Where SPF Algo runs in OSPF

[kthned]

HI TO ALL

When OSPF adjacency is formed, a router goes through several state changes before it becomes fully adjacent

with its neighbor.The states are Down,

Attempt, Init, 2−Way, Exstart, Exchange, Loading, and Full.

My question is "Where the Dijkstra Algo run in above states so that we get the ROUTING Table from TOPOLOGY Database

Thanks in Advance

Syed Umair Ali

[amit-singh]

Syed,

These are the states for the adjacency formation with the neighbors. Once the Adjacency is formed then the OSPF runs the SPF algo to calculate the Shortest path.

From the topological database generated from LSAs, each router calculates a shortest-path tree, with itself as root. The shortest-path tree, in turn, yields a routing table.

Please go through this good link :

http://www.pulsewan.com/data101/ospf_basics.htm

HTH,

-amit singh

[suresh.krishnamurthy]

Hi Syed,

SPF will be run after the OSPF neighbor has just become FULL.

Other timer information on SPF (start,hold,Max) can be seen at the following link:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_feature_guide09186a0080134ad8.html

Regards

Krishnamurthy Suresh

[kthned]

Thank Amit and specially Suresh for ur helpful reply.