Cisco Systems. Designing Cisco Network Service Architectures. Volume 1. Student Guide

454 Pages·9.665 MB·English

ARCH
Designing Cisco Network
Service Architectures
Volume 1
Version 2.0

Student Guide

05.08.07
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Table of Contents
Volume 1
Course Introduction.......................................................................................................... 1
Overview...............................................................................................................................................1
Learner Skills and Knowledge.......................................................................................................1
Course Goal and Objectives.................................................................................................................3
Course Flow..........................................................................................................................................4
Additional References...........................................................................................................................5
Cisco Glossary of Terms................................................................................................................6
Your Training Curriculum......................................................................................................................7
Cisco SONA and the Cisco Enterprise Architectures.................................................1-1
Overview............................................................................................................................................1-1
Module Objectives.......................................................................................................................1-1
Reviewing SONA and the Cisco Enterprise Architectures 1-3
Overview............................................................................................................................................1-3
Objectives....................................................................................................................................1-3
The Hierarchical Model......................................................................................................................1-4
Example Hierarchical Network....................................................................................................1-5
Review of Cisco SONA......................................................................................................................1-6
Benefits of SONA........................................................................................................................1-7
Example: Cisco Enterprise Campus Architecture.......................................................................1-8
Review of Cisco Enterprise Architectures.........................................................................................1-9
Infrastructure Services.....................................................................................................................1-11
Application Layer.............................................................................................................................1-13
Summary..........................................................................................................................................1-14
Reviewing the Cisco PPDIOO Approach 1-15
Overview..........................................................................................................................................1-15
Objectives..................................................................................................................................1-15
PPDIOO Network Lifecycle Approach.............................................................................................1-16
Benefits of the Lifecycle Approach............................................................................................1-18
Using the Design Methodology under PPDIOO..............................................................................1-20
Identifying Customer Requirements..........................................................................................1-21
Characterizing the Existing Network and Sites.........................................................................1-22
Designing the Topology and Network Solutions.......................................................................1-23
Example: Dividing the Network into Areas................................................................................1-24
Summary..........................................................................................................................................1-25
References................................................................................................................................1-25
Module Summary.............................................................................................................................1-27
References................................................................................................................................1-28
Module Self-Check..........................................................................................................................1-29
Module Self-Check Answer Key...............................................................................................1-32
Enterprise Campus Network Design 2-1
Overview 2-1
Module Objectives 2-1
High Availability in the Enterprise Campus 2-3
Overview 2-3
Objectives 2-3
Enterprise Campus Infrastructure Review 2-4
Access Layer 2-4
Distribution Layer 2-6
Core Layer 2-7
High Availability Considerations 2-9
Implement Optimal Redundancy 2-9
Provide Alternate Paths 12-0
Avoid Single Points of Failure 2-11
Cisco Nonstop Forwarding with Stateful Switchover 2-12
Cisco IOS Software Modularity Architecture 2-15
Summary 2-18
Layer 2 Design Recommendations 2-19
Overview 2-19
Objectives 2-19
Recommended Practices for Spanning Tree Configuration 2-20
Spanning Tree Toolkit 2-21
Spanning Tree Standards and Features 2-23
Layer 2 Hardening 2-25
Recommended Practices for Trunk Configuration 2-27
VLAN Trunk Protocol 2-28
Dynamic Trunk Protocol 2-29
Recommended Practices for UDLD Configuration 2-31
Recommended Practices for EtherChannel 2-32
Port Aggregation Protocol 2-33
Link Aggregation Control Protocol 2-34
Summary 2-35
Layer 3 Design Recommendations 2-37
Overview 2-37
Objectives 2-37
Managing Oversubscription and Bandwidth 2-38
Bandwidth Management with EtherChannel 2-39
Bandwidth Management with 10 Gigabit Interfaces 2-40
Link Load Balancing 2-41
EtherChannel Load Balancing 2-43
Routing Protocol Design 2-44
Build Redundant Triangles 2-45
Peer Only on Transit Links 2-46
Summarize at Distribution Layer 2-47
First Hop Redundancy 2-48
Preempt Delay Tuning 2-50
Overview of Gateway Load Balancing Protocol 2-51
Optimizing FHRP Convergence 2-54
Summary 2-55
Layer 2 to Layer 3 Boundary Design 2-57
Overview 2-57
Objectives 2-57
Layer 2 to Layer 3 Boundary Design Models 2-58
Layer 2 Distribution Switch Interconnection 2-58
Layer 3 Distribution Switch Interconnection 2-59
Layer 3 Distribution Switch Interconnection 2-59
Layer 3 Access to Distribution Interconnection 2-61
Potential Design Issues 2-65
Daisy Chaining Access Layer Switches 2-65
Too Much Redundancy 2-68
Too Little Redundancy 2-69
Asymmetric Routing (Unicast Flooding) 2-72
Summary 2-74
Infrastructure Services Considerations 2-75
Overview 2-75
Objectives 2-75
IP Telephony Considerations 2-76
IP Telephony Extends the Network Edge 2-77
PoE Requirements 2-78
Multi-VLAN Access Port 2-85
QoS Considerations 2-87
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Recommended Practices for QoS 2-88
Transmit Queue Congestion 2-89
QoS Role in the Campus 2-90
Campus QoS Design Considerations 2-91
Cisco Catalyst Integrated Security Features 2-92
Port Security Prevents MAC-Based Attacks 2-93
DHCP Snooping Protects Against Rogue and Malicious DHCP Server 2-94
Dynamic ARP Inspection Protects Against ARP Poisoning 2-95
IP Source Guard Protects Against Spoofed IP Addresses 2-96
Example Catalyst Integrated Security Feature Configuration 2-97
Summary 2-98
Module Summary 2-99
References 2-100
Module Self-Check 2-101
Answer Key 2-107
Advanced Addressing and Routing Design 3-1
Overview 3-1
Module Objectives 3-1
Advanced Addressing Design 3-3
Overview 3-3
Objectives 3-3
IP Address Planning as a Foundation 3-4
Summarizable Blocks of Addresses 3-5
Changing IP Addressing Needs 3-7
Planning Addresses 3-8
Applications of Summarizable Addressing 3-9
Implementing Role-Based Addressing 3-10
Bit Splitting for Route Summarization 12
Example: Bit-Splitting for Area 1 3-13
Addressing for VPN Clients 3-14
NAT in the Enterprise 3-15
NAT with External Partners 3-16
Summary 3-18
Advanced Routing Design 3-19
Overview 3-19
Objectives 3-19
Route Summarization and Default Routing 3-20
Originating Default 3-21
Stub Areas and Default Route 3-22
Route Filtering in the Network Design 3-24
Avoid Inappropriate Transit Traffic 3-24
Defensive Filtering 3-25
Designing Redistribution 3-27
Filtered Redistribution 3-28
Migrating Between Routing Protocols 3-29
Summary 3-31
Scalable EIGRP Design 3-33
Overview 3-33
Objectives 3-33
Scaling EIGRP Designs 3-34
EIGRP Fast Convergence 3-35
EIGRP Fast Convergence Metrics 3-36
Scaling EIGRP with Multiple Autonomous Systems 3-37
Example: External Route Redistribution Issue 3-38
Filtering EIGRP Redistribution with Route Tags 3-39
Filtering EIGRP Routing Updates with Inbound Route Tags 3-40
Example: Queries with Multiple EIGRP Autonomous Systems 3-41
© 2007 Cisco Systems, Inc. Designing Cisco Network Service Architectures (ARCH) v2.0 iii
Reasons for Multiple EIGRP Autonomous Systems 3-42
Summary 3-43
References 3-43
Scalable OSPF Design 3-45
Overview 3-45
Objectives 3-45
Factors Influencing OSPF Scalability 3-46
Number of Adjacent Neighbors and Designated Routers 3-47
Routing Information in Area and Domain 3-48
Designing Areas 3-50
Area Size: How Many Routers in Area? 3-51
OSPF Hierarchy 3-53
Area and Domain Summarization 3-54
OSPF Hub-and-Spoke Design 3-55
Number of Areas in OSPF Hub-and-Spoke Design 3-56
Issues with Hub-and-Spoke Design 3-57
OSPF Hub-and-Spoke Network Types 3-58
OSPF Area Border Connection Behavior 3-59
OSPF Area Border Connection Considerations 3-60
OSPF Area Filtering 3-61
Application of Interarea Filtering 3-62
Full-Mesh Topology and Mesh Group 3-63
OSPF Flood Reduction 3-64
Fast Convergence in OSPF 3-65
Fast Convergence with Fast Hellos 3-66
Fast Convergence with SPF 3-67
Overview of OSPF Incremental SPF 3-68
Incremental SPF Convergence Times 3-69
Bidirectional Forwarding Detection 3-70
Summary 3-71
References 3-71
Scalable BGP Design 3-73
Overview 3-73
Objectives 3-73
Scaling BGP Designs 3-74
Full Mesh IBGP Scalability 3-75
Scaling IBGP with Route Reflectors 3-76
BGP Route Reflector Definitions 3-77
Additional Route Reflector Definitions 3-78
Route Reflector Basics 3-79
Scaling IBGP with Confederations 3-80
BGP Confederation Definitions 3-81
Confederation Basics 3-82
Confederations Reduce Meshing 3-83
Deploying Confederations 3-85
Summary 3-88
References 3-88
Module Summary 3-89
References 3-89
Module Self-Check 3-91
Module Self-Check Answer Key 3-94
iv Designing Cisco Network Service Architectures (ARCH) v2.0 © 2007 Cisco Systems, Inc.
Advanced WAN Services Design Considerations 4-1
Overview 4-1
Objectives 4-1
Optical Technologies for WANs 4-3
Overview 4-3
Objectives 4-3
Advanced WAN Service Layers 4-4
Enterprise Optical Interconnections 4-5
SONET/SDH Overview 4-6
Enterprise View of SONET 4-8
WDM Overview 4-9
CWDM Technical Overview 4-9
DWDM Technical Overview 4-11
RPR Overview 4-13
Summary 4-15
Metro Ethernet and MPLS VPN Technologies 4-17
Overview 4-17
Objectives 4-17
Metro Ethernet Overview 4-18
Metro Ethernet Services Model 4-18
Metro Ethernet Architecture 4-19
Metro Ethernet LAN Services 4-21
802.1Q Tunneling and QoS Across the Network 4-29
Choosing the Right Service 4-30
VPLS Overview 4-31
VPLS Architecture Model 4-32
VPLS in the Enterprise 4-33
H-VPLS Overview 4-35
Scaling VPLS 4-36
QoS Issues with EMS or VPLS 4-38
EMS or VPLS and Routing Implications 4-39
VPLS and IP Multicast 4-40
VPLS Availability 4-41
MPLS VPN Overview 4-42
Customer Considerations with MPLS VPNs 4-43
Summary 4-47
Advanced WAN Service Implementations 4-49
Overview 4-49
Objectives 4-49
Advanced WAN Service Selection 4-50
Business Risk Assessment 4-51
WAN Features and Requirements 4-53
SLA Overview 4-55
SLA Monitoring 4-57
Summary 4-58
Module Summary 4-59
References 4-59
Module Self-Check 4-61
Module Self-Check Answer Key 4-65
Enterprise Data Center Design 5-1
Overview 5-1
Module Objectives 5-1
© 2007 Cisco Systems, Inc. Designing Cisco Network Service Architectures (ARCH) v2.0 v
Core and Aggregation Layer Design 5-3
Overview 5-3
Objectives 5-3
Data Center Architecture Overview 5-4
Benefits of the Three Layer Model 5-5
Data Center Core Layer Design 5-6
Layer 3 Characteristics for the Data Center Core 5-7
OSPF Routing Protocol Design Recommendations 5-8
EIGRP Routing Protocol Design Recommendations 5-9
Aggregation Layer Design 5-10
Scaling the Aggregation Layer 5-11
Scaling the Aggregation Layer 5-11
STP Design 5-13
Integrated Service Modules 5-14
Service Module Placement Consideration 5-15
Active STP, HSRP, and Service Context Alignment 5-16
Active/Standby Service Module Design 5-17
Active/Active Service Module Design 5-18
Establishing Inbound Path Preference 5-19
Using VRFs in the Data Center 5-20
Summary 5-21
Access Layer Design 5-23
Overview 5-23
Objectives 5-23
Overview of the Data Center Access Layer 5-24
Layer 2 Looped Designs 5-25
Layer 2 Looped Topologies 5-26
Layer 2 Looped Design Issues 5-27
Layer 2 Loop-Free Designs 5-28
Loop-Free Topologies 5-29
Example: Loop-Free U Design and Layer 2 Service Modules 5-30
Example: Loop-Free U Design and ACE Service Module 5-31
Layer 2 FlexLink Designs 5-32
FlexLinks Issues and Considerations 5-33
Comparison of Layer 2 Access Designs 5-35
Layer 3 Access Layer Designs 5-36
Multicast Source Support 5-37
Benefits of Layer 3 Access 5-38
Drawbacks of Layer 3 Access 5-39
Blade Server Overview 5-40
Blade Server Connectivity Options 5-42
Blade Server Trunk Failover Feature 5-45
Summary 5-46
Scaling the Data Center Architecture 5-49
Overview 5-49
Objectives 5-49
Modular Compared to 1RU Designs 5-50
Cabinet Design with 1RU Switching 5-52
Example: Network Topology with 1RU Switching Model..........................................................5-53
Cabinet Design with Modular Access Switches........................................................................5-54
Example: Network Topology with Modular Access Switches...................................................5-55
Server NIC Density...................................................................................................................5-56
Hybrid Example with Separate OOB.........................................................................................5-57
Oversubscription and Uplinks...................................................................................................5-58
Scaling Bandwidth and Uplink Density............................................................................................5-59
EtherChannel Utilization Optimization with Load Balancing.....................................................5-59
EtherChannel Utilization Optimization with Min-Links..............................................................5-60
Scaling with Service Layer Switches........................................................................................5-61
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Scaling Service on ACE Modules.............................................................................................5-62
Summary..........................................................................................................................................5-63
Spanning Tree and High Availability 5-65
Overview..........................................................................................................................................5-65
Objectives..................................................................................................................................5-65
STP Scalability.................................................................................................................................5-66
Spanning Tree Protocols in the Data Center............................................................................5-67
Spanning Tree Protocol Scaling...............................................................................................5-68
STP Logical Interfaces..............................................................................................................5-69
STP Scaling with 120 System Wide VLANs.............................................................................5-71
STP in 1RU Designs.................................................................................................................5-73
STP Scaling Design Guidelines................................................................................................5-74
High Availability in the Data Center.................................................................................................5-75
Common NIC Teaming Configurations.....................................................................................5-76
High Availability and Failover Times.........................................................................................5-78
High Availability and NSF with SSO..........................................................................................5-80
Summary..........................................................................................................................................5-82
Module Summary.............................................................................................................................5-83
References................................................................................................................................5-83
Module Self-Check..........................................................................................................................5-85
Module Self-Check Answer Key...............................................................................................5-90
Design Considerations for Storage Area Networks....................................................6-1
Overview............................................................................................................................................6-1
Objectives....................................................................................................................................6-1
SAN Components and Technologies 6-3
Overview............................................................................................................................................6-3
Objectives....................................................................................................................................6-3
SAN Overview and Components.......................................................................................................6-4
SAN Components.......................................................................................................................6-6
Storage Topologies............................................................................................................................6-9
Direct Attached Storage..............................................................................................................6-9
Network Attached Storage........................................................................................................6-10
SAN Technologies...........................................................................................................................6-11
SCSI Overview..........................................................................................................................6-11
Fibre Channel Overview............................................................................................................6-12
Fibre Channel Communications Model.....................................................................................6-14
Virtual SAN................................................................................................................................6-16
Inter-VSAN Routing...................................................................................................................6-17
Fabric Shortest Path First.........................................................................................................6-18
Zoning.......................................................................................................................................6-19
FICON.......................................................................................................................................6-20
SANTap.....................................................................................................................................6-21
Summary..........................................................................................................................................6-22
SAN and SAN Extension Design 6-23
Overview..........................................................................................................................................6-23
Objectives..................................................................................................................................6-23
SAN Design Factors........................................................................................................................6-24
SAN Designs with the Cisco MDS 9000 Family........................................................................6-27
Single Switch Design – Collapsed Core..........................................................................................6-29
Small Scale Dual Fabric............................................................................................................6-30
Medium Scale Dual Fabric........................................................................................................6-31
Large Scale Dual Fabric............................................................................................................6-32
SAN Extension.................................................................................................................................6-33
SAN Extension Protocols..........................................................................................................6-34
Fibre Channel over IP...............................................................................................................6-35
iSCSI.........................................................................................................................................6-36
SAN Extension Developments..................................................................................................6-38
© 2007 Cisco Systems, Inc. Designing Cisco Network Service Architectures (ARCH) v2.0 vii
High Availability SAN Extension...............................................................................................6-39
Summary.........................................................................................................................................6-40
Module Summary............................................................................................................................6-41
References................................................................................................................................6-41
Module Self-Check..........................................................................................................................6-43
Module Self-Check Answer Key...............................................................................................6-45

viii Designing Cisco Network Service Architectures (ARCH) v2.0 © 2007 Cisco Systems, Inc.