Hi, On Tue, Jul 28, 2009 at 1:43 PM, Taqdir Singh<[email protected]> wrote: > > Could anyone please explain in **detail** how OSPF is loop free. I have read > somewhere OSPF even doesn't use Split horizon but its alogorithm makes its > loop free.
If you /really/ want the details, you'll need to dig right into Dijkstra's SPF algorithm and in terms of the implementation of the algorithm in OSPF (generically and in IOS), the book "Routing TCP/IP volume 1" (Jeff Doyle) covers it well. Aside from that, the OSPFv2 RFC [1] may help illuminate things for you.[2] At 10,000 feet though, OSPF is loop free because every router in the area runs the same algorithm across the same set of data, coming to the same conclusion about the best way to reach a particular destination. It's high improbable that permanent routing loops will form, unless something else is going haywire in the network or a device has been misconfigured (OSPF doesn't protect you against yourself :-)) cheers, Dale [1] http://www.ietf.org/rfc/rfc2328.txt [2] I've never bothered to read it. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
