Basics of Linux FirewallPosted by Avijit on August 18th, 2010 Firewall is a combination of software and hardware. The purpose of firewall is control theincoming and out going network traffic. What is ?network traffic?? Okay, network traffic means, when your computer connected with LAN (Local Area Network) or WAN (Wide Area Network) or even in Internet, you all requests converted into data packets and traveled into network. Using data packets, computers exchange their information. Some malicious programmers will take advantage of it, and they crafted the malicious data packets and send it to your computer for malicious purpose. Firewall has the ability to check every data packets and if there is any malicious code inside the data packet, firewall can bock the packet. Not only that, most advanced firewalls can block DDOS (Distributed Denial Of Service) attacks. That?s why all major web hosting company uses those kind of firewalls. Firewalls are highly configurable. You can enhance your security by customizing the firewall options. It is proved that, Linux is more secure than Windows, and now a day, maximum web hosting company, using Linux for their hosting plans. If you are an owner of a VPS or a dedicated server or a real server owner you must know How-To of Linux firewall.From Linux kernel version 2.2, the developers will add the ?ipchain?. "ipchain? is a software-based firewall system in Linux operating system. Later on, in kernel version 2.4 or later version, developers will add another very powerful firewall system called ? ?iptables?. There are lots of other software can improve the performance and customize the ?iptables? such as ? FireHOL. It is a very user-friendly application, using this web masters or system administrators can easily configure the Linux Firewall. It has no GUI; basically it is a large and very complex BASH script file, which do not directly interact with kernel. Rather than it will interact with console based ?iptables? tools. Additionally, you can use IPCop or ShoreWall. The main reasons for using those tools are nothing but extending security. There is another GUI based firewall management tools available on the sourceforge.net named ? Firewall Builder. The current version of this software is ? 4.0. using this GUI based tool, you can drag and drop objects for creating a firewall rules, create group, meta objects, optimize rules and the most important feature is ? you can re-use the common objects like ? IP networks. It is available for different operating systems like ? Windows, MAC OS X, Ubuntu or Debian and Fedora Core (Redhat) Linux. How ever, Linux is good enough for security perspective, but once you connected with a large network, you need a firewall; because a firewall is the stepping-stone of your security. Nevertheless, choice of your application software is your personal preference. Like it? Share it! More by this author |