I can SSH via local network.
nmap -p <ssh_port> 192.168.1.xx => <ssh_port> open
But I can't SSH over the internet even port forwarded.
nmap -p <ssh_port> xxxx.duckdns.org or <public_ip> => <ssh_port> closed
And I also have another port forwarding to and it work find over the internet.
nmap -p <cctv_port> xxxx.duckdns.org or <public_ip> => <cctv_port> open
How do I check what is the problems (my ubuntu, router, duckdns or ISP) ? and How to fix it ?
- I contact to my ISP and thay told they doesn't block any ports.
- Now I try using python3 -m http.server 8181 and do port forward but can't access from outside too.