OS X Mavericks: Check for open TCP ports
TCP/IP communications between your computer and other computers on the Internet pass through numbered logical ports on each computer.
Knowing which ports are open on your computer can help you assess the security of your system or troubleshoot connection problems.
- Open Network Utility and click Port Scan.
- Type your IP address, then click the Scan button.
To find your IP address, choose Apple > System Preferences, click Network, then select the a network service, such as Ethernet or Wi-Fi.
To see more information on ports or to see a list of ports used by specific software, visit the Apple website at www.apple.com, click the Support tab, and search for “well known tcp udp ports.”