I'm currently in the process of getting a CCNA certification (well, beginning to, anyway) and I'm starting to think about what kind of setup I should have to experiment with and observe network communications. Packet Tracer is useful, but it isn't meant to be a replacement for actual routers and switches anyway. So I'm looking for something that will give me hands-on experience with networking -- something I can experiment with long into the dead of night, rather than being restricted to the routers at school. The problem is that I don't know how to do this effectively without spending a ton of money. There are a few things I know I'm going to want to experiment with -- IOS being one of them -- but I'm sure there are quite a few others I'm not even aware of yet. I would be very grateful if someone could steer me in the right direction with advice about what kind of network devices I should get, and anything else I might need to know about for this kind of project. Oh, and it would be even more helpful if the setup would cost less than $500. I don't have a lot of money to spare.