I have a client with a Netgear WNDR3700v3 router. Firmware updated to latest.
An external company gets access to a piece of hardware on site via ports 1023, and 23. This has been working for some months as far as I've been told. Recently they called to say they stopped being able to access their on-site hardware (a monitoring system of some sort).
When I go to the Internet IP address:<port number>, it gives no access. I went to YouGetSignal.com (and a couple of others), and all ports for which port forwarding is configured on the router are showing up as closed. The router's remote access port (8080) is showing up as open, however (as configured).
I have another client who has similar port forwarding issues, and his router is a Netgear as well.
Does anyone have experience with Netgear routers in particular? Or can anyone offer advice? I've been routinely doing port forwarding for nigh unto 15 years, and this has me stumped.