As data centers grow in size and complexity, enterprises are adopting server virtualization technologies such as VMware, VMotion, NIC teaming, and server clustering to achieve increased efficiency of resources and to ensure business resilience. However, these technologies often involve significant expense and challenges to deal with complex multisite interconnections and to maintain the high availability of network resources and applications.
Interconnecting Data Centers Using VPLS presents Virtual Private LAN Service (VPLS) based solutions that provide high-speed, low-latency network and Spanning Tree Protocol (STP) isolation between data centers resulting in significant cost savings and a highly resilient virtualized network. The design guidance, configuration examples, and best practices presented in this book have been validated under the Cisco Validated Design (CVD) System Assurance program to facilitate faster, more reliable and more predictable deployments. The presented solutions include detailed information about issues that relate to large Layer 2 bridging domains and offer guidance for extending VLANs over Layer 3 networks using VPLS technology.
Implementing this breakthrough Data Center Interconnect (DCI) strategy will evolve your network to support current server virtualization techniques and to provide a solid foundation for emerging approaches. The book takes you from the legacy deployment models for DCI, problems associated with extending Layer 2 networks, through VPN technologies, to various MST-, EEM-, and GRE-based deployment models and beyond. Although this book is intended to be read cover-to-cover, it is designed to be flexible and allow you to easily move between chapters to develop the solution most compatible with your requirements.
- Describes a variety of deployment models to effectively transport Layer 2 information, allowing your virtualization solution to operate effectively
- Explains benefits and trade-offs of various solutions for you to choose the solution most compatible with your network requirements to ensure business resilience
- Provides detailed design guidance and configuration examples that follow Cisco best practice recommendations tested within the CVD
This book is part of the Networking Technology Series from Cisco Press®, which offers networking professionals valuable information for constructing efficient networks, understanding new technologies, and building successful careers.
Table of Contents:
Introduction xv Chapter 1 Data Center Layer 2 Interconnect 1
Overview of High-Availability Clusters 2
Public Network Attachment 3
Private Network Attachment 3
Data Center Interconnect: Legacy Deployment Models 4
Problems Associated with Extended Layer 2 Networks 5
Summary 7
Chapter 2 Appraising Virtual Private LAN Service 9
VPN Technology Considerations 9
Layer 3 Virtual Private Networks 10
Layer 2 Virtual Private Networks 10
VPLS Overview 11
Understanding Pseudowires 14
VPLS to Scale STP Domain for Layer 2 Interconnection 15
H-VPLS Considerations 17
EEM 18
MPLS 19
Label Switching Functions 19
MPLS LDP 20
MPLS LDP Targeted Session 20
Limit LDP Label Allocation 21
MPLS LDP-IGP Synchronization 21
MPLS LDP TCP “Pak Priority” 21
MPLS LDP Session Protection 22
Summary 22
Chapter 3 High Availability for Extended Layer 2 Networks 23
MTU Evaluation for Intersite Transport 23
Core Routing 25
Mixed MPLS/IP Core 26
Different IGP for IP Core and MPLS 27
Same IGP for IP Core and MPLS 27
Pure MPLS Core 28
Pure IP Core 30
Convergence Optimization 32
Key Convergence Elements 33
Failure Detection and Tuning 33
IP Event Dampening 34
BFD 35
Link Debounce Timer 37
Carrier-Delay Timer 38
Alternate Route Computation 40
Summary 42
Chapter 4 MPLS Traffic Engineering 43
Understanding MPLS-TE 43
Fast Reroute 44
Load Repartition over the Core 45
Load Repartition over a Parallel-Links Bundle 45
Implementing MPLS-TE for Traffic Repartition over Parallel Links 46
Enable TE 47
Create MPLS-TE Tunnels and Map Each VFI to a Tunnel LSP 48
Explicit-Path Option 48
Adding FRR to Explicit Option 50
Affinity Option 52
Adding FRR to Affinity Option 52
Summary 53
Chapter 5 Data Center Interconnect: Architecture Alternatives 55
Ensuring a Loop-Free Global Topology: Two Primary Solution Models 55
N-PE Using MST for Access to VPLS 56
N-PE Using ICCP Emulation for Access to VPLS 56
Data Center Interconnect Design Alternatives: Summary and Comparison 57
Chapter 6 Case Studies for Data Center Interconnect 61
Case Study 1: Large Government Organization 61
Challenges 61
Solution 62
Case Study 2: Large Outsourcer for Server Migration and Clustering 65
Challenges 65
Solution 65
Summary 68
Chapter 7 Data Center Multilayer Infrastructure Design 69
Network Staging for Design Validation 71
Hardware and Software 72
Convergence Tests 73
Traffic Flow 73
Traffic Rate 73
Traffic Profile 74
Summary 76
Chapter 8 MST-Based Deployment Models 77
MST in N-PE: MST Option 1a 77
Implementing MST in N-PE: MST Option 1a Design 80
Convergence Tests 100
Cluster Server Tests 103
VPLS with N-PE Redundancy Using RPVST with Isolated
MST in N-PE: MST Option 1b 106
EEM Scripting to Complement Isolated MST Solution 109
Implementing RPVST in a Data Center with Isolated MST
in N-PE (MST Option 1b) Design 110
Convergence Tests 130
Cluster Server Tests 134
Summary 138
Chapter 9 EEM-Based Deployment Models 139
N-PE Redundancy Using the Semaphore Protocol: Overview 139
Semaphore Definition 141
Semaphore Theory Application 142
N-PE Redundancy Using Semaphore Protocol: Details 142
VPLS PWs in Normal Mode 142
Primary N-PE Failure 145
Primary N-PE Recovers After the Failure 145
Implementing a Semaphore 146
EEM / Semaphore Scripts 147
Naming Conventions 148
Loopback Definitions 148
Node Definitions 149
VPLS with N-PE Redundancy Using EEM Semaphore:
EEM Option 2 150
Control Plane 151
Data Plane 151
Theory of Operation 151
Normal Mode 151
Failure Conditions 152
Primary N-PE Node Failure 153
Primary N-PE Node Recovers After the Failure 154
N-PE Routers: Hardware and Software 154
Implementing VPLS with N-PE Redundancy Using
EEM Semaphore Design 154
Convergence Tests 168
Cluster Server Tests 172
H-VPLS with N-PE Redundancy Using EEM Semaphore:
EEM Option 3 176
Control Plane 179
Data Plane 179
Theory of Operation 179
Normal Mode 179
Primary N-PE Node or Q-Link Failure 180
Primary N-PE Node or Q-Link Recovers After the Failure 181
N-PE Routers: Hardware and Software 182
Implementing H-VPLS with N-PE Redundancy Using EEM Semaphore
Design 182
Convergence Tests 195
Server Cluster Tests 199
Multidomain H-VPLS with N-PE Redundancy: EEM Option 4a 201
Control Plane 203
Data Plane 203
Theory of Operation 204
Normal Mode 204
Primary N-PE Node or Q-Link Failure 204
Primary N-PE Node or Q-Link Recovery After the Failure 205
N-PE Routers: Hardware and Software 207
Implementing Multidomain H-VPLS with N-PE Redundancy
Using EEM Semaphore Design 207
Convergence Tests 217
Server Cluster Tests 221
Multidomain H-VPLS with Dedicated U-PE: EEM Option 4b 227
Multidomain H-VPLS with Multichassis EtherChannel: EEM Option 5a 227
Solution Positioning 230
Multidomain H-VPLS with MEC and VLAN Load Balancing:
EEM Option 5b 230
Control Plane 233
Data Plane 233
Theory of Operation 233
Normal Mode 233
Primary N-PE Node Failure 234
Primary N-P Node Recovers After the Failure 235
N-PE Routers: Hardware and Software 236
Implementing EEM Option 5b 237
Convergence Tests 252
Server Tests 259
Multidomain H-VPLS with MEC and VLAN Load Balancing:
PWs on Active and Standby VPLS Nodes in Up/Up State:
EEM Option 5c 262
N-PE Routers: Hardware and Software 264
Configuration Summary 265
Convergence Tests 270
Summary 275
Chapter 10 GRE-Based Deployment Model 277
Key Configuration Steps for VPLSoGRE-Based Solutions 279
VPLSoGRE with N-PE Redundancy Using EEM Semaphore 282
Convergence Tests 284
Cluster Server Tests 286
VPLSoGRE: Multidomain with H-VPLS Solution 291
Convergence and Cluster Server Tests 296
Cluster Server Tests 298
Summary 302
Chapter 11 Additional Data Center Interconnect Design Considerations 303
Multicast Deployment in a Layer 2 Environment 303
Multicast at Layer 2 304
Tuning the IGMP Query Interval 304
Spanning Tree, HSRP, and Service Module Design 306
Routing Design 306
QinQ MAC Overlapping 307
Storm Control 310
L2 Control-Plane Packet Storm Toward N-PE 311
L2 Broadcast and Multicast Packet Storm 312
L2 Known Unicast Packet Storm 313
L2 Unknown Unicast Packet Storm 314
QoS Considerations 315
Stateful Switchover Considerations 318
IGP (OSPF) Cost 318
Router ID Selection 319
Summary 319
Chapter 12 VPLS PE Redundancy Using Inter-Chassis
Communication Protocol 321
Introducing ICCP 322
Interaction with AC Redundancy Mechanisms 324
Interaction with PW Redundancy Mechanisms 325
Configuring VPLS PE Redundancy Using ICCP 326
Summary 327
Chapter 13 Evolution of Data Center Interconnect 329
A Larger Problem to Solve 329
Networking Technology: Research Directions 330
Improving Legacy L2 Bridging 330
New Concepts in L2 Bridging 331
L2 Service over L3 Transport: MPLS or IP? Battle or Coexistence? 332
Summary 333
Glossary 335
Index 339
About the Author :
Nash Darukhanawalla, CCIE No. 10332, has more than 25 years of internetworking experience. He has held a wide variety of consulting, technical, product development, customer support, and management positions. Nash’s technical expertise includes extensive experience in designing and supporting complex networks with a strong background in configuring, troubleshooting, and analyzing network systems. Nash has been with Cisco for more than 10 years and is currently an engineering manager
in the Enhanced Customer Aligned Testing Services (ECATS) group in the Advanced Services organization. Nash graduated with a bachelor of science degree in physics and computer science from the University of Bombay, India, and is a CCIE in routing and switching. He has written several white papers on various technologies and recently wrote the System Assurance Guide on High Availability Campus Network Design — Routed Access Using EIGRP or OSPF.
Patrice Bellagamba has been in the networking industry for more than 25 years and has spent more than 10 years in engineering development. He is a consulting engineer and a recognized expert in IP and MPLS technologies. He is one of the influencers in the development of MPLS and has led MPLS techtorials at Networkers in Europe since its
inception. He is also the inventor of the Embedded Event Manager (EEM) semaphore concept and is the designer of the VPLS-based solutions that this book describes. Patrice holds an engineering degree from the E´cole Supérieure d’Electricité, one of France’s prestigious Grandes E´coles and a top institution in the field of electrical and computer engineering. He has written several Cisco white papers on the use of MPLS technology.
