Related to iptables save

Install Iptables on CentOS 7 Server - Step by Step Process ?

This article covers how to disable FirewallD and install and iptables on CentOS 7 server. The iptables service stores configuration in /etc/sysconfig/iptables and /etc/sysconfig/ip6tables , while firewalld stores it in various XML files in /usr/lib/firewalld/ and /etc/firewalld/ . 

Note that the /etc/sysconfig/iptables file does not exist as firewalld is installed by default on Red Hat Enterprise Linux.

FirewallD is a complete firewall solution that can be controlled with a command-line utility called firewall-cmd. If you are more comfortable with the Iptables command line syntax, then you can disable FirewallD and go back to the classic iptables setup.

To Install and Use Iptables Linux Firewall:

1. Connect to your server via SSH.

2. Execute the following command one by one: 

$ sudo apt-get update 
$ sudo apt-get install iptables

3. Check the status of your current iptables configuration by running:

$ sudo iptables -L -v

Location of iptables rules on CentOS ?

CentOS 7 uses FirewallD by default. If you would like to manage iptables/ip6tables rules directly without using FirewallD, you may use the old good iptables-services service which will load the iptables/ip6tables rules saved in /etc/sysconfig/iptables and /etc/sysconfig/ip6tables when it is started during boot time.

How to use Linux command to delete the PREROUTING rule in iptables ?

This article will guide you on how to list and remove/delete iptables pretrouting chain nat rules on your #Linux based system. The -D or --delete option delete one or more rules from the selected chain. There are two versions of this #command, the rule can be specified as a number in the chain or a rule to match. One of the ways to delete #iptables #rules is by rule specification. To do so, you can run the iptables command with the -D option followed by the rule specification.