CanyouSeeMe is a free tool to check open ports in your system. This tool lets you scan open ports which may prove security holes to hackers. This tool can also test whether port forwarding is working or not.
Canyouseeme.org is a free online tool which can be used to verify status of a port in your system. Our system goive a similar facility to test open port online. Ports are a kind of channels by which programs can communicate with external world. A malicious program can open a port can communicate to external system or can send information after stealing from your system. To check status of your port you need to enter the ip addres which is automatically picked by this tool and press check button.