9.1. Introduction to Link-State Routing9.1.1. Theoretical Basis9.1.2. Dijkstra Algorithm9.1.3. Database Synchronization and Flooding Algorithm9.1.4. Calculating Routing Information9.1.5. Overview of Link-State Routing Protocols9.2. Open Shortest Path First (OSPF)9.2.1. Basic Characteristics9.2.1.1. Subprotocols9.2.1.2. Structure of OSPF Routing Domain9.2.1.3. Types of Routing within an OSPF Domain9.2.1.4. Route Aggregation9.2.1.5. Convergence Characteristics9.2.2. General Data Structures9.2.3. Intra-Area Routing9.2.3.1. Overview of Intra-Area OSPF Functionality9.2.3.2. Types of Networks and Topology AbstractionPoint-to-Point NetworksBroadcast NetworksNBMA NetworksPoint-to-Multipoint NetworksVirtual LinksInterfaces in Loopback State9.2.3.3. OSPF Transport Protocol and Packet Formats9.2.3.4. Options Field9.2.3.5. Hello Subprotocol9.2.3.6. Interface State Machine9.2.3.7. Designated Router Election Algorithm9.2.3.8. Adjacencies and Neighbor State Machine9.2.3.9. OSPF Topology Abstraction and Types of LSAs9.2.3.10. Origination of LSAs9.2.3.11. Flooding and LSDB Maintenance ProceduresSources of New InformationReceiving the LSAsLSA Installation and SPF SchedulingFlooding the LSA to Other NeighborsSpecial Cases in Flooding AlgorithmLSA Aging, Periodic Checking, and Removal9.2.3.12. Routing Table Calculation9.2.3.13. Frequently Asked Questions9.2.4. Inter-Area Routing9.2.4.1. Introduction to Inter-Area Routing and ABR Functionality9.2.4.2. Distribution of Routing Information and Types of LSAs9.2.4.3. Inter-area Route Calculation9.2.4.4. Origination of Summary-LSAs9.2.4.5. Virtual Links9.2.4.6. Cisco ABR Behavior9.2.4.7. Frequently Asked Questions9.2.5. Routing to External Networks in OSPF9.2.5.1. Introduction and Terminology9.2.5.2. Distribution of Routing Information and Types of LSA9.2.5.3. Outline of ASBR Functionality9.2.5.4. External Route Calculation9.2.5.5. Stub and Totally Stub Areas9.2.5.6. Not-So-Stubby Areas9.2.5.7. Frequently Asked Questions9.2.6. Summary of Routing Table Calculation and Route Preference Rules9.2.7. Demand Circuit OSPF Extensions9.2.8. Details of Cisco OSPF Implementation9.2.8.1. Packet Pacing9.2.8.2. LSA Group Pacing9.2.8.3. SPF Scheduling9.2.8.4. Partial SPF Calculation9.2.9. OSPF Configuration9.2.9.1. Basic OSPF Configuration9.2.9.2. General OSPF Parameters9.2.9.3. Interface-Specific Parameters9.2.9.4. Configuring OSPF on NBMA Media9.2.9.5. Basic OSPF ABR Configuration9.2.9.6. Configuring Route Aggregation9.2.9.7. Configuring Virtual Links9.2.9.8. Basic OSPF ASBR Configuration (Route Redistribution)9.2.9.9. Aggregation of Redistributed Routes9.2.9.10. Configuring Stub Areas9.2.9.11. Configuring NSSA9.2.9.12. Tuning OSPF Timers9.2.10. Configuration Examples9.2.10.1. Single-Area OSPF Configuration9.2.10.2. Sample Configurations for OSPF over Frame Relay Cloud9.2.10.3. Configuration of OSPF with Multiple Areas9.2.10.4. Route Redistribution and Stub Areas9.2.10.5. NSSA9.2.11. Summary9.3. References