Linux Intermediate

What is Firewalld?

A dynamic firewall management tool for Linux that provides a D-Bus interface for managing firewall rules with zones.

Firewalld uses zones to define trust levels for network connections. Common zones include public (default, restrictive), trusted (allow all), and internal (trusted internal network). Rules can be added permanently or for the current session only.

Commands: firewall-cmd --add-port=80/tcp --permanent (open port), firewall-cmd --add-service=http --permanent (allow service), firewall-cmd --reload (apply changes). Firewalld replaces iptables on RHEL/CentOS/Fedora systems.

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