If a link flaps on a network with many OSPF neighbor relationships and routes, a large number of DD and Update packets need to be exchanged during OSPF neighbor relationship establishment. After a neighbor relationship reaches the full state on a device, the device floods Update packets along each link, and adds the Update packets to the retransmission list. This process consumes a lot of CPU and memory resources. As a result, other neighbor relationships are interrupted because no Hello packet is received for a long period of time. These neighbor relationships are always being established, and cannot reach the full state.


To address this problem: Aggregate LSAs to reduce the number of LSAs in LSDBs on devices in non-backbone areas or replace OSPF with IS-IS.

good

very informative

good info

useful document, thanks