Ixp425-based Firewall Design And Realization

The Internet has entered a new era, and become a part of our life day by day; however, the security problem it brings has also become increasingly inevitable, which we have to pay attention to. Embedded System as a safety, low-cost, efficient platform has been widely used in various fields, and of course network security is one of them.This paper focuses on the development of firewall using IXP425 network processor, after introducing the IXP425 board we customized board support package for the board using Redboot as bootloader, and Snapgear Linux as Operation System. Then the paper analyzes how netfilter, namely Linux firewall's kernel level component, implements firewall's functions and abstracts important data structure and data stream. Based on knowledge above, this paper studies the firewall which can defend common DoS attack:Analyzing the land attacks,SYN flooding attacks and Smurf attacks and indicating a few weadnesses,the paper gives solutions.