Firewall in CentOS

In this tutorial we want to try Firewall in CentOS but before that we ask: What is a firewall? Firewalls are the first line of defense in network security. They are a network security device that can be hardware or software and control incoming and outgoing traffic.

Firewall is a part of network security that controls and filters traffic. The firewall place between the Internet and the end user and filters the Internet based on the rules previously defined for it and whether it allows access or not.

In Linux, Netfilter use to allow access or deny access to network traffic. Filtering packages and their management is particularly useful and important for management in an organization.
If a package enters the server, we need Netfilter to check it so that we can check it according to the rules and allow access or not.

A firewall is a set of rules, and when a packet tries to pass through it, its contents are checked according to the rules of the firewall. A firewall is a tool for managing firewall rules on any Linux machine and it can also be described as a device that examines network traffic (outgoing/incoming connections) and makes traffic decisions.

Now we try to install it in CentOS:

In during this tutorial, we try to Start, Stop, Enable or Disable

First, we check status by command systemctl

If it was inactive in setting let to start it, after starting it, we can check again status.

there are four options to check firewalld that we can use:

[start/stop/disable/enable]

this command is for checking status:

$systemctl status firewalld.service

firewalld is a dynamic firewall that provides support at the trust level of connections or network interfaces and supports IPv4, IPv6 protocols.

let’s to see video from our YouTube channel

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