This chapter discusses the Open Shortest Path First (OSPF) protocol for distributing routing information between routers belonging to an autonomous system. This chapter provides an overview of the protocol's features and example configuration commands.

This chapter assumes that you are already familiar with IP unicast routing. If not, refer to the following publications for additional information:
  • RFC 2328—OSPF Version 2
  • RFC 1765—OSPF Database Overflow
  • RFC 2370—The OSPF Opaque LSA Option
  • RFC 3101—The OSPF Not-So-Stubby Area (NSSA) Option
  • RFC 3623—Graceful OSPF Restart
  • Interconnections: Bridges and Routers by Radia Perlman. Published by Addison-Wesley Publishing Company (ISBN 0-201-56332-0).


OSPF is available on platforms with an Advanced Edge or Core license. For specific information regarding OSPF licensing, see the Feature License Requirements document.