I know, many a port forwarding question has been asked before... But I've been struggling with my router for days now, wasting too many hours, reading everything I can find online and failing to make any sort of progress. You are my last hope!! :D
My setup is simple: a Raspberry Pi (running Raspbian Stretch) behind a ZTE Speedport Entry 2i router. I want to be able to SSH into my Pi from outside, but also to run a little web server on it.
I made sure my Pi firewall (ufw) has ports 22 and 80 open and listening. No other firewall installed (I can SSH into the Pi from another computer on the same LAN without any problem).
I have found not 1 but 2 tutorials instructing precisely how to forward ports on a ZTE Speedport Entry 2i: https://portforward.com/zte/speedport-entry-2i/ and https://www.youtube.com/watch?v=XF4ZH9FU1ew. They recommend two slightly different ways of setting up the WAN IP Host Range (one says "Make sure that WAN Host IP Range is set to 192.168.1.1 ~ 192.168.1.1" and the other recommends leaving the range as 0.0.0.0 - 0.0.0.0 — I tried both solutions).
No matter what port I try forwarding to my RPi's IP, nothing goes through. Using https://www.ipfingerprints.com/portscan.php, I always get: "Host is up. State: Filtered."
I think the IP address I'm getting from my ISP is a public one (at least it doesn't start with 10 or 176).
I thought it might be my ISP blocking port forwarding for some reason. But even when I forward, say, port 8022 to port 22, still nothing happens.
In fact, even when I enable DMZ towards the Pi, nothing is forwarded.
So it seems that some kind of firewall is creating mischief somewhere. There is a firewall installed on the router; I set it to the lowest security level, which says "WAN host can directly access LAN host, but cannot access device itself (except echo-request)."
I tried all the advice listed there (http://www.pcwintech.com/common-problems-fixes-port-forwarding), including rebooting my router, but to no avail.
Any advice would be most welcome!