Okay, sorry for double post, but here's an update:
I haven't managed to talk to my friend again yet, but I decided to run a test on my computer.
First, I opened two B3Ds, one with the client, one with the server. I ran the server, and as the client tried to connect to what I thought was my IP (the one I used testing with my friend). This caused my computer to think for a while, and then fail. Then I tried using the IPConfig IP (on the client) and it connected perfectly! So I assume this means that once my friend has this new IP, the problem should be solved?
I haven't managed to talk to my friend again yet, but I decided to run a test on my computer.
First, I opened two B3Ds, one with the client, one with the server. I ran the server, and as the client tried to connect to what I thought was my IP (the one I used testing with my friend). This caused my computer to think for a while, and then fail. Then I tried using the IPConfig IP (on the client) and it connected perfectly! So I assume this means that once my friend has this new IP, the problem should be solved?