Hosting a web site at home: ISP Blocking port 80?
More ISP's than not will block port 80 nowadays to prevent incoming traffic. Usually they won't tell you they are blocking it and your odds of getting a straight or accurate answer if you call tech support are about 50/50. Some ISP's will allow you to set up a server if you work with them to set it up (sometimes with additional monthly fees, sometimes not). About the only way to find out is to call the various ISP's that serve your area and see what they say. Oh, and call the tech support number, not the sales office. The salespeople will either have no idea or they will just tell you what you want to hear.
For testing, take DynDNS out of the list of possible problems:
- Go to whatismyip.com.
- Try that IP address directly, but: from some other internet connection, like by using Web-Sniffer.
- Try an online traceroute to that address (that will not use port 80, but might still give you some clue).
If that doesn't work, there are many possible causes other than port blocking, like:
- Maybe the port forwarding in the router is incorrect.
- You might be trying to use the DynDNS address (or public IP address) from within your own network, which will likely end up in your router rather than at the web server.
- Maybe (but not likely) you've set up your web server to only bind to localhost, not to any outside requests.
I'm going to reply to this as I've now found the answer.
The problem was with the port forwarding of the router. Due to a bug in the firmware, it would only "remember" the TCP port setting, even when changed to UDP/TCP or just UDP. Following a firmware update I can choose to forward both types of port and it seems to be working. I am surpirsed that the ISP doesn't block port 80, but hey, I'm not going to complain.