ISPconfig Multiserver "fake" service offline

Hi,

I installed ISPconfig on 2 separate servers, 1 for WEB/FTP, the second just for MySQL (planning on adding more servers for DNS management).

The two servers are connected to each other in the intranet and only the first server has endpoints in internet (ports 8080, 80, 21). To connect the second server I used the internal IP address and it is working like a charm.

Only problem is that according to ISPconfig MySQL is offline on the secondary server while it is actually working.

My understanding is that ISPconfig tries on monitors the port 3306 but I don't understand on which network interface:

Code:

tcp        0      0 *:mysql                 *:*                     LISTEN      2197/mysqld
tcp        0      0 db.mydomain.net:53793 web.mydomain.net:mysql TIME_WAIT   -

I am positive that the secondary server is listening on the port 3306 but in the intranet.

Code:

10.0.1.5        db.mydomain.net db
10.0.1.4        web.mydomain.net web
#138.91.124.155 db.mydomain.net

I saw in "System > Server Config" that the servers are both listed with their public IP address. If ISPconfig is monitoring against the public IP I understand it might fail as the firewall is currently blocking all connections to the public IP of the secondary server.

EDIT: additional info, status of services is constantly updated so we can exclude that the message is old.

Any hint?

Thanks

 

No hint on how the monitoring works?

Thanks in advance!