Rediscovering IPSec tunnels

When the IP Manager detects a change in the IsDownOrFlapping attribute of a WAN interface that is associated with a tunnel, it places the host router on the short discovery queue for a short discovery for the following reason:

IPSec and IKE tunnels are dynamic in the sense that they can be rerouted to other WAN interfaces when an interface fails. Therefore, when the IP Manager detects a change in the IsDownOrFlapping attribute, it has no way of knowing whether the relationship between the tunnel and the associated WAN interface, as known to the IP Manager, is still valid.

By updating the dynamic indices of the interfaces on the host router, the IP Manager is able to recreate the tunnel association with the WAN interface.