As I can, configure the firewall of ubuntu server for the server to accept connections of the terminals through PostgreSQL port 5432 - linux

Question

Configuration: Server: Ubuntu server 16.04 LTS using webmin
Terminal: Windows 7 Using PgAmin III
I was unable to establish the connection between my terminal and my server through pgAdmin III on port 5432.
On my server I added:
in file postgresql.conf I edited
in #Connection Settings
listen_addresses = '*'
in file pg_hba.conf I added
in #IPv4 local connections
host all all 172.x.x.x/32 md5 //this is IP Terminal (Hidden x)
I checked the port, this is 5432 default and user is postgres
When I try to establish the connection on PgAdmin III:
Host: //My Server IP (Ping console successful)
Port: 5432
username: postgres
password: //My password
Show me the following message:
Server doesn't listen
The server doesn't accept connections: the connection library reports
could not connect to server: Connection refused (0x0000274D/10061) Is the server running on host "Mi SERVER IP Hidden" and accepting TCP/IP connections on port 5432?
If you encounter this message, please check if the server you're trying to contact is actually running PostgreSQL on the given port. Test if you have network connectivity from your client to the server host using ping or equivalent tools. Is your network / VPN / SSH tunnel / firewall configured correctly?
For security reasons, PostgreSQL does not listen on all available IP addresses on the server machine initially. In order to access the server over the network, you need to enable listening on the address first.
For PostgreSQL servers starting with version 8.0, this is controlled using the "listen_addresses" parameter in the postgresql.conf file. Here, you can enter a list of IP addresses the server should listen on, or simply use '*' to listen on all available IP addresses. For earlier servers (Version 7.3 or 7.4), you'll need to set the "tcpip_socket" parameter to 'true'.
You can use the postgresql.conf editor that is built into pgAdmin III to edit the postgresql.conf configuration file. After changing this file, you need to restart the server process to make the setting effective.
If you double-checked your configuration but still get this error message, it's still unlikely that you encounter a fatal PostgreSQL misbehaviour. You probably have some low level network connectivity problems (e.g. firewall configuration). Please check this thoroughly before reporting a bug to the PostgreSQL community.