Is it okay to use a Cisco 2948 for CCNA students, after all it's cheaper to get these switches and they have more features? Wouldn't this be better than a 2950 switch?
CCNA requires the student to be familiar with the IOS operating system, this makes the Cisco 2948 unusable for a CCNA lab as it runs Catalyst OS (CatOS) and there is no way to upgrade the operating system from CatOS to IOS. So while it may have more features, for a pure CCNA lab it's not really usable.
Personally I would also recommend the following equipment (if you are not opting for GNS3):
2 x Cisco 2610XM Advanced Fast Ethernet 128Mb Dram / 32mb flash IOS 12.4 Adv Security
Cisco 1760 Fast Ethernet 64Mb Dram / 32mb flash IOS 12.4 Adv Security
3 x WIC-1T for the two 2600 routers
2 x Cisco ws2950
One thing to bear in mind with the CCNA is that the vast majority of the things you need to play with are trivially done in Cisco Packet Tracer and GNS3 (especially since you can now get a switchport card working in GNS3 now). However, with that said, depending on how you learn, you might prefer to work with a physical setup, and if that's within your budget, go for it.
In any case, I'd definitely recommend against foregoing any sort of usage of PT/GNS3, not least because something like GNS3 can actually be used to augment your lab setup - hook it up to your physical gear and run wild.
Wendell Odom's website has a lot of great info, including lab equipment recommendations for CCNA and CCNP.
If you're wanting to save a bit of money, you can use GNS3 for the routers and then just buy some switches. I have written a few blog posts about how you can connect virtual equipment to physical equipment.
I prefer the virtual router + physical switch approach over the full physical lab as it saves money, energy and power points :) It's also good because you can take your virtual router topologies with you everywhere you go.
One of the best ways to get a lab for the CCNA is to get your hands on a copy of the Packet Tracer utility used in the Cisco Networking Academy courses. It contains the full spectrum of "equipment" and commands you will need. However, I don't know if there's another legit way to get it other than enrolling in the course itself.
One other thing to note as well, if you are on a tight budget, don't worry about an expensive switch that can do QOS and Layer 3 because the CCNA focuses on nothing above layer 2 and nothing really fancy (no QinQ, etc). VTP and (Rapid) Spanning Tree will be about the most "complicated" switching topics you'll have. Given this, a 2950 will serve you well and you can get those for less than $50 a pop on ebay.
I just got my CCNA not more than 2 wks ago, and the only hardware I purchased was a C2950 for $30. Everything else was virtual. Both GNS3 and Packet Tracer are helpful overall, but neither is without its bugs. I preferred GNS3, simply because it's easier to connect a virtual GNS3 network to real hardware (like my C2950), or arbitrary virtual hosts (like Qemu or VMWare guests). But I will say this: doubt instead of trust in the correctness of the simulation software can really slow down your learning.The actual C2950 hardware either worked as expected, or somewhere I made a mistake. But with GNS3 for example, you have to ask yourself whether you made a mistake or the software did.
For maximum reliability, buy the real hardware if your budget allows. Expect to spend a fair amount of time figuring out how to get GNS3 to work, and handling exceptions. But even with the faults of the emulators, it's a good idea to consider GNS3 because it's possible to create all kinds of near-realistic scenarious quickly and cheaply.
For basic familiarity with Catalyst IOS switching, I've often had folks check out the 3550 switch. It isn't capable of certain features (QoS, Private VLANs, etc); however those don't come into play at the CCNA level. 3550's can be had for pretty cheap on eBay, last I checked, under $100.
(Also worth noting: if you have a POE 3550, you have to manually configure access ports as trunk ports for separation of voice/data VLANs)
If you want more functionality and a more recent IOS version, the 3560 can be found for $100-300.
Packet Tracer and GNS3 are highly recommended based on the fact that you can get them at no cost. When using Packet Tracer it is also quite useful in familiarising yourself with what the exams sims are like.
However if you can afford it there's nothing like getting your hands on real kit and getting used to the different physical cables, especially if you don't currently work as an engineer. As the CCNA requires you to know stuff about the kit like how it boots, flash, moving config & IOS files around from tftp etc, then if you have some real kit you can take a look inside and have a go at upgrading the flash for example, which really helps the theory click into place.
2500 series & 2950 Cat switches are probably the cheapest option that will do it but if you are serious about certification and want to go beyong CCNA level then you'll want to consider building your lab for the future. So if you can afford it i'd recommend some 1841's for your routers as they are really reasonably priced nowadays on eBay and then (again if you can afford it) get some 3350 switches which you can then load IOS capable of L3 switching and routing protocols.
My suggestion is that you go ahead and practise a lot with Cisco packet tracer and Gns3 which is more than enough for CCNA level.
Also recently I have completed my CCNA R&S v3.0 certification.
I have gone through whole Cisco 200-125 Books and then started practising scenarios and I have used cisco 2900, 3650, 3700 and 3560 switches.
Better use Gns3 where you'll have a hands on with IOS.