Why does port forwarding not work even though I configured it?
Common causes are CGNAT/double NAT, wrong internal IP, local firewall, wrong protocol/port, or testing from inside without NAT loopback.
Public WAN; reservation; listening service; firewall; protocol.
Security/network engineering.
Show the technical detail
On a managed Wi-Fi plan
Verify each layer and use least privilege.
On another provider's router
ISP may require public IPv4.
What to be careful of
Never expose admin interfaces or unsafe IoT services.
Where this comes from: Official · see the original source ↗ · Draft—technical review · checked 17 August 2026