ResearchandDesignofNIDSBasedonLinuxFirewall1212ZongpuJiaShufenLiu1GuoweiWang'SchoolofComputerScienceandTechnology,JilinUniversity,Changchun,China,13001232SchoolofComputerScienceandTechnology,HenanPolytechnicUniversity,Jiaozuo,China,454003E-mail:jiazp@hpu.edu.cnAbstractFirewallhasma