I the network through a router port mapping, mapping to a service on this computer (such as: 192.168.1.42:3306, MySql) then this is normal access MySql,
And I (192.168.1.42) on this computer to install a docker_nginx, configuration:

Server {
Listen, 9200;
Server_name loca.home.com;
The location/{
Proxy_pass http://192.168.1.99:9200;
Proxy_set_header Host $Host: $server_port;
Proxy_set_header X - Real - IP $remote_addr;
Proxy_set_header REMOTE HOST - $remote_addr;
Proxy_set_header X - Forwarded - For $proxy_add_x_forwarded_for;
}
}
Then I input on this computer: 127.0.0.1:9200, can be normal access to another computer (9200) 192.168.1.99:
Separately, the router port mapping (outside net - & gt; 192.168.1.42:3306)
Nginx proxy forwarding (192.168.1.42:9200 - & gt; 192.168.1.99:9200)
All is normal,
At this time, I'm from outside network, access to port 9200, but they cannot take effect (from outside the network - & gt; 192.168.1.42:9200 - & gt; 192.168.1.99:9200) this paragraph cannot complete consult
Consult the possible reasons (probably has a way of thinking or)
Should from which aspects to think, how to test for possible problems?