Research,Development And Realization Of The Packet Filter Network Firewall Based On Linux Kernel

Over the last few decades Internet has increased so widely and reached many corners of our homes. Everyday more and more devices are getting connected to Internet. With this widespread use of networks and rapid growth of information between the network transmissions, network security became a major concern of all. Because of increased illegal cyber-attacks of various means, many Internet users feel themselves so vulnerable. Such challenges motivate me to conduct a research and build Network Firewall system. Firewall is a security mechanism that allows limited access to a computer or a network from unauthorized network, allowing only approved traffic in and out according to a predefined thought-out plan. This includes selecting the services appropriate to business needs and barring others that may have significant security holes. While home users protect themselves using end point firewalls that are installed on their computers, business users like companies are obliged to use network firewalls that not only control incoming network traffic but also manage internal traffic. Although the hackers so rampant, but the network security issues are still not able to attach adequate importance, many users consider that the network security issues far from their own. Most of hacking attacks occur mainly due to not correct installation of the firewall. Firewall technology can be divided into four basic types:packet-filtering, network address translation, agent-based and monitoring. My system is the type of packet filtering firewall. Packet filtering technology has the advantage of simple, low cost, relatively simple applications and to a certain extent guarantee the security of the system. This research presents analysis of open source solutions for routing and filtering regular network traffic.In this Thesis work I have done an extensive research on Network Firewall System and finally developed and implemented a Network Firewall System named DMU Network Firewall System based on CentOS Linux Kernel. One mechanism to provide enhanced security for a network is to filter out potentially malicious network packets. Firewalls are designed to provide "policy-based" network filtering. The firewall treats packets leaving, entering, or passing through computer. Basically there is a separate Chain for each of these. Any packet entering the computer goes through the INPUT chain. Any packet that the computer sends out to the network goes through the OUTPUT chain. Any packet that the computer picks up on one network and sends to another goes through the FORWARD chain. The main goal of this project is to develop open source firewall based on Linux. Also I used few applications like PHP, MySQL Database to build up web based graphical interface for user friendly easy administration. This Firewall is functional in a real environment and can be accessed through a user friendly popular Browsers like Internet Explorer or Firefox to manage the Firewall rules.