======================= OSPF Dead Timer Reset ======================= Overview -------- RFC 4222 Recommendation 2 advises that when packet prioritization is not feasible, an OSPF implementation should refresh the neighbor inactivity (dead) timer upon receipt of *any* valid OSPF unicast packet, or any OSPF packet sent to AllSPFRouters on a point-to-point link. This prevents unnecessary adjacency loss when Hello packets are delayed or dropped due to congestion. Behavior -------- When ``ip ospf dead-timer-reset any-control`` is enabled, OSPF resets the neighbor inactivity timer upon receipt of: - Any valid unicast OSPF control packet This extends adjacency lifetime even when Hello packets are delayed by low-speed links or control-plane congestion. The default behavior is to reset the dead timer only upon receipt of Hello packets. Implementation Notes -------------------- - The logic is implemented in the neighbor receive path. - Only packets that pass basic validation reset the timer. - The feature is enabled per-interface under the OSPF daemon. - The ``no`` form restores the default Hello-only behavior. - Note RFC 4222 Cautions this may interact with RFC 4222 recommendation 1 see the RFC for details. References ---------- - RFC 4222