Research On Firewall Based On The Protected Host

Firewall is a separator located between the Internet and LAN such that all packets between them pass through it.Based on the predefined security policy, The firewall inspects each packet to see whether it is safe.It allows only safe packets to pass and denies all others.In this dissertation,the author first introduces the state of the art of the current firewall technology,and analyzes its limitations and drawbacks unsuited to the changing network environment in detail.Then,aimming at the above discussion , puts forward a new firewall architecture based on the protected host,and gives its detailed implementing policy. Finally,gives the programming methods of firewall implementation based on the analysis of two different OSs,respectively.