Iptables

External

• http://www.netfilter.org/
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Security_Guide/sec-Using_Firewalls.html#sec-Using_iptables
• http://wiki.centos.org/HowTos/Network/IPTables
• http://www.centos.org/docs/5/html/Deployment_Guide-en-US/ch-iptables.html
• https://help.ubuntu.com/community/IptablesHowTo
• http://www.thegeekstuff.com/2011/01/iptables-fundamentals/
• http://www.frozentux.net/iptables-tutorial/iptables-tutorial.html
• http://www.cyberciti.biz/faq/rhel-fedorta-linux-iptables-firewall-configuration-tutorial/
• http://www.cyberciti.biz/tips/linux-iptables-examples.html

Internal

• Linux 7 Security

Overview

iptables is a Linux command line tool used to query and manipulate the network packet filtering rules maintained by the Linux kernel. Network packet filtering in the kernel is implemented by the netfilter framework. The term "iptables" is also used to refer to the iptables service, which is a systemd service that uses the iptables tool to configure the packet filtering rules at boot. netfilter and iptables are used to implement network firewalls and NAT. The relationships between these concepts is explained in iptables Concepts: netfilter, iptables tool, iptables service and firewalld.

Concepts

iptables Concepts

iptables Service

Getting Information about iptables Service

systemctl status iptables

iptables Service Installation

iptables service and firewalld are incompatible. If iptables service is used, firewalld must be disabled: firewalld#Disable.

yum install iptables
yum install iptables-services

iptables Service Operations

Enable to Start at Boot

After rule configuration, enable the iptables service to start at boot:

systemctl enable iptables