I have a Buffalo ADSL Modem/router which I would like to use to share the connection. The first time I plugged the cable into one of the 4 LAN slot. I was able to browse wirelessly but after a few minutes it stopped working and has not worked ever since. Could it be some kind of restriction on their part? Is there any special configuration settings to share my connection in such a way? Note that I don't use any DSL (phone) line here I only have access to an Ethernet cable. When trying to browse Chrome gives me "Cannot load page because the DNS lookup failed".
Unplug the router. Wait ten seconds. Turn it back on. If that doesn't fix the issue there should be a button that resets the router to factory defaults. You will have to hold it for about ten seconds as well.
I don't recommend doing this if don't know how to set up a router. Definitely don't do if the router was provided and set up by your Internet Service Provider. If it was they might have a Username and Password in the Router User Interface that will have to be entered.
If it does and you know the Username and Password and know how to setup the router than be my guest. There is also a chance that the network isn't being broadcasted or the SSID is hidden. If that's the case just go to UI and enable broadcasting or change the SSID to broadcast. Hope this will help you.
I should try resetting it again. This time disconnect the Internet and LAN cables then press and hold the reset for 30 seconds allow it to boot up for 2 minutes then unplug it.
Wait a moment then plug it back in give it 2 minutes to fully boot then attach an LAN cable for the computer to configure it and try getting to the configuration page. By default it may not have any wireless security but probably does have DHCP enabled.