With the rapid development of the Internet, the threat of network information security is becoming more and more serious. So the variety of information security protection applications are used more and more widely. Whether it is traditional access control equipment FW(Firewall) or a new type of more advanced protection means such as intrusion prevention system (IPS), Unified threat management platform (UTM), Anti-denial service attack system (Anti-DDoS), Anti-span Gateway, Unified DPI Traffic Identification and Control System, and many security devices/tools are deployed in inline series network key nodes, the implementation of the corresponding data security policy to identify and deal with legal / illegal traffic. At the same time, however, the computer network will generate a large network delay, packet loss or even network disruption in the case of fail over, maintenance, upgrade, equipment replacement and so on in a highly reliable production network application environment, users cannot stand it.