Network adapter & Dlink routers
Now I don't know if this is ever going to help someone but here i go last night i disabled Vpn connections on my router then i tried to use rad host with my ps2 it never connected i tried countless configurations when i inserted the adapter utility disk it would connect fine to the internet but never to rad host i even allowed my ps2 to be in the demilitarized zone with no success so if your ever having trouble please unable the vpn connections on your router it might solve your problem as it did mine
within 20 sec of enabling it i was connected
hope this helps somebody