I have spent weeks trying to get this to work. Heres the verdict:
-I have successfully forwarded the 25565 port.
-I can connect myself (But only by using localhost or 127.0.0.1 but not my external IP or internal IP)
-I have disabled firewall.
-Whenever my friend tries to connect he gets 'Operation timed out'. I get the same thing when I try to connect using my internal/external IP.
-In the server.properties file file the IP is set to nothing. When I try to set it to something I get a failed to bind to port error when I try to start the server.
As you can see I have done pretty much everything you can do. I was wondering though, when you connect to a server, does putting the port at the end of the IP help at all? Am I doing anything wrong? Somebody please help!

P.S. Please do not say 'Macs suck!' because that is an invalid observation and is off the topic (This is a support forum, not a war forum).