Chapter 2. Designing Scalable Enterprise Networks

Modern enterprise network design focuses on achieving high availability, security, and scalability. The modern enterprise follows a certain design methodology to achieve these objectives. This methodology is the product of years of experience, careful feature development, and detailed protocol optimization. Any technology introduced into an enterprise network must not interfere with these principles and mechanisms.

When a network is virtualized, it must continue to meet the resiliency, security, and scalability levels that modern enterprises demand. To continue to deliver the appropriate connectivity level, a virtualized enterprise must follow the same design principles that have traditionally provided the desired resiliency, security, and scalability in campus-, metropolitan-, and wide-area networks.

This chapter presents the network design principles used to achieve enterprise resiliency and scalability objectives. As previously mentioned, these principles should continue to apply to a virtualized network. Resiliency and scalability support is seamless with some virtualization technologies, but you must be careful with certain other techniques because of their potential impact on the resiliency and scalability characteristics of the network. This chapter presents the basic design principles that serve as the framework for the discussion throughout this book. In many cases, the choice of virtual private networking (VPN) technologies is based on the extent of their impact on resiliency.