一种基于防火墙的蠕虫传播与控制模型

防火墙对网络蠕虫传播影响的研究，主要集中在单一子网或小规模企业网范围内，针对多子网网络环境下防火墙对网络蠕虫传播的控制作用，提出了基于防火墙的蠕虫传播与控制模型．通过分析网络蠕虫在各子网内传播以及子网间交互传播，利用防火墙减小各子网间蠕虫的交互感染率，使网络蠕虫的传播得到抑制．利用该模型仿真了均匀扫描蠕虫和本地扫描蠕虫在防火墙网络中的传播．结果表明，防火墙对均匀扫描蠕虫的控制效果比较好；对于本地扫描蠕虫，当本地扫描概率较大时，防火墙的作用相对比较差，与实际情况相符．

A model of the worm propagation and control based on firewall

The study of the firewall to the network worm propagation concentrates mainly in the single subnet or the small scale enterprise network. In view of the control of the firewall to network worms under many subnets, a model of the worm propagation and control based on firewall is proposed. By analyzing network worm propagation in a single subnet and cross propagation between subnets, this model reduces the cross infection rate between subnets and suppresses network worm propagation through the firewall. Uniform scanning and local scanning worm propagation are simulated by this model. Results show that the effect of the firewall on uniform scanning worm is good; when the local scan rate is relatively high, the effect of the firewall on local scannin~ worm is relatively poor. which is consistent with the real situation.