IPv6 Firewall- One Port Will Not Forward

[GHammer]

I have 384.16 b1 running on my 86U.
I have several ports forwarded to a server.
All but a single IPv6 forward work. One refuses to forward.
This is a test from another machine to the server:

root@tester:~# nc -zv 2601:19b:4800:2121::1e72 443
Connection to 2601:19b:4800:2121::1e72 443 port [tcp/https] succeeded!
root@tester:~# nc -zv 2601:19b:4800:2121::1e72 8883
Connection to 2601:19b:4800:2121::1e72 8883 port [tcp/*] succeeded!
root@tester:~# nc -zv 2601:19b:4800:2121::1e72 8096
Connection to 2601:19b:4800:2121::1e72 8096 port [tcp/*] succeeded!
root@tester:~# nc -zv 2601:19b:4800:2121::1e72 9001
nc: connect to 2601:19b:4800:2121::1e72 port 9001 (tcp) failed: Connection refused

A test from a remote location:

Using https://www.ipvoid.com/port-scan/
73.238.136.25
9001
 TCP Open
2601:19b:4800:2121::1e72
9001
 TCP Closed

As far as I can determine, there is no issue on the server, firewall, iptables, etc.

root@srvr:~# ufw status
Status: inactive
root@srvr:~# systemctl status iptables-persistent
Unit iptables-persistent.service could not be found.
root@srvr:~# systemctl status iptables
Unit iptables.service could not be found.

Any ideas?

 

[RMerlin]

Keep in mind that IPv6 is not NATed, it's routed. Therefore, you don't forward ports, you open them - and the IP must be that of the target computer, not of the router itself.

You will also want to make sure that your server software is bound to that specific IP - it might possibly only be bound to the IPv4 address by default.

 

[GHammer]

Keep in mind that IPv6 is not NATed, it's routed. Therefore, you don't forward ports, you open them - and the IP must be that of the target computer, not of the router itself.

You will also want to make sure that your server software is bound to that specific IP - it might possibly only be bound to the IPv4 address by default.

Thanks. As the testing shows, I have opened the ports as other traffic gets through.

However, it is an issue with websockets on Linux Mint not having been compiled with IPv6.

Just discovered that and looking for a cure.