I'm trying to make a simple P2P chat application (in VB 2010 - just for practice) that uses UDP. I've finished the application, and I can send messages locally by sending on 127.0.0.1.
I've sent the executable to a buddy of mine to help me test it, but I'm unable to receive anything. My initial thought was that this was a NAT issue, and that I would have to employ an introducer to punch through my NAT. To keep things simple for now, I decided to just bypass my router entirely and connect directly to my modem in order to test this.
Still no dice. Just to be clear, I gave my friend my IP (96.55.XX.XX ... not a local address) and the port that my client is listening on.
Even if my friend is behind a NAT, shouldn't I still be able to receive packets? If I tried to reply to his messages, that could obviously be a problem if he's behind a NAT. I'm strictly talking about a one-way communication here though. Him sending messages to me.
I can't see it being a firewall issue either, since I've added a rule for my application in my firewall settings. Can anyone think of a reason as to why I wouldn't be able to receive his messages, despite the precautions I've taken?
Thanks in advance!