PS3 internet

So i went out and bought anouther PS3 yesterday, and after a while i tried to get it to work on the internet (so i can play with other players), and it wont connect, i have tried the DNS settings and my network provider said there was nothing they could do, because I wanted to add the machine to the network, i can see, other computers on it, i.e, music files on my sons pc, but i can't connect to internet, any ideas?