Page 88 - RHEL8 BOOK

Firewalld installation configuration RHEL 7
 Linux is more secure than other Operating Systems, in the way to provide port level security
FirewallD is the best application.
 In Previous Linux versions we used iptables to provide port level security.
 Newer Linux versions firewalld is introduced with great features and enhancements.
 Actual background of iptables and firewalld works based on ipchains which are kernel inbuilt
module.
 IPtables are absolute.

What is mean by port level security..?
Now a days security plays major role in protecting the servers and its data from theft. A simple way to do
packet filtering using firewalld inbuilt application. Allow / Deny incoming connections by writing
firewall rules. In newer version of Linux such as RHEL 7 / Centos 7 and Fedora Firewall by default
disables the port communication to clients except allowed.

FirewallD is available in GUI and CLI as well, CLI tool is firewall-cmd. Using firewall we can allow
particular port to particular network / IP Address, we can also deny particular port for particular network /
IP address.
Note: Do not use default port numbers to increase the security

Firewalld Installation and Configuration on RHEL 7 port level security
In order to use firewalld as a default we have to disable iptables and ip6tables permanently to disable
permanently do below steps, Stop services, Disable services and mask services. When you add mask to
service if any other administrator tyring to start the services will not start until service need to be unmask.

Step 1: Disable iptables & ip6tables services
[root@server ~]# systemctl disable iptables
[root@server ~]# systemctl disable ip6tables

Step 2: Stop Iptables & ip6tables services
[root@server ~]# systemctl stop ip6tables
[root@server ~]# systemctl stop iptables

S. Pradhan
(MCA, MBA-IT, BCA, CCNA, MCSA 2012, RHCE, ETHICAL HACKING)
Email Id:-spradhan.iiht@gmail.com
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