Abstract:

The firewall plays an indispensable role in today's network; the configuration of the firewall rules is directly related to the security of the network environment. As the network scale increases, the firewall configuration becomes more complex, in order to improve the protective performance of firewall, the firewall policy audit needs to be applied. At first, this paper researches on the relationship between the firewall rules in detail, summarizes and analyzes some common exception types of rules, and the strategies of the existing audit plan are reviewed. Secondly, this paper discusses the whole working process of the firewall policy audit system, hierarchically analyzes the overall design of the system architecture. Then the configuration rules audit module of the firewall policy audit system is discussed emphatically. Again, this paper discusses the traditional strategy decision tree audit plan, expounds the realization process of the scheme, analyzes and points out the merit and the deficiency of the scheme. Then we put forward an improved audit plan based on the tree structure strategy, discuss the audit process of the scheme in detail and implement the audit plan. Finally we give the graphical reports and detailed audit results of the system, after which we analyze the two by comparing the improved audit plan to the traditional strategy tree.

Key words: firewall, rules relationship, policy tree, conflict, audit