Great suggestions from Knack there, with that kit you could definately make some headway with the concepts you learn on the CCNA (your school probably won't shell out for your class to do the actual certification though, I know mine didn't!). You could do allsorts with it, I can think of a few ideas off the top of my head to show some basic hands-on demonstrations of how networks work and behave.
Network Standards:
- Knacks suggestion of using home-made crossover cables for your mediums is a good one as with the onboard ethernet ports and the T1 cards, you could show how the different standards use different pin-outs and the same RJ-45 connector (but how the principles are the same/similar). Also how crossover cables differ from straight through and why, and how most modern networking hardware autodetects the cable configuration.
- Even cooler if you guys could get taught how to make the cables up yourselves, it's a pretty useful skill to have, even for non-networkers!
- If you can get some E1/T1 Co-Axial/BNC cables, you can see how cat5e cables and wireless didn't always rule the LAN world.
IP Addressing:
- A lot of this is theory, but with some hardware to play with you could do things like set up 2 machines with no DHCP (linux is really cool to do this on as you get to see whats actually happening) and manually configure the network adapters statically (with IP's and Subnet Masks which you and your class have worked out beforehand. All you need for this is a switch or hub and the machines I imagine you already have - plug them all into your hub/switch and pair up with someone else in the room, figure out your IP address and subnetting scheme (not classful, use VLSM because it's way more interesting) between yourselves and configure the machines, and see if you can ping each other.
- Variable Length Subnet Masking can be a bit scary at first, but it's quite simple as long as you think about it the right way - and it's a strong skill to have when going into networks! This might be a bit dry for you though.
Transmission Basics
- I guess by this you mean looking at signals and stuff, this is kind of hard to demonstrate without scientific equipment like oscilloscopes and stuff. This one will probably have to stay on the chalkboard, I'm afraid. Having said that, I learned a good few lessons about how fibre-optics work by just working on them, but I imagine this will be WAY too expensive.
Network Protocols
- Again, this is a bit tricky to clearly demonstrate physically, but you could do things like a little set up to just send pings and traceroutes constantly (programs like the free WinMTR:
http://winmtr.sourceforge.net/ let you do extended traceroutes and pings with a nice GUI) and have your teacher explain how those 2 commands work, i.e. the ICMP protocol, to show how important information like Round Trip Time etc... is used. If you had something like the SmartBits traffic generator boxes (expensive) you could show how packets are formed and even how things like WRED work, but that's probably a bit too indepth.
Subnetting
- This is basically just part of the IP Addressing one, you'd demonstrate it at the same time. What you might want to do is set up a simple routing protocol like RIP up on the 2 2600's to show how connected network information is shared around the network, and why subnetting is very important to this.
Networking Hardware
- Understanding the roles of each type of networking gear is pretty easy when it's all laid out infront of you, I can't think of a better way than to set up some of the CCNA lab type experiments with the gear Knack suggested.
Networking Security
- This could be a bit expensive to show with dedicated hardware, and I'm pretty sure a PIX firewall or whatever is way overkill. What you could do though, is show how you can use Access Lists to control user access and network access on specific ports, etc...
- NAT is an important thing to think about when you're talking security, so an explaination/demonstration of how that works and how it helps protect you from outside threats would be cool.
I can't really think of much else, if your teachers don't respond too well to 'buy a load of cisco kit', I'm sure we can come up with some cheaper (but not nearly as good!) options.
- Dag