| Preface |
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xvii | |
| 1 The Motivations for a New Network Architecture |
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1 | (18) |
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The Application-Network Shuffle |
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1 | (4) |
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The Network Design from the Turn of the Century |
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5 | (8) |
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6 | (3) |
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Building Scalable Bridging Networks |
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9 | (4) |
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The Trouble with the Access-Aggregation-Core Network Design |
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13 | (4) |
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13 | (1) |
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14 | (1) |
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15 | (1) |
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16 | (1) |
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16 | (1) |
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17 | (1) |
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17 | (1) |
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18 | (1) |
| 2 Clos: Network Topology for a New World |
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19 | (20) |
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Introducing the Clos Topology |
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20 | (2) |
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A Deeper Dive into the Clos Topology |
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22 | (7) |
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Use of Homogeneous Equipment |
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22 | (1) |
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Routing as the Fundamental Interconnect Model |
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22 | (2) |
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Oversubscription in a Clos Topology |
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24 | (1) |
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25 | (1) |
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26 | (2) |
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Fine-Grained Failure Domain |
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28 | (1) |
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Scaling the Clos Topology |
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29 | (2) |
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Comparing the Two Three- Tier Models |
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31 | (1) |
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31 | (1) |
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31 | (1) |
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Implications of the Clos Topology |
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32 | (1) |
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Rethinking Failures and Troubleshooting |
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32 | (1) |
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33 | (1) |
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Simplified Inventory Management |
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33 | (1) |
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33 | (1) |
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Some Best Practices for a Clos Network |
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33 | (3) |
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Use of Multiple Links Between Switches |
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33 | (1) |
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Use of Spines as Only a Connector |
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34 | (1) |
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Use of Chassis as a Spine Switch |
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35 | (1) |
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36 | (1) |
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37 | (1) |
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38 | (1) |
| 3 Network Disaggregation |
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39 | (14) |
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What Is Network Disaggregation? |
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39 | (3) |
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Why Is Network Disaggregation Important? |
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42 | (1) |
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42 | (1) |
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43 | (1) |
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Standardization of Features |
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43 | (1) |
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What Made Network Disaggregation Possible Now? |
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43 | (1) |
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Difference in Network Operations with Disaggregation |
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44 | (2) |
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44 | (1) |
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45 | (1) |
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Open Network Installer Environment |
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46 | (2) |
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47 | (1) |
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The Players in Network Disaggregation: Hardware |
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48 | (2) |
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48 | (1) |
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49 | (1) |
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49 | (1) |
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49 | (1) |
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Common Myths About Network Disaggregation |
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50 | (1) |
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Some Best Practices for Engaging with Network Disaggregation |
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51 | (1) |
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52 | (1) |
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52 | (1) |
| 4 Network Operating System Choices |
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53 | (28) |
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Requirements of a Network Device |
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54 | (1) |
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The Rise of Software-Defined Networking and OpenFlow |
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55 | (7) |
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More Details About SDN and OpenFlow |
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56 | (2) |
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The Trouble with OpenFlow |
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58 | (2) |
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60 | (1) |
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The Effect of SDN and OpenFlow on Network Disaggregation |
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61 | (1) |
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62 | (10) |
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Location of Switch Network State |
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64 | (2) |
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Programming the Switching Silicon |
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66 | (4) |
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70 | (1) |
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The Reasons Behind the Different Answers |
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70 | (2) |
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72 | (1) |
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Comparing the NOS Models with Cloud Native NOS Requirements |
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73 | (5) |
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Illustrating the Models with an Example |
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73 | (5) |
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What Else Is Left for a NOS to Do? |
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78 | (1) |
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78 | (1) |
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79 | (2) |
| 5 Routing Protocol Choices |
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81 | (30) |
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82 | (8) |
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How Routing Table Lookups Work |
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83 | (2) |
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85 | (1) |
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Types of Routing Table Entries |
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86 | (1) |
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87 | (3) |
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Routing Protocols Overview |
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90 | (1) |
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Distance Vector Protocols Versus Link-State Protocols |
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91 | (4) |
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Distance Vector Dissected |
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91 | (2) |
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93 | (2) |
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Summarizing Distance Vector Versus Link-State Route Exchange |
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95 | (1) |
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Comparing Distance Vector and Link-State Protocols |
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95 | (7) |
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Scaling in Link-State and Distance Vector Protocols |
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95 | (1) |
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Multipathing in Distance Vector and Link-State Protocols |
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96 | (1) |
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97 | (1) |
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Propagation Delay in Link-State and Distance Vector Protocols |
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97 | (1) |
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98 | (1) |
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98 | (2) |
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Routing Configuration Complexity |
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100 | (2) |
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Routing Protocols in Clos Networks |
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102 | (5) |
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Link-State Versus Distance Vector When Links or Nodes Fail |
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102 | (3) |
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Route Summarization in Clos Networks |
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105 | (1) |
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106 | (1) |
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Bidirectional Forwarding Detection |
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107 | (1) |
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Requirements of a Routing Protocol in the Data Center |
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108 | (1) |
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108 | (1) |
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108 | (1) |
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Rare or Futuristic Requirements |
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109 | (1) |
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Choosing the Routing Protocol for Your Network |
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109 | (1) |
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110 | (1) |
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110 | (1) |
| 6 Network Virtualization |
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111 | (30) |
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What Is Network Virtualization? |
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112 | (1) |
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Uses of Network Virtualization in the Data Center |
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113 | (2) |
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Forcing Traffic to Take a Certain Path |
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113 | (1) |
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Applications That Require L2 Adjacency |
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114 | (1) |
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115 | (1) |
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Separating Switch Management Network from Data Traffic |
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115 | (1) |
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Network Virtualization Models |
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115 | (3) |
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Service Abstraction: L2 or L3 |
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116 | (1) |
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Inline Versus Overlay Virtual Networks |
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117 | (1) |
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Network Tunnels: The Fundamental Overlay Construct |
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118 | (5) |
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Benefits of Network Tunnels |
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120 | (1) |
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The Drawbacks of Network Tunnels |
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121 | (2) |
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Network Virtualization Solutions for the Data Center |
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123 | (2) |
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123 | (1) |
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123 | (1) |
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123 | (2) |
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Other Network Virtualization Solutions |
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125 | (1) |
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Practical Limits on the Number of Virtual Networks |
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125 | (3) |
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Size of Virtual Network ID in Packet Header |
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126 | (1) |
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126 | (1) |
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Scalability of Control Plane and Software |
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126 | (1) |
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127 | (1) |
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Control Protocols for Network Virtualization |
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128 | (2) |
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Relationship of Virtual and Physical Control Plane |
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128 | (1) |
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The Centralized Control Model |
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129 | (1) |
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The Protocol-Based Control Model |
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129 | (1) |
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Vendor Support for Network Virtualization |
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130 | (1) |
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130 | (1) |
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130 | (1) |
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130 | (1) |
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Illustrating VXLAN Bridging and Routing |
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131 | (9) |
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VXLAN Bridging Example: H1 to H5 |
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133 | (3) |
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VXLAN and Routing: H1 to H6 |
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136 | (3) |
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Summarizing VXLAN Bridging and Routing |
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139 | (1) |
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140 | (1) |
| 7 Container Networking |
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141 | (20) |
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Introduction to Containers |
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142 | (1) |
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143 | (3) |
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144 | (2) |
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Virtual Ethernet Interfaces |
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146 | (2) |
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Container Networking: Diving In |
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148 | (10) |
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Single-Host Container Networking |
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148 | (6) |
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Multihost Container Networking |
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154 | (4) |
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Comparing Different Container Network Solutions |
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158 | (1) |
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159 | (1) |
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160 | (1) |
| 8 Multicast Routing |
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161 | (22) |
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Multicast Routing: Overview |
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162 | (2) |
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The Uses of Multicast Routing |
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163 | (1) |
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Problems to Solve in Multicast Routing |
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164 | (4) |
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Building a Multicast Tree |
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164 | (1) |
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Multicast Routing Protocol |
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165 | (3) |
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168 | (12) |
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168 | (1) |
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Building a Multicast Distribution Tree |
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168 | (11) |
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179 | (1) |
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PIM-SM in the Data Center |
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180 | (2) |
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182 | (1) |
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182 | (1) |
| 9 Life on the Edge of the Data Center |
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183 | (12) |
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183 | (1) |
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184 | (6) |
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Why Connect to the External World? |
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184 | (1) |
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Bandwidth Requirements for External Connectivity |
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184 | (1) |
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Connecting the Clos Topology to the External World |
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185 | (2) |
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187 | (1) |
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188 | (2) |
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Hybrid Cloud Connectivity |
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190 | (3) |
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193 | (2) |
| 10 Network Automation |
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195 | (38) |
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What Is Network Automation? |
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196 | (1) |
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Who Needs Network Automation? |
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197 | (1) |
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Does Network Automation Mean Learning Programming? |
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198 | (1) |
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Why Is Network Automation Difficult? |
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199 | (5) |
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The Trouble with IP Addresses and Interfaces |
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201 | (1) |
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201 | (1) |
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Network Protocol Configuration Complexity |
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202 | (1) |
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Lack of Programmatic Access |
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203 | (1) |
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Traditional Network OS Limitations |
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203 | (1) |
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What Can Network Developers Do to Help Network Automation? |
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204 | (1) |
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Tools for Network Automation |
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204 | (3) |
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Automation Best Practices |
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207 | (1) |
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208 | (11) |
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210 | (2) |
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212 | (4) |
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216 | (1) |
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217 | (2) |
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A Typical Automation Journey |
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219 | (9) |
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219 | (2) |
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Automate the Configuration That Was Not Device Specific |
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221 | (1) |
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Template the Routing and Interface Configuration |
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222 | (1) |
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More Templating and Roles |
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223 | (3) |
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Some Observations from Fellow Journeymen |
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226 | (2) |
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Validating the Configuration |
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228 | (4) |
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228 | (1) |
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Commit/Rollback in the Age of Automation |
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228 | (2) |
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Vagrant and Network Testing |
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230 | (1) |
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231 | (1) |
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232 | (1) |
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232 | (1) |
| 11 Network Observability |
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233 | (14) |
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234 | (1) |
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The Current State of Network Observability |
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235 | (3) |
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The Disenchantments of SNMP |
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235 | (2) |
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Box-by-Box Approach to Network Observability |
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237 | (1) |
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Why Is Observability Difficult with Networking? |
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238 | (1) |
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Observability in Data Center Networks: Special Characteristics |
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238 | (2) |
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Decomposing Observability |
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240 | (1) |
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The Mechanics of Telemetry |
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240 | (4) |
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240 | (2) |
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242 | (1) |
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243 | (1) |
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243 | (1) |
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The Uses for Multiple Data Sources |
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244 | (1) |
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245 | (1) |
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246 | (1) |
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246 | (1) |
| 12 Rethinking Network Design |
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247 | (10) |
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Standard, Simple Building Blocks |
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248 | (2) |
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249 | (1) |
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Failure: Missing the Forest for the Trees |
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250 | (2) |
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L2 Failure Model Versus L3 Failure Model |
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250 | (1) |
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Simple Versus Complex Failures |
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251 | (1) |
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251 | (1) |
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252 | (2) |
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How the Right Architecture Helps |
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253 | (1) |
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253 | (1) |
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Constraints on the Cloud Native Network Design Principles |
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254 | (1) |
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255 | (2) |
| 13 Deploying OSPF |
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257 | (30) |
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258 | (1) |
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The Problems to Be Addressed |
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259 | (4) |
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Determining Link-State Flooding Domains |
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260 | (1) |
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Numbered Versus Unnumbered OSPF |
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261 | (1) |
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261 | (1) |
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262 | (1) |
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Requirements for Running OSPF on Servers |
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262 | (1) |
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263 | (3) |
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The Messiness of Stubbiness |
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265 | (1) |
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266 | (2) |
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Dissecting an OSPF Configuration |
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268 | (17) |
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Configuration for Leaf-Spine in a Two- Tier Clos Topology: IPv4 |
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268 | (9) |
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Configuration for Leaf-Spine in a Two- Tier Clos Topology: IPv6 |
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277 | (2) |
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Configuration with Three- Tier Clos Running OSPF |
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279 | (1) |
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Configuration with Servers Running OSPF: IPv4 |
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280 | (4) |
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Summarizing Routes in OSPF |
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284 | (1) |
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284 | (1) |
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285 | (1) |
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286 | (1) |
| 14 BGP in the Data Center |
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287 | (14) |
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288 | (7) |
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288 | (1) |
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289 | (1) |
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290 | (1) |
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290 | (1) |
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291 | (1) |
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BGP Attributes, Communities, Extended Communities |
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291 | (1) |
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BGP Best-Path Computation |
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292 | (1) |
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Support for Multiple Protocols |
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293 | (1) |
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293 | (2) |
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Adapting BGP to the Data Center |
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295 | (5) |
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295 | (1) |
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296 | (1) |
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296 | (1) |
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BGP's ASN Numbering Scheme |
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296 | (2) |
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298 | (1) |
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Fixing BGP's Convergence Time |
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299 | (1) |
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300 | (1) |
| 15 Deploying BGP |
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301 | (34) |
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Core BGP Configuration Concepts |
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301 | (2) |
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Traditional Configuration for a Two- Tier Clos Topology: IPv4 |
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303 | (4) |
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307 | (1) |
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308 | (6) |
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Route Maps: Implementation of Routing Policy |
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310 | (4) |
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Providing Sane Defaults for the Data Center |
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314 | (2) |
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BGP Unnumbered: Eliminating Pesky Interface IP Addresses |
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316 | (9) |
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317 | (1) |
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How Unnumbered Interfaces Work with BGP |
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318 | (6) |
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Final Observations on BGP Configuration in FRR |
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324 | (1) |
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Unnumbered BGP Support in Routing Stacks |
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325 | (1) |
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325 | (1) |
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325 | (1) |
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326 | (2) |
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Peering with BGP Speakers on the Host |
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328 | (3) |
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330 | (1) |
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331 | (2) |
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331 | (1) |
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GRACEFUL_SHU TDOWN Community |
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332 | (1) |
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332 | (1) |
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333 | (1) |
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333 | (2) |
| 16 EVPN in the Data Center |
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335 | (32) |
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336 | (1) |
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The Problems a Network Virtualization Control Plane Must Address |
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336 | (1) |
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Where Does a V TEP Reside? |
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337 | (1) |
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One Protocol to Rule Them All, Or...? |
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338 | (3) |
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338 | (2) |
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Separate Underlay and Overlay Protocols |
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340 | (1) |
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341 | (1) |
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BGP Constructs to Support Virtual Network Routes |
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341 | (5) |
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342 | (1) |
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343 | (1) |
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344 | (1) |
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344 | (1) |
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Communicating Choice of BUM Handling |
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345 | (1) |
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346 | (8) |
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EVPN Bridging with Ingress Replication |
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347 | (2) |
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EVPN Bridging with Routed Multicast Underlay |
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349 | (4) |
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353 | (1) |
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Support for Dual-Attached Hosts |
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354 | (5) |
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Host-Switch Interconnect Model |
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355 | (1) |
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VXLAN Model for Dual-Attached Hosts |
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356 | (1) |
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357 | (1) |
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358 | (1) |
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Avoiding Duplicate Multidestination Frames |
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359 | (1) |
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359 | (2) |
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361 | (3) |
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Centralized Versus Distributed Routing |
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361 | (1) |
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Symmetric Versus Asymmetric Routing |
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362 | (1) |
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363 | (1) |
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363 | (1) |
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Deploying EVPN in Large Networks |
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364 | (1) |
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365 | (2) |
| 17 Deploying Network Virtualization |
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367 | (24) |
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The Configuration Scenarios |
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367 | (2) |
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Device-Local Configuration |
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369 | (3) |
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372 | (8) |
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OSPF Underlay, iBGP Overlay |
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380 | (9) |
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allowas-in Versus Separate ASN |
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385 | (1) |
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386 | (3) |
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389 | (1) |
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389 | (1) |
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390 | (1) |
| 18 Validating Network Configuration |
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391 | (48) |
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Validating the Network State |
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393 | (1) |
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393 | (3) |
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396 | (6) |
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Using Ansible to Validate Cabling |
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399 | (3) |
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Interface Configuration Validation |
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402 | (4) |
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Automating Interface Configuration Validation |
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405 | (1) |
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Routing Configuration Validation |
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406 | (22) |
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Validating an OSPF Configuration |
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407 | (7) |
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Validating a BGP Configuration |
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414 | (9) |
|
Stripping the Private ASNs |
|
|
423 | (5) |
|
Validating Network Virtualization |
|
|
428 | (6) |
|
Application's Network Validation |
|
|
434 | (2) |
|
|
|
436 | (1) |
|
|
|
437 | (2) |
| 19 Coda |
|
439 | (2) |
| Glossary |
|
441 | (6) |
| Index |
|
447 | |
