OSPF: A Network Routing Protocol

OSPF: A Network Routing Protocol

Released December 2015
Publisher(s): Apress
ISBN: 9781484214107

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Book description

Learn how routers network using the OSPF (Open Shortest Path First) protocol and unpick Dijkstra’s Network Algorithm to see how OSPF performs the calculations to determine the shortest or most appropriate path between two routers. OSPF: A Network Routing Protocol dives deep into the OSPF protocol without sacrificing simplicity in language. All of this is done with running examples and illustrations to clarify concepts and enhance the enjoyment of networking.

OSPF: A Network Routing Protocol is an absorbing, comprehensible account of OSPF, including the algorithm which is used for calculating its routes. While OSPF has traditionally been an organizational networking protocol, in these exciting times of Software Defined Networking (SDN), it has assumed an important role in the consolidated data center too. Now that the traditional distinctions between server and network roles are getting blurred, everyone in the data center needs to become familiar with networking and networking protocols.

Table of contents

  1. Cover
  2. Title
  3. Copyright
  4. Dedication
  5. Contents at a Glance
  6. Contents
  7. About the Author
  8. About the Technical Reviewer
  9. Acknowledgments
  10. Introduction
  11. Chapter 1 : Six Degrees of Separation
    1. Origins
    2. Reflections
    3. References
  12. Chapter 2 : A LinkedIn User’s Professional Circles
    1. Creating a Personal Network
    2. Tabulating a Personal Network
  13. Chapter 3 : Router Physiology 101
    1. The Cloud
    2. Imagine That You Are a Router
    3. Signals and Characters
    4. Vocabulary and Syntax
  14. Chapter 4 : The OSI Model—Division of Labor
    1. The OSI Reference Standard
    2. Layering
  15. Chapter 5 : The OSI Model—A Closer Look
    1. The Physical Layer (L1)
    2. The Data Link Layer (L2)
    3. The Network Layer (L3)
    4. The Transport Layer (L4)
    5. The Session Layer (L5)
    6. The Presentation Layer (L6)
    7. The Application Layer (L7)
  16. Chapter 6 : Network Addresses
    1. The IP Address
    2. The Network Prefix Length
    3. When Addresses are Prefixed or Masked
    4. Variable-Length Subnet Masking
  17. Chapter 7 : The Magnificent Internet Protocol
    1. The Structure of an IP Datagram
    2. The Fields of an IP Datagram
      1. Version
      2. Header Length
      3. Differentiated Services
      4. Total Length
      5. Fragmentation and Reassembly
      6. Identification
      7. Fragment Offset
      8. Flags
      9. Time to Live Field
      10. Protocol
      11. Header Checksum
      12. IP Options and Padding
  18. Chapter 8 : A Router’s Got to Learn Its Routing Table …
    1. Some Reflections on Maps and Directions
    2. Networks as Graphs
    3. The Attributes of a Route
    4. The Routing Protocol
  19. Chapter 9 : “Hello” Greetings from a Router
    1. Hello Message
    2. The Neighbor Database
    3. Some Caveats
  20. Chapter 10 : Hello Again, Neighbor!
    1. The OSPF Protocol Header
    2. The Structure of the “Hello” Message
    3. The Operation of the Hello Protocol
    4. Router Database Synchronization using Designated Routers
    5. Broadcast Networks
      1. Discovery or Election of DR and BDR
      2. Multicasting for Transmission of OSPF Packets
  21. Chapter 11 : The Master Table
    1. There’s One Master Table
      1. The Master Database
      2. A Subscriber’s Personal Routing (Networking) Table
    2. Every Subscriber Presents a Unique View
  22. Chapter 12 : An Organizational Network
    1. An Organization-Wide Network
      1. The Router IP Addresses
      2. The Network Numbers
      3. Network Devices
      4. Network Interactions
    2. The Operationalized Organizational Network
  23. Chapter 13 : The Secret of Routing Powers
    1. A Sharing of Information
    2. The Similarities to LinkedIn Networking
    3. The Differences from LinkedIn Networking
    4. Separate Yet Identical Databases
  24. Chapter 14 : The Enterprise Network—Recognizing the Neighbors
    1. Link State Advertisements and Databases
    2. The LSA Calling Card
    3. Database Synchronization
    4. LSA Exchanges vs. “Hello” Messages
    5. Bidirectional Communications
    6. Failure and Recovery
  25. Chapter 15 : Splitting the Autonomous System into Areas
    1. The Autonomous System Split into Areas
    2. Arrangement of the Areas
      1. The Backbone, or Hub
      2. The Paths and Area Routers
      3. Inter-Area Routing
    3. Repair of Partitioned Areas
    4. Domain Overview and Trust
  26. Chapter 16 : Link State Advertisements
    1. The Role of Link State Advertisements
    2. The LSA Header
      1. LS Age
      2. Options
      3. LS Type
      4. Link State ID
      5. Advertising Router
      6. LS Sequence Number
      7. LS Checksum
      8. Length
      9. Comparing Two Instances of an LSA
    3. Router LSAs
      1. Link ID
      2. VEB
      3. Number of Links
      4. Link Description
      5. Type Field
      6. Router LSA Overview
    4. Network LSAs
      1. Network Mask
      2. Attached Router
    5. Summary LSAs
      1. Network Mask
      2. Metric Field
      3. TOS Options Field
    6. AS-External LSAs
      1. Network Mask
      2. Bit-E Field
      3. Metric Field
      4. Forwarding Address Field
      5. External Route Tag Field
      6. Supporting Stub Areas
    7. Chapter Summary
  27. Chapter 17 : The Enterprise Network–Neighborhood Activity
    1. Synchronization
    2. Flooding
    3. The Packets
  28. Chapter 18 : OSPF Messages
    1. The Types of Messages Sent
    2. The Database Description Packet
      1. Fields in the Description Packet
      2. Roles of Slave and Master
    3. Link State Request Packet
    4. The Link State Update Packet
    5. The Link State Acknowledgment Packet
    6. The Designated Router and Its Backup
  29. Chapter 19 : An Enterprise Network — Convergence of Data
    1. The Synchronization of Routers
    2. Airline Flight Routes
    3. Flight Costs and Other Factors
  30. Chapter 20 : Dijkstra’s Algorithm — The First Look
    1. Puzzles and Algorithms
      1. Selecting Specific Members
      2. Arranging Members in Order of Height
    2. The Shortest Airplane Route
      1. Some Considerations
  31. Chapter 21 : Dijkstra’s Algorithm – The Closest Look
    1. The Puzzle of Finding the Cheapest Flight
    2. Considering the Indirect Route
    3. The Algorithmic Approach
      1. The Procedure
  32. Chapter 22 : Bibliography
    1. Published References
    2. Internet References
  33. Index

Product information

  • Title: OSPF: A Network Routing Protocol
  • Author(s):
  • Release date: December 2015
  • Publisher(s): Apress
  • ISBN: 9781484214107