The Skype Problem

Skype doesn't play well by default with web developers. By default it binds to port 80 (standard HTTP port). It uses this port to listen in incoming communications from other skype users. In addition, Skype sends outgoing UDP packets from these ports.

To disable this you should open skype :

• Go to File -> Options -> Advanced -> Connection
• Uncheck "Use port 80 as an alternative for incoming connections" checkbox
• Stop or restart Skype.

You should be good to go. Your apache/nginx web servers can now bind to port 80 without any issues.

For more information see here.