Such as inefficient capture filtering and reporting, resources\' waste of analyzing enumeration, inefficient pattern matching algorithm, pattern library does not recognize the new invasion, security technology can not be linked coordination, and so on.

DDoS defence system based on packet filtering;

Implementation of a Linux-based all-state packet filtering accounting system;

A model of firewall packet filtering based on the integrated reputation;

Design and realization of the packet filter in the net intrusion and detection;

Design and implement of packet filter firewall on Linux;

Study on fast packet filter under network processor IXP2400;

The basic principle of packet-filtering is analyzed,and the basic process of implementing packet-filtering functions is also discussed in this paper.

A host firewall is a packet-filtering firewall that filters the network packets come from inside the network based on the information of network application pr.

The key functions of IPv6 firewall system, package filter, connection track, package mangle, are discussed.

The filter mechanism of state information is combined with its reserved mechanism by adding state inspection module to the package filter mechanism.

At last, this paper gives a detailed solution about the linkage systems——an efficient package filter firewall based on connecting analysis and an NIDS based on state transferring analysis.