Ok, now you're just abusing buzz words
They're at a school so the school it going to have one NATd internet connection. Without a client installed on the PC, you aren't going to get their PCs IP address. Even if you did I'd wadger many of us have the same address. Getting the subnet is useless. They're all going to be 255.255.255.0 unless they are super subnetting. Then you still only get 255.255.252.0 etc. WAP and WEP are two different ways to "secure" a wireless network. Both suck mighty nards but WEP is god awfull.