tailieunhanh - CCNP Routing Study Guide- P6

CCNP Routing Study Guide- P6:T his book is intended to help you continue on your exciting new path toward obtaining your CCNP and CCIE certification. Before reading this book, it is important to have at least read the Sybex CCNA: Cisco Certified Network Associate Study Guide, Second Edition. You can take the CCNP tests in any order, but you should have passed the CCNA exam before pursuing your CCNP. | OSPF Areas THE CCNP ROUTING TOPICS COVERED IN THIS CHAPTER ARE AS FOLLOWS J Introduction to OSPF terminology J Introduction to OSPF functionality J Discussion of OSPF areas routers and link-state advertisements J Discussion of choosing and maintaining routes in particular in multi-access PPP and non-broadcast multi-access networks J Configuration and verification of OSPF operation 01 SYBEX Inc. Alameda CA his chapter is the introduction to Open Shortest Path First OSPF areas. It will introduce the term OSPF areas and discuss their role in OSPF routing. It is very important that you take the time to learn the terminology used in OSPF. Without this knowledge the remaining sections of the chapter will be difficult to follow. Open Shortest Path First Open Shortest Path First OSPF is an open standards routing protocol. It is important to recognize that Cisco s implementation of OSPF is a standards-based version. This means that Cisco based its version of OSPF on the open standards. While doing so Cisco also has added features to its version of OSPF that may not be found in other implementations of OSPF. This becomes important when interoperability is needed. John Moy heads up the working group of OSPF. Two RFCs define OSPF Version 1 is defined by RFC 1131 and Version 2 is defined by RFC 2328. Version 2 is the only version to make it to an operational status. However many vendors modify OSPF. OSPF is known as a link-state routing protocol link-state routing protocols were discussed in Chapter 2 Routing Principles . The Dijkstra algorithm is used to calculate the shortest path through the network. Within OSPF links become synonymous with interfaces. OSPF is a robust protocol and due to the robustness you must learn many terms in order to understand the operation of OSPF. The next section covers the terminology necessary to enable you to understand the many operations and procedures performed by the OSPF process. Copyright 2001 SYBEX Inc. Alameda CA .