What is Sentinel Firewall?
Sentinel Firewall is a modern, automated server security solution designed to protect Linux servers from brute-force attacks, malicious traffic, and unauthorized access. It acts as an intelligent security layer on top of your system firewall, continuously monitoring activity and automatically blocking suspicious IPs to keep your server safe with minimal manual effort.
It’s ideal for VPS and dedicated servers running hosting panels, web services, mail servers, or any internet-facing workload that needs strong yet lightweight protection.
Key Features of Sentinel Firewall
- Automatic Brute-Force Protection – Detects and blocks repeated failed login attempts for services like SSH, FTP, mail, and control panels.
- Real-Time IP Blocking – Instantly bans malicious IPs using iptables, nftables, or firewalld.
- Service Aware Security – Protects common services such as SSH, cPanel/WHM, DirectAdmin, FTP, SMTP, IMAP, POP3, and web services.
- Whitelist & Blacklist Management – Easily allow trusted IPs or permanently block known bad actors.
- Email Alerts & Logs – Get notified about security events and blocked attacks via email.
- Low Resource Usage – Lightweight and optimized to run smoothly on small VPS servers.
- Automatic Updates – Keeps firewall rules and protection mechanisms up to date.
- CLI & Config Based Control – Simple command-line tools and configuration files for full control.
- Hosting Friendly – Works well alongside popular hosting control panels and server setups.
- Proactive Threat Prevention – Stops attacks before they cause service disruption or compromise.
Why Choose Sentinel Firewall?
- Hands Off Security – Automatically handles attacks without constant monitoring.
- Improves Server Stability – Reduces load caused by bots, brute-force attempts, and abusive traffic.
- Perfect for Internet Facing Servers – Essential for servers running SSH, mail, or hosting services.
- Easy to Deploy & Manage – Quick installation with minimal configuration required.
- Panel Compatible – Designed to work smoothly with cPanel, DirectAdmin, and custom server environments.
- Transparent & Auditable – Clear logs and rules so you always know what’s being blocked and why.
- Scales Effortlessly – Suitable for single VPS servers as well as multi-server environments.
- Cost-Effective Security – Provides strong protection without the overhead of heavy security suites.
System Requirements for Sentinel Firewall
- Operating System – Debian 10/11/12, Ubuntu 20.04/22.04, AlmaLinux 8/9, Rocky Linux 8+
- Firewall Backend – iptables, nftables, or firewalld
- Shell Access – Root or sudo privileges required
- Memory – Minimum 512 MB RAM (1 GB recommended)
- Disk Space – Less than 100 MB
- Network – Publicly accessible server with exposed services (SSH, web, mail, etc.)
Installation on Linux OS (Ubuntu based OS):
You can find installation instructions in the CrownCloud Wiki Guides, and it follows:
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