Which solution suppress the effect of excessive interface flapping events on routing protocols?

IP Event Dampening assigns an incrementing penalty each time an interface transitions down, and once the cumulative penalty exceeds the configured suppress threshold, the interface state change is no longer reported to routing protocols such as OSPF or BGP. The penalty decays exponentially using a configurable half-life timer, and reporting resumes only when the penalty drops below the reuse threshold, directly absorbing the impact of repeated flapping on routing stability.

SPF Backoff introduces incremental delays between successive SPF recalculations within link-state routing protocols like OSPF or IS-IS to reduce CPU load during instability, but it does not suppress the initial reporting of interface state changes to the routing process.

Carrier Delay adds a timer that defers reporting a carrier-down event to the routing process, which can absorb very brief transient outages, but it is not designed to track cumulative flapping events or apply exponential decay suppression like IP Event Dampening.

BFD (Bidirectional Forwarding Detection) is a sub-second failure detection protocol that accelerates the speed at which routing protocols learn of a forwarding path failure; it increases the sensitivity to link events rather than suppressing them.