I have created an account on the school server as instructed by the class notes. I have the shared key and all of that. Part of the assignment is connecting to the VPN from home. I have instructions on how to do it with XP, looks like it would take about 30 seconds, but I don't have XP, only Ubuntu. I figured I would be able to do it with Ubuntu, but I'm hitting a brick wall. I have tried vpnc, but get an error that port 500 is in use, when I try any other port I get an [1]: ISAKMP_N_INVALID_EXCHANGE_TYPE(7)
error. I tried using kvpnc and using different Ipsec connection types, cisco, racoon, freeswan, but I'm not making progress. With Racoon and Swan it says it is connected, but I don't see the network anywhere, and if I just make up an IP and try to connect, it says connected, so it obviously isn't. I've looked around online, and vpnc looks pretty simple to connect, but it won't work for me. Can anyone give me any suggestions?

I don't know about the rest of your problems, but if port 500 (udp or tcp?) is truly busy, you can find out what process is using it by, as root:

netstat -nap | grep 500

where the process name & PID should be in the last column.

Also, you didn't say how you were running this, but I believe you have to be root.