Why is port 80 not opening?

Question

Computer networks

Hello. Problem opening port 80 . All the others open up just fine .
I changed the modem, tried from another PC to another OS (Linux), turned off the firewall, all to no avail. I set up DMZ, port triggers and everything I tried. I checked with the provider, they do not block.

Apache server, scanning ports with PF port checker.
But port 80 should be open, but http is on port 80

There is a connection inside the local network

Answer 1

Wanguyu that port 80 is occupied by the web muzzle of the router. Occupy any other port on internal 80 - if it works, then I guessed right.