5.1. Flooding Components

Recall from Chapter 2 that flooding is the mechanism by which the topological information originated by an OSPF or IS-IS router is received by all other routers in an area, so that the routers can add the information to their link state databases. Also recall from Chapter 2 that for a link state protocol to operate correctly, the link state databases of every router in an area must be identical. Therefore, flooding requires not just a transport mechanism but also reliability features. Given these requirements, both OSPF and IS-IS flooding use the following components:

  • A “container” packet or PDU for transporting information from one router to the next

  • Reliability features:

    Aging

    Sequencing

    Checksums

  • A means of acknowledging ...

Get OSPF and IS-IS: Choosing an IGP for Large-Scale Networks now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.