Internet Connection Issue

I recently tried to connect my PlayStation 3 to the internet and ran into some difficulties. I connected the ethernet cable to my PS3 and my modem, but when I tried to do the connection test, it failed due to a "DNS error." I don't know much about computers or any of that, so does anyone know how I can fix this problem?

unplug your modem wait 30sec., plug your modem back in(Power i mean, not ethernet cable), wait 30sec., turn on PS3 and set up again