Can't get online to work

I just got a PS3 yesterday, but i can't get it online. I have DSL and am using a ****** ethernet cable, but every time i try to connect it says there is an error involving the DSN. Any ideas for what I should do?

Uh do u have a router? or are u connecting ur ethernet directly from ur modem to ur ps3?

Uh power cycle ur modem (unplug 30 seconds then plug back up) keep ur ps3 on. When ur modem is back up on ur ps3 go to settings then network settings, make sure the internet connection is enabled. Go to internet Connection settings and pick custom. wired connection, auto detect, automatic ip adress,do not set automatic dns settings automatic mtu, do not use proxy server, enable upnp then test the connection

any chance the nintendo wi-fi usb connector would work?