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.