Overview

The network is the entry point to your application. It provides the first gatekeepers that control access to the various servers in your environment. Servers are protected with their own operating system gatekeepers, but it is important not to allow them to be deluged with attacks from the network layer. It is equally important to ensure that network 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 the router, the firewall, and the switch. Figure 15.1 shows these core components.

Figure 15.1: Network components: router, firewall, and switch