Failed to bind to port problem help

[cibastian]

Launcher/Pack version: latest, 2.1.1

OS: Mac

Version of Java: JRE 7

Description of the problem: i have a fail to bind to port when i am trying to set the server to use my external ip address...

Pastebin: http://pastebin.com/WhpetwDF

[jakj]

Likeliest issues are 1) something is already using that port, 2) you're accidentally running the server twice so it's conflicting with itself, or 3) your firewall, gateway, router, or proxy is not allowing you to bind.