Ethernet problem

Two of my roommates and myself have not been able to browse the internet using our apartment complex's ethernet. All three of us have MacBooks. We have been able to connect to the ethernet, but have not been able to use Skype, Firefox, Safari, iChat, etc. We are getting "unable to find server" messages. One of my roommates tried using his old Dell laptop to connect using the same wall jack and same cable, and he connected to the internet and could surf on his first try. We have adjusted our settings to those provided by the internet provider. We have only had trouble once before and none of us have changed our settings since then, so we are in the dark. Thanks in advance.

Additional info:

-We can connect wirelessly
-Using Network Utility, I had 0% packet loss when I "ping"ed
-We get an IP address, but only after a few minutes
-I have tried to use domain addresses, ie http://17.149.160.49 and still no luck

I'll happily provide an other information that might be of help

Thanks again!

Also, it was working yesterday afternoon, but suddenly stopped working while both my roommate and myself were surfing the web.

Hopefully you have you machine set to DHCP and let the MacBook do the connection work. If you are behind a router then the setting for the ISP are built into the router, not your machine. Try to renew the DHCP lease in the Network tab. Last - slide the Ethernet to the top of the connection choices so it connects this way first and perhaps disable wireless to get this sorted out first.

What OS are you working with?

I tried both ideas, but still no luck.

My MacBook runs on Mac OS 10.5.7

Thanks for the help

How about downloading and applying the last combo update for Leopard? Should reset a lot of things on the computer. If this does not work I might suggest an Archive and reinstall of Leopard & Combo. It sounds like a setting is wrong or perhaps your computer has a conflict with the router. Can you unplug and replug the router to reset it?

Apple - Downloads - Mac OS X Updates - Mac OS X 10.5.8 Combo Update