VRRP: Increasing Reliability and Failover with the Virtual Router Redundance Protocol

1.1. Availability and Networking

1.1.1. Aspects of Network Availability

Network availability is the concept related to network service outages: it relates to the network design and engineering techniques used either to avoid such outages or to attenuate their impact when they are unavoidable. Although the term outage creates in our mind an association with failure or breakdown, an intentional stoppage also makes a service unavailable. For that reason, we talk about unscheduled (unplanned) as well as scheduled (planned) outages. Despite their predictability, the scheduled outages must equally be taken into account while describing network availability. They are counted as part of the 0.001 percent when the service contract requests 99.999 percent ...