MariaDB MySQL remote inbound connection issues ?

Is remote mysql server also running Centmin Mod LEMP stack ? Did you restart CSF Firewall after making /etc/csf/csf.conf changes ?

Code (Text):

csf -ra

Centmin Mod LEMP stack installs CSF Firewall out of the box, so to be able to remotely connect to external servers, you need to whitelist and allow the remote IP address see the info below:

• Getting Started Guide step 4
• centminmod.com/csf_firewall.html
• CSF - CSF Firewall info see 2nd post specifically for port whitelisting per IP

 

oh then you need to whitelist 3306 port on TCP_IN not TCP_OUT comma separated list to allow remote web server to connect inbound to TCP port 3306 on centmin mod/csf firewall protected server

but better why is just to whitelist web server IP in CSF Firewall without whitelisting TCP_IN port 3306

 

or even better finer grain control over white listing one source remote web server IP + TCP in 3306 port specifically https://community.centminmod.com/threads/csf-firewall-info.25/#post-3731

example in /etc/csf/csf.allow where source ip (remote web server) = 11.22.33.44

Code (Text):

tcp|in|d=3306|s=11.22.33.44

 

I'd get in habit of post new threads for new topics in correct forums as this helps all other members and readers long term

For custom php settings read centminmod.com/phpfpm.html#customphpini. You might want to create /etc/centminmod/php.d/b_customphp.ini to override centmin mod defaults at /etc/centminmod/php.d/a_customphp.ini and restart PHP-FPM. Such changes will persist when doing centmin mod upgrades.

Also outlined in Getting Started Guide Step 17

 

Not advisable security wise depending who has access to the remote source server. Just giving the server enough access to a particular port(s) is just safer especially if you're not the only person who has access to the remote source server.