Content

| Summary

OSPF is a scalable, standards based link-state routing protocol. The benefits of OSPF include no hop count limitation, the capability to multicast routing updates, faster convergence rates, and optimal path selection. The basic steps for OSPF operation are as follows:

1. Establish router adjacencies
2. Select a designated router and a backup designated router
3. Discover routes
4. Select appropriate routes to use
5. Maintain routing information

Learned in this module were the following:

- The advantages of multiarea OSPF configurations
- The OSPF components used in a large multiarea OSPF internetwork
- The benefits of multiarea configurations include reduced frequency of SPF calculations, smaller routing tables, and reduced LSU overhead.
- The types of areas including stub, totally stubby, and NSSA
- OSPF router types including ABRs and ASBRs
- Link-state advertisements
- Virtual links