Why is port forwarding not working?

Question

network hardware

Hello! I raise a simple web server on the local network on port 80, in the settings of the Rostelecom RT-GM-2 router in the forwarding rules, the following settings are found:
But when you try to contact the external ip address, nothing opens, the ip address is white, everything works on the local network. What could be the problem?

Answer 1

From the local network, you can’t just access the external IP - you need to configure HairpinNAT.
Check from a mobile phone a mobile operator connected to the network (not to your Wi-Fi), for example.