Posted 15 September 2010 - 08:03 PM
Yep, you can do that.
I am assuming your wireless is already set up, if not, do that first.
Connect to one of the four LAN ports and log in to the management screen. Click the WAN button on the left side. Select "Static IP Address" and enter an address of 10.10.10.10 and mask 255.255.255.0. Save it.
Now go to the LAN button on the left. Set the LAN IP address to 192.168.x.1 where x is some number OTHER THAN what your PC gets when you connect to the building Ethernet (I usually use 192.168.101.1). Write this number on a piece of tape and stick it on the bottom of the router. You will need it to ever talk to the router again, and you will have to set your PC to the same subnet (192.168.101.2, for instance) if you need to talk to it. DO NOT SAVE OR RESET YET.
Go to the DHCP tab on the left. Set the DHCP Server to Disabled.
NOW you can save and reset the router. Put a piece of tape over the WAN (or Internet) plug on the back. You won't use it, and need to remember not to try. Plug the building Ethernet into one of the LAN ports. Your wireless should be online, and you can also use the other three LAN ports for connectivity.