linux internet connection

[Ned]

Hi,
I am currently downloading the DVD images because, apparently, I cannot install from network.
Can anybody tell me why is there no connection to the internet?
It's cable high speed, and it works on win over the modem. I chose to config the network manually, entered the ip, netmask, default gateway, name server, host name, and the domain as it is provided to me by the cox.net. Still, doesn't work. I called their tech support, and they said that their modems don't support linux, which I find ridiculous at the least since 85% of the internet servers run on linux. Could someone enlighten me on this very topic since I am a programmer primarily, and my knowledge of networking = 0?

Many thanks in advance!
ned