February 14, 2023


Posted on February 14, 2023  •  1 minutes  • 179 words  •  Suggest Changes

Mastering firewall management is essential for maintaining the security and integrity of computer systems. In the realm of Linux, firewalld has emerged as a powerful and flexible firewall solution, providing administrators with fine-grained control over network traffic. Understanding the basics of firewalld and its command-line interface is crucial for effectively configuring and managing firewall rules.

Before we dive into the specific commands, it is worth noting that firewalld comes pre-installed on many modern Linux distributions, including Fedora, CentOS, and Red Hat Enterprise Linux. However, it is always a good practice to verify its presence on your system and ensure it is up-to-date before proceeding.

Get all zones

firewall-cmd --get-zones

query zones (default:public)

firewall-cmd --list-all
firewall-cmd --list-all --zone=public
firewall-cmd --list-all --zone=internal

check the applications

firewall-cmd --zone=public --list-services

add application to zone

# add it
firewall-cmd --zone=external --add-service=ftp

# reload : gone again
firewall-cmd --reload

# add it perm
 firewall-cmd --zone=external --add-service=ftp --permanent

remove application from zone

firewall-cmd --permanent --zone=external --remove-service=ftp

add specific port

firewall-cmd --permanent --zone=external --add-port=60001/udp

create custom zones

firewall-cmd --permanent --new-zone=my_personal_zone
firewall-cmd --permanent --zone=my_personal_zone --add-interface=eth0
firewall-cmd --remove-interface=enp0s8 --zone=my_personal_zone

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