Could not open ssl 443 port server - linux

Question

I have an external server that hosted in dreamcompute
Which it is can consider as virtual private server (vps)
I have test out using: https://ping.eu/port-chk/
the results:
xxx.xxx.xxx.xxx:443 port is closed
xxx.xxx.xxx.xxx:80 port is open
xxx.xxx.xxx.xxx:22 port is open
I have check my server port is open in linux:
username#server:~$ sudo ufw status
Status: active
To Action From
-- ------ ----
80/tcp ALLOW Anywhere
443/tcp ALLOW Anywhere
22/tcp ALLOW Anywhere
3306/tcp ALLOW Anywhere
80/tcp (v6) ALLOW Anywhere (v6)
443/tcp (v6) ALLOW Anywhere (v6)
22/tcp (v6) ALLOW Anywhere (v6)
3306/tcp (v6) ALLOW Anywhere (v6)
I'm able to access the web server internally by
http://localhost/
https://example.com/
http://example.com/
which all of them I set an index.php with a code:
<?=phpinfo()?>
From my experience, it was my router firewall problem, but I don't have the control to do it.
Maybe it was my dns or something else ?

Answer 1

Steps you need to do to check your port :
verify that you can connect from your local machine... you can just telnet to port 443, both on localhost (127.0.0.1) as well as on your machine's IP address.(You have already done this what I saw.) You should at least get an answer (ie. verification that there is a listener on that port).
Just for an example:
$ telnet 127.0.0.1 443
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused
This confirms port is listening
$ telnet 127.0.0.1 443
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
^]
telnet> quit
Connection closed.
We can also do by checking NETSTAT
$ netstat -antl | grep 443
tcp 0 0 127.0.0.1:52421 127.0.0.1:443 TIME_WAIT
tcp6 0 0 :::443 :::* LISTEN
For SSL we can use openSSL
$ openssl s_client -connect 127.0.0.1:443
CONNECTED(00000003)
...
You may have to open and/or forward the address on your router or network firewall.
Hope it works fine!!
If not tell us, we will work on more solutions!