Open Port Checker
To test for open ports enter your local/remote IP address and select a port number on the right. Your public IP is preloaded.
What is This Tool?
It is a simple free port forwarding checker that can be used to find out whether a particular port is open or blocked by a firewall.
Although port numbers are essentially abstract certain applications occupy common port numbers. I have listed the most popular ones above which you can click to check against your host.
On a router it is typical that most ports are blocked to prevent malicious activity. Your router is essentially a proxy between you and the internet so the act of allowing a program or game using port or range of ports to pass through is known as port forwarding.