It’s not always possible to secure everything. Often many segments of a network connection will be out of your control, especially if you connect to the Internet in any manner (and who doesn’t nowadays?). Nonetheless, a number of technologies are available to secure the portions of a network that you do control. This part of the book discusses technologies available to harden your network against attacks.
The tools presented in the following chapters provide security for different aspects of network communication. Firewalls and network address translation protect the entry points to a network. Virtual private networking secures data traveling between networks. Traffic shaping ensures consistent availability of high priority network resources. These tools, when used in combination, can provide great protection of network data.