This chapter provided information to help you select methods for meeting a customer's goals for network security. Security is a major concern for most customers because of the increase in Internet connectivity and Internet applications, and because more users are accessing enterprise networks from remote sites and wireless devices. Also, at the same time that enterprises have become more dependent on their networks, the number of attacks on networks has increased.
The tasks involved with security design parallel the tasks involved with overall network design. It is important to analyze requirements, develop policies, and consider tradeoffs before selecting actual technologies and products to meet the security needs of the various users of an enterprise network. The network should be considered a modular system that requires security for many components, including Internet connections, remote-access networks, network services, end-user services, and wireless networks. To protect the network, you should develop multilayered strategies, procedures, and implementations that provide security defense in depth.