Nothing can connect to my server, acting like it's offline (IIS/Windows)

I'm using IIS 10 and Windows 10, hosted on my PC at home.

The common answers I was able to find on the web don't seem to help me. Permissions are all okay, firewall port 80 is open, app pool is live. I've tried iisreset as well, and the W3SVC-related services are all running. When I bind the server to all unassigned on localhost:80 I can view it from there, but not from the Internet, which means the application runs fine itself.

The log files show nothing suspicious or weird either. At one point they stopped receiving connection requests, and the log just ends. HTTP 200's and then nothing. The event viewer has no errors or warnings related to W3SVC either. My external and local IP's have also not changed.

For the record, this site worked before, and only recently suddenly stopped with no changes. I don't think I did anything, but I guess it's possible? This is really boggling my mind as usually I can find any kind of solution out there, so any help is appreciated. Thanks!

1 Answer

If your site was previously working from your public IP (internet IP), but now no longer functions, and you are sure that your IP's and servers configurations have not changed, it may be an issue with your router. Check your router still has the port forwarding setting in its NAT section to point port 80 to your servers local IP.

Try connect to your IIS Server's private IP using a web browser on another machine on your private network. If this can't connect it must be a configuration setting with your IIS Server, if this can connect it's probably a problem with your router (or maybe even your ISP).

If you can't connect locally, run netstat -a in an elevated CMD window to check port 80 is listening, but in your situation I assume it is since you can connect via localhost. To pinpoint it to being a IIS issue and not firewall/routing issue you could stop the IIS service and run a simple application like PortListener and configure it to listen on port 80, after doing that telnet to your private IP on port 80 from another machine and see if telnet connects.

Additional troubleshooting steps (but potentially unsafe):

1. If you can't connect locally - Disable your servers firewall momentarily and try connect via the private IP.
2. If you can't connect publicly - Disable your servers firewall momentarily and try connect via the public IP.
3. In your router's NAT configuration set all ports to be forwarded to your servers private IP momentarily and try connect via the public IP again.