The Research On Linux_based Network Firewall Technology

As the security problem is becoming more and more important, the firewall system are widely used today. The firewall is regarded as important technology for protecting network's security. But many firewall products are very expensive. How can some organizations protect their Intranet's security with limited financial resources?This paper introduces the concepts and principles of network security, network security menace, then sets forth the basic policy of network security in details. After discussing system structures, types and functions, the paper analyses and compares their functions. Base on the analysis of the advantages and disadvantages of the firewall, the paper puts forward a new IP packet filter firewall running on Linux system. Besides conventional functions, it records and analyses IP packet routes passed through. The firewall casts off data packets which don't meet filtering rules, but through insecurity routes. The system solve IP spoofing to some extends. And using NAT, the work realizes that some computers may access Internet by only IP and solves the problem of IP limited.-in order to control the accessing right of users and resist menace from Intranet, the paper improves on a serial of Linux_based network functions and finishes design of the user's access control system by combining password and IP, thereby achieves access control for users.