950 Switches
The Catalyst 2950 line is an older line of Cisco switches that provide a basic managed switch platform. They provide most (if not all) of the layer-two specific features that are needed to pass an associate level exam. The 2950 switch line was separated into two types of software: Standard and Enhanced.
The standard version offers all common layer-two functionality for basic operations, while the enhanced version provides additional support for Quality of Service (QoS) and Security filtering. Almost all of the Catalyst 2950 modes are End-of-Life (EOL) and End-of-Support (EOS), but still work perfectly fine with most features as most of them haven't changed for some time.
Some common versions of the 2950 line that are currently available include the WS-C2950-12 (12 FE ports) and WS-C2950-24 (24 FE ports) both which run the Standard version of software. Another common one that was found in a couple of listings was the WS-C2950G-48-EI (48 FE ports, two gigabit interface converter (GBIC) slots) and runs the Enhanced version of software.
Cisco Catalyst 2960 Switches
The Catalyst 2960 line is a slightly newer version of Cisco switches that offer basic switching and some IP services features. While some of the models are EOL, most are still not EOS and some support IOS 15 as well which offers some of the newest feature support. The 2960 line was split into two categories as well: one labeled as LAN Lite and the other labeled as LAN Base. The LAN Lite line of switches was focused on small businesses and smaller branch offices, these switches were basic switching features similarly to the 2950 Standard software lines. The LAN Base line of switches was focused on entry-level to middle-level enterprise locations which typically require a higher level of switch feature support.
When it comes to building a lab the best bet is to find one of the LAN Base switch models as it will provide the best overall investment and usefulness.
One common switch that is cost afforable is the WS-C2960-24TT-L 2960 model switch. This switch offers 24 FE ports and two GE ports for easy connectivity and without the extra cost of GBICs or Small Form-Factor Pluggable (SFP) modules.
Cisco Catalyst 3550 Switches
The Catalyst 3550 line has been a very popular Cisco switch model for some time as it provides some support for layer 3 and some additional feature support. Traditionally this has been enough of a factor to prefer the 3550 over the 2960 line of switches. If the target is to get a switch that supports dynamic routing protocols then the 3550 is the minimum level switch that can be used as these are not supported on the 2960 line of devices. All of the Catalyst 3550 switches are EOL and EOS. Like the previous models, the 3550 line of switches was divided into two different levels of software: IP Base and IP Services.
When running IP Base (also referred to as SMI) software the 3550 is basically equivalent to a 2960 running IP Base software (with a few exceptions); however when running the IP Services (also referred to as EMI) software it would then support dynamic routing and several other IP specific features that are very limited in the IP Base software.
A common model for the CCNA Lab is the WS-C3550-24-SMI (24 FE ports, 2 GBIC ports). It is important to note that even though this version of the switch is an SMI (IP Base) model, the upgrade to an EMI (IP Services) model only requires an IOS upgrade.
Cisco Catalyst 3560 Switches
The Catalyst 3560 line is another popular version of Cisco switch that is very commonly seen in home and enterprise CCNA labs. It is a very versatile lab with support for a number of different features including most of the features that will be needed to study for every certification up to the CCIE (assuming the IP Services (EMI) version of software is installed). Like the previous models, it is possible to find both IP Base (SMI) and IP Services (EMI) version of the 3560 line of switches. Upgrading between these two (on older 3560 models) is easy which also helps.
Two common models seen on the lower cost end include the WS-C3560-48TS-S, and the WS-C3560-48TS-E.