Learn how to configure NextHop reachability probes in
The ION device checks if the next hop configured
on the static route is reachable when you enable the
. To check if the next hop is reachable,
the ION device initiates ICMP probes every second and waits 100
ms for a reply from the next hop. Failure to receive 3 consecutive
ICMP responses causes the device to mark the next hop as unreachable
and the device removes the static route. As a result, the device
forwards traffic to the destination prefix via an alternate path
and does not drop traffic due to an unreachable next hop.
device decides the number of probes dynamically based on the next
hops. If multiple static routes have the same next hop, then the
device configures only one probe. If there are multiple next hops,
the device configures multiple probes.
Enable the NextHop
Reachability probe when configuring a static route.