Internet problem

I'm running Panther and I have my Mac and PC both connected to an SMC router connected to a DSL connection. I've been using the internet on both of them with no problem for a while now, until suddenly my Mac just stopped being able to connect to the internet. My PC still conencts fine, and my Mac is still able to connect to my PC on the network. I'm trying to figure out what's wrong but I'm stumped at the moment, my router is the type that holds the ISP login information so all you do is open your browser on your computer and surf the web, so it's not like the password is wrong or anything. My Network prefrences weren't changed before the problem happened either (they were set to Automatic).

Anyone have any suggestions?
Thanks alot in advance.

 

I just tried that, it didn't work.
Yeah, I checked the Network prefrences a while ago they were the same, since then they've cahnged because I've been trying things to fix it.

I'll try resetting the router.

 

I don't have wireless, I just fixed it though I didn't have any DNS servers in the prefrences, and I opened the SMC config thing on my PC and checked the DNS numbers in there and plugged em in.

Thanks for the speedy replies anyway guys.