Member Avatar for Yorkiebar14

Hello,

I really need help getting my ZyXEL router to forward the ports I need.

I have tried going to Network > NAT > Port Forwarding and setting up the correct information, doesn't work. I've tried disabling the firewall on Security > Firewall > Active Firewall (unchecked), doesn't work. WAN to LAN and LAN to WAN connections are all permitted, I've tried disabling my PC's firewall and it still doesn't work.

Portchecktool.com (given from no-ip.org which is what I'm trying to use) says that all my ports are blocked except the ones in use by the other services (80, 8080, etc.).

Any help is highly appreciated,
Thanks!

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  • Latest Post Latest Post by JorgeM

Dani AI

Generated

Quick, focused checklist that addresses gaps not covered yet (builds on ’s setup attempts and ’s note about client firewalls).

  • Ensure the target device has a fixed LAN IP (use a DHCP reservation or set a static). Forwarding rules must point to that exact address.

  • Confirm the service is actually listening on the LAN interface (not just localhost). On Windows:

    netstat -ano | findstr :<port>

    On Linux:

    ss -tulpn | grep :<port>

    Replace <port> with the port number being forwarded. Look for 0.0.0.0 or the LAN IP, not 127.0.0.1.

  • Verify the router’s WAN IP is a public address. If the WAN IP is in 10.x.x.x, 172.16.x.x–172.31.x.x, 192.168.x.x or 100.64.0.0/10, the ISP is using carrier-grade NAT and normal port forwarding will fail.

  • Test from outside your LAN (mobile data or a friend). From an external host try:

    telnet <your_public_ip> <port>

    or

    nc -vz <your_public_ip> <port>

    Testing from inside the same LAN can give false negatives if the router lacks NAT loopback.

  • Temporarily put the host in the router’s DMZ as a diagnostic to see if it becomes reachable; check the ZyXEL’s firewall/logs for dropped packets. Don’t leave DMZ enabled long-term.

  • Confirm forwarding rule matches protocol (TCP vs UDP), and disable UPnP while testing to avoid rule conflicts.

If the WAN IP is carrier NAT or the ISP blocks that port, request a public IP from the ISP or use a VPN/remote VPS reverse tunnel to expose the service. Keep services patched and avoid long-term DMZ exposure.

Member Avatar for JorgeM

Im not familiar with this router, but did you make sure that the host you are forwarding to does not have a client side firewall turned on? if it did, even if you set up port forwarding correctly, those internet services you mentioned to check the ports would show closed if the endpoint does not respond on that port.

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