how to port forward BitComet

hi guys i'm using the latest BitComet 1.37 64-bit and i'm having trouble forwarding my port , im using a linksys EA6300 , i started the process by selecting single port forwarding and i entered my ip address , but i cant seems to know what is the external and internal port i tried entering the same listen port that im using but BitComet keeps saying the the listen port is blocked

can someone please help me