How to enable a specific port on Ubuntu version 22 so that it is accessible to outside world?

How to enable a specific port on Ubuntu version 22 so that it is accessible to outside world?

I am already logged into the server through ssh using port 22 and able to successfully execute all the commands.

I have enabled the ufw firewall and also enabled ports 22, 80 and 22786.

Both 22 and 80 are fine and accessible but not able to access 22786 from outside world.

Do I need to change some other firewall settings to enable port 22786 ?

admin@prod:~$ sudo ufw status numbered

Status: active
     To                         Action      From
     --                         ------      ----
[ 1] 22786                      ALLOW IN    Anywhere
[ 2] 22                         ALLOW IN    Anywhere
[ 3] 80                         ALLOW IN    Anywhere
[ 4] 22786 (v6)                 ALLOW IN    Anywhere (v6)
[ 5] 22 (v6)                    ALLOW IN    Anywhere (v6)
[ 6] 80 (v6)                    ALLOW IN    Anywhere (v6)

admin@prod:~$ sudo netstat -plunt

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      1619/nginx: master
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      834/sshd: /usr/sbin
tcp        0      0 127.0.0.1:6010          0.0.0.0:*               LISTEN      927/sshd: admin@pts
tcp        0      0 127.0.0.53:53           0.0.0.0:*               LISTEN      784/systemd-resolve
tcp6       0      0 :::80                   :::*                    LISTEN      1619/nginx: master
tcp6       0      0 :::22                   :::*                    LISTEN      834/sshd: /usr/sbin
tcp6       0      0 ::1:6010                :::*                    LISTEN      927/sshd: admin@pts
udp        0      0 127.0.0.53:53           0.0.0.0:*                           784/systemd-resolve

I installed Nginx manually and was able to access it using http://ipaddress

But when I check through this online tool (https://www.yougetsignal.com/tools/open-ports/), it shows both 22 and '80' ports are enabled but 22786 is closed.

22 port was already open when I got this host and 80 got enabled after I installed Nginx and added it to ufw using sudo ufw allow 80 command. I used sudo ufw allow 22786 command to enable this port too but no luck.

It is important whether there is an application on the server that listens on TCP port 22786.

Please, attach here a reply from the netstat command on your server.

sudo netstat -lntp

You should also see port 22786 in the list of listening TCP ports.

If the netstat is missing, install net-tools.

sudo apt-get update
sudo apt-get install net-tools

You can try netcat nc as a replacement listening application if you are missing the necessary application on port 2276 for your test.

sudo nc -l -p 22786 -k

In a terminal window other than the one where the nc runs, repeat the netstat.