CSF is one of the best opensource firewalls that using in most of the hosting servers like cPanel and Directadmin . Also it is one of the best firewall for installing Zimbra Mail server . This documentation will help you to configure the CSF firewall in a Zimbra Standalone installation server.
Before starting the installation , you may need to read the documentation available on http://wiki.zimbra.com/wiki/Ports , this will help you to get a quick understanding of ports that required to open in a Zimbra server.
Install CSF :
You can download CSF from http://configserver.com/cp/csf.html and install it . After that open the CSF configuration and enable the following ports,
TCP_IN = "22,25,53,80,110,143,443,465,587,993,995,7071"
TCP_OUT = "22,25,53,80,110,113,443,465,587,993,995,7071"
Now you need to open the file /etc/csf/csf.pignore and add the following zimbra packages paths.
This will help to white list these binaries in CSF
Now you can start the CSF as follows and test it.
# /etc/init.d/csf start
You may need to test the mail server and its functionalities . After that you can disable the testing mode in csf.conf and reload CSF. You can also perform other generic CSF tweaks after that.
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