What is Port Scanning / Testing
In modern day networking, the Transport Layer of the Internet Protocol Suite, like Transmission Control Protocol (“TCP”) and the User Datagram Protocol (“UDP”), use a numerical identifier for the data structures of the endpoints for host-to-host communications. Such an endpoint is known as a port and the identifier is the port number. The Internet Assigned Numbers Authority (IANA) is responsible for maintaining the official assignments of port numbers for specific uses.
The complete list of these Port Numbers is available at Wikipedia.
Port Scanning is the technique to probe a network host for open ports. This is often used by administrators to verify security policies of their networks and by attackers to identify running services on a host with the view to compromise it. To portscan a host is to scan for listening ports on a single target host.
How to Do Port Testing
True to its name, Simple Port Tester is a UDP or TCP/IP Port Scanner to help users test if their ports are open with just a few clicks. It has been developed for the not-so-experienced network administrators, which do not want to get trapped in the complexities of advanced Port Scanning and Monitoring techniques.
The trick with testing if your port forwarding is working is to have something on your computer actually listening on the port. If nothing is listening on the port the test will fail no matter what. This program will open the port, listen for the connection and help ensure a proper and reliable test as to whether or not your port forwarding is working.
Download, install and run it. Put in the port you wish to test and hit begin, that’s it!