Chapter 19. High Availability Networking

The following topics are covered in this chapter:

• Measuring Network Availability

• Internetwork Reliability Options

The term high availability can be nebulous to define because the term itself is considered subjective; what one person or network provider considers to be "high availability" does not necessarily mean the same for another person or network service provider.

High availability is a subjective interpretation of two network availability statistics:

• Mean-Time-to-Repair (MTTR) Average time required to recover/restore from a network outage or repair a failed component.

• Mean-Time-Between Failure (MTBF) Average time a network or component works without failure.

This chapter discusses measuring network availability and reliability in addition to the building of redundant networks.