OSPF LSAs and LSDB flooding Tutorial

Lessons Discussion
58

Hello Navraj

If an OSPF router has an LSA, and since then 30 minutes have elapsed without any newer LSAs being exchanged, then this router will resend its current LSA with an incremented sequence number. This new incremented LSA will be sent to all OSPF neighbors. Specifically, if we use the flow chart in the lesson, it will go like this:

  1. 30 minutes elapsed, new LSA
  2. Entry in LSDB? Yes
  3. Sequence Number different? Yes
  4. Sequence Number higher? Yes
  5. Send LSU with newer information to source

Note here that the information is the same, but it is considered newer because the sequence number is newer.

I hope this has been helpful!

Laz