You sure you ain't been VAC banned
Have you also re-checked your nat type has not been set to strict etc etc
Won't be vac as that wouldn't stop rift
it's not ISP as his consoles work something is stopping incoming stuff but only games on his pc's only
still wondering if router might be behide it what consoles u got is it ps3 or 360
Not using a BT Homehub are you?
They can cause havok
Are you sharing your internet connection? try disabling this if so. I started having problems with some games when I had my connection set to shared recently, not sure why.
This is why I use an ethernet cable, anywho glad you got it sorted