CanYouSeeMe.org - Open Port Check Tool
This page will serve as a free utility for remotely verifying a port is open or closed on your router. It will be useful for users who wish to check to see if a server is running or a firewall or ISP is blocking certain ports or verify network security. If you want to do website hosting on your own or run your own ip camera behind your router it will also helpful.
Website hosting can be expensive. You can save yourself the cost by using the tool and then finding cheap domain names to point to your own server.
You might also need to use this tool to verify that you can connect to your ip camera. Once you have your ip camera setup, configure port forwarding on your router and then verify it works!
Most residential ISP's block ports to combat viruses and spam. The most commonly blocked ports are port 80 and port 25.
Port 80 is the default port for http traffic. With blocked port 80 you will need to run your web server on a non-standard port.
Port 25 is the default port for sending and receiving mail. ISPs block this port to reduce the amount of spam generated by worms on infected machines within their network.