Path monitoring checks the network connectivity and link state for an IP address or group of IP addresses (path group). The active peer uses ICMP pings to verify that one or more destination IP addresses can be reached. For example, you can monitor the availability of interconnected networking devices like a router or a switch, connectivity to a server, or some other vital device that is in the flow of traffic. Make sure that the node/device configured for monitoring is not likely to be unresponsive, especially when it comes under load, as this could cause a path monitoring failure and trigger a failover.

The default ping interval is 5,000ms. An IP address is considered unreachable when three consecutive pings (the default value) fail, and a peer failure is triggered when any or all of the IP addresses monitored become unreachable. By default, if any one of the IP addresses becomes unreachable, the HA state transitions to non-functional.