Chapter 1
System Management
Course: Comptia Linux Xk0 006
Subject: Comptia Linux Xk0 006
Chapter: Security
Linux firewalls control the flow of network traffic based on rules defined by the administrator. They are critical for hardening systems against unauthorized access, lateral movement, and external threats.
1. Firewall Use Cases
Linux firewalls are used to enforce network traffic control, which is critical for security, compliance, and performance. Use cases range from exposing essential services to blocking unwanted access, as well as enabling routing functions like IP forwarding. Proper firewall configuration ensures only authorized services are reachable, reducing the system’s attack surface.
1. Open and Close Ports
Firewalls help control access to services by opening ports for trusted traffic and closing or blocking unused or insecure services. This is especially important in public-facing systems like web servers, application hosts, and VPN gateways.