There are some situations where you just don’t want any traffic flowing through a particular router unless there are ABSOLUTELY NO other alternatives. How can we do that? Tell a particular router to advertise his/her LSAs with the maximum metric possible (0xFFFF).
If you’re looking for a ridiculously easy way to make your OSPF process more efficient, you’ve come to the right place. According to Cisco, many of the CPU cycles spent on evaluating Dijkstra’s algorithm are unnecessary. You can save your router a lot of work by performing incremental SPF calculations in many cases rather than full SPF calculations.
How do you do it? It’s easy:
R0(config)# router ospf 1
That’s it! Best of all, it doesn’t cause the adjacency to drop and it doesn’t need to be enabled on all routers!
I’ve got two routers, R0 and R1, with an OSPF adjacency between them. R0 doesn’t have much memory and he’s getting concerned that R1 is sending him too many LSAs.
Let’s say you’re in The Lab and are asked to minimize OSPF traffic on a link. What does that mean? How can you do it? A quick question mark of OSPF options under an interface will tell you about flood-reduction: