Managing Firewall with firewalld and iptables

Firewalls are an essential part of securing your system from unauthorized access and malicious attacks. In this tutorial, we will discuss how to manage your firewall using firewalld and iptables on a Linux system.

Introduction to Firewalld and Iptables

Firewalld is a dynamic firewall management tool that provides a way to manage firewall rules in a more user-friendly manner. It is the default firewall solution for many modern Linux distributions, including CentOS, Fedora, and Red Hat Enterprise Linux.

Iptables, on the other hand, is a traditional firewall tool that has been around for a long time and is still widely used. It allows for more granular control over firewall rules but can be more complex to manage compared to firewalld.

Installing Firewalld and Iptables

Before you can start managing your firewall, you need to ensure that firewalld and iptables are installed on your system. You can install firewalld using the following command:

yum install firewalld

For iptables, you can install it using:

yum install iptables

Using Firewalld

Once firewalld is installed, you can start and enable the service using the following commands:

systemctl start firewalld
systemctl enable firewalld

You can then use the firewall-cmd command to manage firewall rules. Here are some common commands:

• firewall-cmd --state: Check the status of the firewall
• firewall-cmd --list-all: List all firewall rules
• firewall-cmd --add-port=80/tcp --permanent: Allow incoming traffic on port 80
• firewall-cmd --reload: Reload the firewall configuration after making changes

Using Iptables

To manage firewall rules using iptables, you can use the iptables command directly. Here are some common commands:

• iptables -L: List all firewall rules
• iptables -A INPUT -p tcp --dport 22 -j ACCEPT: Allow incoming SSH traffic on port 22
• iptables-save > /etc/sysconfig/iptables: Save the current firewall rules to a file

Choosing Between Firewalld and Iptables

When deciding between firewalld and iptables, consider the complexity of your firewall rules and your familiarity with each tool. Firewalld is more user-friendly and suitable for basic firewall configurations, while iptables provides more fine-grained control over firewall rules.

Conclusion

In this tutorial, we have discussed how to manage your firewall using firewalld and iptables on a Linux system. Both tools have their strengths and weaknesses, so choose the one that best suits your needs and preferences. Remember to regularly review and update your firewall rules to ensure the security of your system.