I am trying to block all connections to the MySQL port 3306 on our server besides connections from one IP address. I managed to black all the traffic using the rule below through webmin on our server
Reject If protocol is TCP and destination port is 3306
I've also added the rule
Accept If protocol is TCP and source is 188.8.131.52 and destination port is 3306
However no matter which rule is first in the list it will not allow the specified server to connect.