Can connect to Port-Forwarded IP on my WiFi, but not any other network

I port-forwarded my external IP to my IPv4, and it works perfectly on my WiFi network, but if I change the active network on my device, I can't access it. I am for sure that both IPs are correct and it is not a Windows Firewall issue either. There are no other programs conflicting with it because I have just wiped the host computer. What can I do?

3 Answers

I just had this same issue with the same router that you are using in your screenshot (or at least the same software). If you click "(more)" at the top of the screen you will see there is an option to leave the external ip as 0.0.0.0 to forward all external traffic and leave the external ports at 0 if you don't need to switch them in this process. This took me almost a year of on-and-off troubleshooting and hopefully it will help you. As soon as i found these options, it began working as expected from outside my home network as well as inside.

I think you are accessing your external ip from your local area network. You can't access your port forwarded external ip from inside. Port forwarding only for accessing from outside.

Two issues you might be facing:

1. I'm not sure what you mean by "another network". A port forwarding rule only exists for the router on which you defined it. So if you define a port forwarding rule on your router and then switch to another WiFi network, the rule will not work because your computer is no longer using the router where the rule is defined.
2. A port forwarding rule is IP address specific and does not work well with DHCP. If you then connect your laptop using the Ethernet port, for example, then your internal IP address will be different and the rule won't work. Also, both your internal and external IP addresses may change at any time because of DHCP. You can control this on your internal network, but there's nothing you can do about your ISP's policy.

How to do it right:

1. Always use DHCP reservations (if your router supports that feature) or static IPs on your computer. Give EACH interface on your computer a different address and make two identical port forwarding rules; one for each. This will eliminate the DHCP problem.
2. Use a dynamic DNS service such as No-IP or DynDNS to map your external IP address to a DNS name. These services offer an agent that you download to your computer that will keep your public DNS record in sync with the IP address your ISP gives you, so you can always reference it by name from anywhere on the Internet. This will solve the ISP DHCP problem.

You will need to do this for each network you attach your laptop to (assuming you have control of those networks).