Open TCP Port Not Recognized By Router

I have designed over a dozen boards that use the W5500 for TCP communications over a LAN. I recently tried to access the W5500 on a board which was configured in TCP mode and was in the Listen state. If I use a browser (like IE11) over the LAN, there is no problem connecting to port 80 of the W5500. However, if I set up my Netgear FV318 router for port forwarding to port 80 of the same W5500, the router does not recognize that the port is open!!

I spent considerable time (and money) working with the tech support people at Netgear to verify that the problem was with the W5500 and not the router.

I further confirmed this problem when I attempted to connect to the W5500 through the LAN using an ESP-8266 Wi-Fi device. The ESP-8266 successfully connects to an IP camera on the LAN but fails to connect to the W5500 on the same LAN.

I would like to find someone who has anyone successfully used port forwarding with the W5500 as the target device.

As long as you were talking to support, you most probably have much more technical information about the incident. Can you share it please? Did you investigate packets and their flow?

Please check steps below.

  1. If you don’t use DHCP in a target, change to DHCP.
    And then check the status of target in a router.

  2. After No. 1, if a target isn’t recognized in a router, you must have the connection of TCP between a target to external IP once. In this case, it doesn’t matter DHCP or Static IP. Please check the status of target in a router.

  3. After No.2, if you can recognize a target in a router, and then please use port forward function in a router.

In my case, I used a WIZ550SR-EVB and ipTIME-A2004plus router. I succeeded.