Port Query (PortQry.exe) is a command-line utility in the Windows operating system that you can use to help troubleshoot TCP/IP connectivity issues.

<p>As with any network and internet-capable computing system, many of Apple's services and programs require access to the internet and/or local network using TCP and UDP ports to function properly ...

Test if Firewall is blocking a Port. Check which Ports are being used. Also learn how to check which process or service is using the open port.

Learn how to use netstat commands to watch open ports. Using the &ndash;b, -o, -an, interval, and tasklist commands, you can find IP addresses, port numbers, connections, process IDs and ...

Unfortunately, things are more complicated on the PC and PlayStation 3 - you'll need to open separate TCP and UDP ports, and a lot more of them. But it's not difficult.

Zone transfers take place over TCP port 53 and in order to prevent our DNS servers from divulging critical information to attackers, TCP port 53 is typically blocked.

Scott Reeves shares the wireshark filters that helps you isolate TCP and UDP traffic.