The proxy firewall maintain context more easily than the packet filter firewall.

　　代理防火墻比包過濾器防火墻易于保持更多的上下文

　　The firewall sit between the power phone system internal network and the public data network.

　　防火墻位于強力電話系統(tǒng)內部網絡與公共數據網絡之間。

　　The packet filter rout provide the same functionality as the packet filter firewall describe in section2.1.1.

　　包過濾路由器與包過濾防火墻具有同一功能，如2。1。1部分所述。

　　Inside of the firewall the only permit destination for traffic from the interior or exterior route is the bastion host.

　　在防火墻內部，對于來自內外部路由器的通信量來說，唯一允許到達的目的地是bastion主機。

1. Distributed Firewall
   Fang: A Firewall Analysis Engine
2. Fang: A Firewall Analysis Engine
   Firmato: a novel firewall management toolkit
3. Implementing a distributed firewall
   FIREMAN: a toolkit for firewall modeling and analysis
4. Firewall system for protecting network elements connected to a public network
   A Quantitative Study of Firewall Configuration Errors
5. Conflict classification and analysis of distributed firewall policies
   Implementation of a content-scanning module for an Internet firewall