I've also dealt with this myself some time ago and I managed to fix it, but doing the same troubleshoot tips that [i]I[/i] did for myself isn't solving [i]his[/i]problem and I'm out of ideas.
- His [i]UPnP Router External Port[/i] number is always changing, and making the Windows Firewall Outbound and Inbound rules doesn't seem to be working because of it.
- His router doesn't have any Port Forwarding capabilities, so we can't even open the specific ports that need to be opened for D2.
- He has rebooted his router/modem numerous times and it's not fixing anything.