Improving Web Application Security: Threats and - CGISecurity

15Securing Your NetworkIn This Chapter●●●●OverviewSecuring your networkIdentifying network threats and describing countermeasuresShowing secure router, firewall, and switch configurationsProviding a snapshot of a secure networkThe network is the entry point to your application. It provides the first gatekeepersthat control access to the various servers in your environment. Servers are protectedwith their own operating system gatekeepers, but it is important not to allow them tobe deluged with attacks from the network layer. It is equally important to ensure thatnetwork gatekeepers cannot be replaced or reconfigured by imposters. In a nutshell,network security involves protecting network devices and the data that they forward.The basic components of a network, which act as the front-line gatekeepers, are therouter, the firewall, and the switch. Figure 15.1 shows these core components.