Check if the ports are configured correctly and try again.
Check if the ports are configured correctly and try again.
Yes, there is a service monitoring that port and it supports ICMP pings and other similar protocols.
Would you happen to know if you're behind a double NAT? (A router plugged into another router) This is a common issue and will cause opening ports to fail. Who is your ISP and what is the service type? (DSL, Coax, Fiber, LTE) Some ISPs won't allow port forwarding and some won't allow it on certain service types like LTE.
Connecting a modem over Ethernet to your PC with AT&N as your ISP
AT&T supports port forwarding, but it depends on your connection type. For instance, if you have an LTE router, installing a SIM card might prevent you from using port forwarding. With coax or fiber connections, you should be able to proceed without issues.
This device doesn't rely on Ethernet. Its model number is what you need to identify it.
From the Amazon listing, this Green "Broadband port" appears to be intended for vDSL. The ONT port seems likely if you have Fiber. It probably supports port forwarding. My thought is that the firmware on the device might be outdated—perhaps AT&T disabled it or there’s a configuration issue.