Introduction
Sentinel includes all the scripts and tools from ConfigServer Firewall & Security (CSF) while preserving the same file names and directory structure, ensuring full compatibility with existing CSF installations. For upgrading from CSF to Sentinel, see: Upgrade guide
ConfigServer Firewall (csf)​
CSF is an SPI iptables firewall that is straight-forward, easy and flexible to configure and secure with extra checks to ensure smooth operation.
csf can be used on any (supported) generic Linux OS.
The Sentinel installation includes preconfigured configurations and control panel UI's for cPanel, OpenPanel, DirectAdmin and Webmin.
Directory structure:
| Directory | Description |
|---|---|
/etc/csf/ | Configuration files |
/var/lib/csf/ | Temporary data files |
/usr/local/csf/bin/ | Scripts |
/usr/local/csf/lib/ | Perl modules and static data |
/usr/local/csf/tpl/ | Email alert templates |
Login Failure Daemon (lfd)​
To complement the Firewall, we have developed a daemon process that runs all the time and periodically (every X seconds) scans the latest log file entries for login attempts against your server that continually fail within a short period of time. Such attempts are often called "Brute-force attacks" and the daemon process responds very quickly to such patterns and blocks offending IP's quickly. Other similar products run every x minutes via cron and as such often miss break-in attempts until after they've finished, our daemon eliminates such long waits and makes it much more effective at performing its task.
There are an array of extensive checks that lfd can perform to help alert the server administrator of changes to the server, potential problems and possible compromises.
On cPanel servers, lfd is integrated into the WHM > Service Manager, which will restart lfd if it fails for any reason.
Control Panel Interface​
To help with the ease and flexibility of the suite we have developed a front-end to both csf and lfd for cPanel, DirectAdmin, OpenPanel and Webmin. From there you can modify the configuration files and stop, start and restart the applications and check their status. This makes configuring and managing the firewall very simple indeed.
There is, of course, a comprehensive Command Line Interface (CLI) for csf.