Content

| 6.1 |  | Implementing Module Redundancy in a Multilayer Switched Network |
| 6.1.1 |  | Introducing redundancy |

High network availability rates relies on two key items. The first principle is to eliminate any single point of failure. The second is to distribute intelligence through the architecture. Availability may be increased by adding redundant components, including redundant network devices and connections to multiple WAN links. With the proper design, no single point of failure will impact the availability of the overall system.

The best practice is a design based on modular and hierarchical building blocks that can be replicated to support growth. The infrastructure must also be able to detect and respond quickly to any possible service, link, device, server, or software failure. Users and applications do not notice failures since optimized resiliency technologies ensure fast convergence upon failure. To achieve optimal, fast convergence, multiple networking technologies need to interoperate and complement each other to ensure fast recovery.