Cover image for Packet Guide to Routing and Switching

Book description

This book will cover structure, behavior and fields, all of which will be supported by packet captures and analysis. This second installment will cover layers 2 and 3 and is concerned with the key protocols and operations. It is meant to be a follow up to the first book in the sense that these are more advanced ideas that assume and/or build on the previous ideas. For example, it is difficult to understand routing without first understanding IP. This book will be written to a depth that will serve experts and those first learning about these topics.

Table of Contents

  1. Dedication
  2. Special Upgrade Offer
  3. Preface
    1. Audience
    2. Contents of This Book
    3. Conventions Used in This Book
    4. Using Code Examples
    5. Safari® Books Online
    6. How to Contact Us
    7. Content Updates
      1. September 28, 2012
    8. Acknowledgments
  4. 1. Routing and Switching Strategies
    1. Switching: Forwarding and Filtering Traffic
      1. Forwarding Based on MAC Addresses
    2. Routing: Finding Paths
      1. Routing Devices
      2. Static Routes
      3. Digging a Little Deeper—Common Mistakes
      4. Default Routes
      5. Dynamic Routes
      6. Routing Protocols
        1. Single versus multipath
        2. Interior versus exterior
        3. Flat versus hierarchical
        4. Link state versus distance vector
      7. Choosing or Installing a Route
        1. Prefix length
        2. Administrative distance
        3. Metric
      8. Routing Loops
      9. Discard or Null Routing
    3. IPv6
    4. Reading
    5. Summary
    6. Review Questions
    7. Review Answers
    8. Lab Activities
      1. Activity 1—Interconnected Switches and SATs
      2. Activity 2—Static Routing Topology
      3. Activity 3—Convert to Default Routes
      4. Activity 4—Routing Loop
      5. Activity 5—Null Route
  5. 2. Host Routing
    1. The Decision Process
      1. Case 1: Destination Is on the Same Network as the Source
      2. Case 2: Destination Is on a Different Network than the Source
      3. What If the Default Gateway Is Not Known?
    2. Host Routing Tables
    3. Addressing
    4. Tracking the Packets
      1. Case 1: Destination Is on the Same Network as the Source
      2. Case 2: Destination Is on a Different Network than the Source
    5. Reading
    6. Summary
    7. Review Questions
    8. Review Answers
    9. Lab Activities
      1. Activity 1—Build the Topology Depicted in Figure 2-2
      2. Activity 2—Host Routing Table
      3. Activity 3—ARP Tables
      4. Activity 4—Following the Traffic
      5. Activity 5—Addressing
  6. 3. Spanning Tree and Rapid Spanning Tree
    1. Why Are Loops Bad?
    2. The Structure of Spanning Tree BPDUs
      1. The Comparison Algorithm
      2. Some Definitions
      3. Spanning Tree Addressing
      4. Port States
      5. Spanning Tree Timers
        1. Hello
        2. Max age
        3. Forward delay
    3. The Operation of Spanning Tree
      1. Step 1—Switch 1 Is Powered Up
      2. Step 2—Switch 2 Is Powered Up
      3. Step 3—Switch 3 Is Powered Up
      4. Step 4—Creation of a Loop
    4. Spanning Tree Messages
      1. Problems with Spanning Tree
      2. Switch to Switch: A Special Case
    5. Cisco Improvements
      1. Portfast
      2. Uplinkfast
      3. Backbonefast
    6. VLANs and Spanning Tree
    7. The Rapid Spanning Tree Protocol
      1. The Operation of RSTP
        1. Alternate and backup blocked ports
    8. Security
    9. Reading
    10. Summary
    11. Review Questions
    12. Review Answers
    13. Lab Activities
      1. Activity 1—Capture of a BPDU
      2. Activity 2—BPDU Address Analysis
      3. Activity 3—Looping the Switch Back to Itself
      4. Activity 4—Looping Switches Together
      5. Activity 5—Removing the Loop
  7. 4. VLANs and Trunking
    1. Problem: Big Broadcast Domains
    2. What Is a VLAN?
      1. The Effect of VLANs
      2. VLAN Ports Do Not Need to be Continuous
      3. Types of VLANs
        1. Case 1—DHCP
        2. Case 2—No DHCP
        3. Solution: Dynamic VLANs
      4. VLANs Between Switches
    3. What is a Trunk?
      1. Trunking Protocol Standards
        1. IEEE 802.1Q
        2. Inter-switch link (ISL)
      2. Pruning
    4. VLAN Design Considerations
      1. Security Considerations
    5. Reading
    6. Summary
    7. Review Questions
    8. Review Answers
    9. Lab Activities
      1. Activity 1—Setting Up a Local VLANs
      2. Activity 2—VLANs and the SAT
      3. Activity 3—What Can You See?
      4. Activity 4—Basic Trunking
  8. 5. Routing Information Protocol
    1. Version 1 Versus Version 2
    2. Protocol Description
    3. Structure
    4. Basic Operation
      1. Timers
      2. Addressing
    5. Advanced Operation
      1. Split Horizon
      2. Poisoning
      3. Poison Reverse
      4. Triggered Updates
      5. Count to Infinity
    6. How Do I Get Off of My Network?
    7. RIP and Loops
    8. Security
    9. RIP and IPv6
    10. Reading
    11. Summary
    12. Review Questions
    13. Review Answers
    14. Lab Activities
      1. Activity 1—Build the Topology Depicted in Figure 5-28
      2. Activity 2—Enable RIP on the Routers
      3. Activity 3—Split Horizon
      4. Activity 4—Loss of a Route
      5. Activity 5—Timers
  9. 6. Open Shortest Path First
    1. Protocol Description
    2. Being Link State
    3. Structure and Basic Operation
      1. Hello
      2. DB Description
        1. Link state advertisement (LSA) header
      3. Link State Request
      4. Link State Update
      5. Link State ACK
      6. Timers
    4. Advanced Operation
    5. OSPF and IPv6
    6. Reading
    7. Summary
    8. Review Questions
    9. Review Answers
    10. Lab Activities
      1. Activity 1—Build the Topology Depicted in Figure 6-23
      2. Activity 2—Enable OSPF on the Routers
      3. Activity 3—Tracing the Packet Flow
      4. Activity 4—Changing Network Conditions
      5. Activity 5—A Loop
  10. About the Author
  11. Colophon
  12. Special Upgrade Offer
  13. Copyright