This book is a concise and complete OSPF command handbook. It provides many configuration examples. In the case of using only a few routers, it demonstrates the correct usage of each OSPF command. By this, the readers can learn each OSPF command, without a need to build large and expensive lab network environment. The book covers many topics of OSPF configuration, including interface configuration, OSPF zone configuration, route filtering, OSPF process configuration, default route generation, route redistribution, administrative distance, OSPF neighbor relationship, route summarization, and show, debug and clear commands. It is suitable for those preparing for CCNA, CCNP, or CCIE to read. It is also essential reference for the engineers and technicians engaged in computer network design, management and operation maintenance.