wireless router

I have a windows 200 advanced server with dhcp reservations. ( I do this to keep computer off the network that are not ours.) Recently, we found out that if you connect a wireless router and clone the mac address of a computer that is in dhcp to the router, a number of computers can connect through the router that are not in dhcp.

any security ideas to help me?

 

Yea 128 bit WEP encryption. And Disable SSID Broadcast. Problem solved.

 

Also,
Is DHCP disabled on the router?

 

The problem is, we don't own the routers. Students are plugging them in and we have no idea when or when. So how can I stop them in DHCP?

 

If all your user accounts are properly passworded they can't get to your stuff even if they backdoor in. Connected maybe but not authenticated so basically non-persons as far as your network is concerned.

If the routers aren't yours, then router abuse/network abuse by students isn't really your problem since they would be abusing someone else's territory..

 

Oh, Ok Sue I follow ya now.

I guess if I was in your position I would not use Win2k for my DHCP server and I would turn off DHCP and do static because it sounds like your creating more work with reservations then with static.
I have never used The server box as a dhcp server because I don't like it but that's just my opinion.
I would use something like http://www.netscreen.com where you can clamp down as hard as you want.

I would also unplug every LAN jack at the patch panel that isnt being used.

 

We are a laptop college and we only allow our equipment on the network. So all they are abusing is our policy. I just had this brilliant idea that dhcp reservations would be the thing, then they brought in wireless routers. It never stops.

thanks