Designing Cisco Network Service Architectures

Transcription

1 ARCH Designing Cisco Network Service Architectures Volume 1 Version 1.2 Student Guide Text Part Number: ILSG Production Services:

2 Copyright 2004, Cisco Systems, Inc. All rights reserved. Cisco Systems has more than 200 offices in the following countries and regions. Addresses, phone numbers, and fax numbers are listed on the Cisco Web site at Argentina Australia Austria Belgium Brazil Bulgaria Canada Chile China PRC Colombia Costa Rica Croatia Cyprus Czech Republic Denmark Dubai, UAE Finland France Germany Greece Hong Kong SAR Hungary India Indonesia Ireland Israel Italy Japan Korea Luxembourg Malaysia Mexico The Netherlands New Zealand Norway Peru Philippines Poland Portugal Puerto Rico Romania Russia Saudi Arabia Scotland Singapore Slovakia Slovenia South Africa Spain Sweden Switzerland Taiwan Thailand Turkey Ukraine United Kingdom United States Venezuela Vietnam Zimbabwe Copyright 2004 Cisco Systems, Inc. All rights reserved. CCSP, the Cisco Square Bridge logo, Cisco Unity, Follow Me Browsing, FormShare, and StackWise are trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, and iquick Study are service marks of Cisco Systems, Inc.; and Aironet, ASIST, BPX, Catalyst, CCDA, CCDP, CCIE, CCIP, CCNA, CCNP, Cisco, the Cisco Certified Internetwork Expert logo, Cisco IOS, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Empowering the Internet Generation, Enterprise/Solver, EtherChannel, EtherFast, EtherSwitch, Fast Step, GigaDrive, GigaStack, HomeLink, Internet Quotient, IOS, IP/TV, iq Expertise, the iq logo, iq Net Readiness Scorecard, LightStream, Linksys, MeetingPlace, MGX, the Networkers logo, Networking Academy, Network Registrar, Packet, PIX, Post- Routing, Pre-Routing, ProConnect, RateMUX, Registrar, ScriptShare, SlideCast, SMARTnet, StrataView Plus, SwitchProbe, TeleRouter, The Fastest Way to Increase Your Internet Quotient, TransPath, and VCO are registered trademarks of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries. All other trademarks mentioned in this document or Website are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0406R) DISCLAIMER WARRANTY: THIS CONTENT IS BEING PROVIDED AS IS. CISCO MAKES AND YOU RECEIVE NO WARRANTIES IN CONNECTION WITH THE CONTENT PROVIDED HEREUNDER, EXPRESS, IMPLIED, STATUTORY OR IN ANY OTHER PROVISION OF THIS CONTENT OR COMMUNICATION BETWEEN CISCO AND YOU. CISCO SPECIFICALLY DISCLAIMS ALL IMPLIED WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. This learning product may contain early release content, and while Cisco believes it to be accurate, it falls subject to the disclaimer above.

3 Students, this letter describes important course evaluation access information! Welcome to Cisco Systems Learning. Through the Cisco Learning Partner Program, Cisco Systems is committed to bringing you the highest-quality training in the industry. Cisco learning products are designed to advance your professional goals and give you the expertise you need to build and maintain strategic networks. Cisco relies on customer feedback to guide business decisions; therefore, your valuable input will help shape future Cisco course curricula, products, and training offerings. We would appreciate a few minutes of your time to complete a brief Cisco online course evaluation of your instructor and the course materials in this student kit. On the final day of class, your instructor will provide you with a URL directing you to a short post-course evaluation. If there is no Internet access in the classroom, please complete the evaluation within the next 48 hours or as soon as you can access the web. On behalf of Cisco, thank you for choosing Cisco Learning Partners for your Internet technology training. Sincerely, Cisco Systems Learning

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5 Table of Contents Volume 1 Course Introduction 1 Overview 1 Learner Skills and Knowledge 2 Course Goal and Objectives 4 Course Flow 5 Additional References 6 Cisco Glossary of Terms 6 Your Training Curriculum 7 Introducing Cisco Network Service Architectures 1-1 Overview 1-1 Module Objectives 1-1 Introducing the Cisco AVVID Framework 1-3 Overview 1-3 Objectives 1-3 What Is the Cisco AVVID Framework? 1-4 What Are the Performance Concerns When Deploying an Enterprise Network? 1-7 What Are the Scalability Concerns When Deploying an Enterprise Network? 1-9 What Are the Availability Concerns When Deploying an Enterprise Network? 1-10 What Is the Cisco AVVID Network Infrastructure? 1-11 What Are the Cisco AVVID Intelligent Network Services? 1-13 What Are the Cisco AVVID Network Solutions? 1-15 Summary 1-16 Introducing the Enterprise Composite Network Model 1-17 Overview 1-17 Objectives 1-17 What Is the Enterprise Composite Network Model? 1-18 What Is the Enterprise Campus? 1-22 What Is the Enterprise Edge? 1-26 Service Provider Edge 1-30 Summary 1-32 Introducing the Network Design Methodology 1-33 Overview 1-33 Objectives 1-33 Network Design Process 1-34 Network Design Phases 1-35 Validating the Network Design 1-38 Summary 1-42 Module Summary 1-43 References 1-43 Module Self-Check 1-44 Module Self-Check Answer Key 1-49 Designing Enterprise Campus Networks 2-1 Overview 2-1 Module Objectives 2-1 Reviewing the Enterprise Network Design Methodology 2-3 Overview 2-3 Objectives 2-3 Designing the Campus within the Enterprise Composite Network Model 2-4 What are the Typical Requirements for an Enterprise Campus Network? 2-6 What is the Enterprise Campus Design Methodology? 2-8 Analyzing Network Traffic Patterns 2-10 Summary 2-12

6 Designing the Campus Infrastructure 2-13 Overview 2-13 Objectives 2-13 Designing the Logical Campus Network 2-14 Designing the Physical Campus Network 2-19 Selecting Data Link Layer or Multilayer Switching Solutions 2-25 Selecting Cisco Hardware and Software 2-31 Identifying an IP Addressing Strategy 2-33 Selecting Routing Protocols 2-37 When to Choose RIP or RIPv When to Choose IGRP 2-38 When to Choose EIGRP 2-39 When to Choose OSPF 2-40 When to Choose Integrated IS-IS 2-40 Selecting Areas or Networks 2-41 Proposing Enterprise Campus Designs 2-42 Summary 2-48 Designing the Server Farm 2-49 Overview 2-49 Objectives 2-49 What are the Design Requirements for the Server Farm? 2-50 Selecting Server Farm Infrastructure Architecture 2-52 Designing the Server Farm for Scalability 2-56 Considerations for Server Farm Security and Manageability 2-58 Summary 2-60 Module Summary 2-61 References 2-61 Module Self-Check 2-62 Module Self-Check Answer Key 2-65 Designing Enterprise Edge Connectivity 3-1 Overview 3-1 Module Objectives 3-1 Reviewing the Enterprise Edge Network Design Methodology 3-3 Overview 3-3 Objectives 3-3 What is the Enterprise Edge Design within the Enterprise Composite Model? 3-4 What are the Typical Requirements for the Enterprise Edge? 3-6 What is the Enterprise Edge Design Methodology? 3-8 Analyzing Network Traffic Patterns 3-10 Summary 3-12 Designing the Classic WAN Module 3-13 Overview 3-13 Objectives 3-13 What are the Enterprise Needs for the WAN? 3-14 Selecting the WAN Topology 3-15 Selecting a Service Provider 3-19 Selecting the Data Link Layer 3-21 Selecting the Physical Layer 3-23 Selecting WAN Features 3-24 Selecting Cisco Edge Routing Solutions 3-26 What are the Routing Protocol and IP Addressing Considerations? 3-29 Designing Enterprise WANs 3-34 Company Background 3-34 Summary 3-38 ii Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

7 Designing the Remote Access Module 3-39 Overview 3-39 Objectives 3-39 What are the Enterprise Needs for Remote Access? 3-40 Selecting the Remote-Access Type and Termination 3-43 Selecting the Remote-Access Physical Connectivity 3-45 Selecting the Remote-Access Protocol 3-47 Selecting Cisco Access Routing Solutions 3-48 Designing Enterprise Remote-Access Solutions 3-52 Summary 3-56 Designing the Internet Connectivity Module 3-57 Overview 3-57 Objectives 3-57 What are the Enterprise Requirements for the Internet? 3-58 Using NAT at the Enterprise Edge 3-60 Designing ISP Connectivity Solutions 3-61 Designing Internet Connectivity Solutions 3-64 Summary 3-66 Module Summary 3-67 References 3-67 Module Self-Check 3-68 Module Self-Check Answer Key 3-73 Designing Network Management Services 4-1 Overview 4-1 Module Objectives 4-1 Developing an Enterprise Network Management Strategy 4-3 Overview 4-3 Objectives 4-3 What are the Goals for Network Management? 4-4 What are the Network Management Policies and Procedures? 4-7 What are the Network Management Module Functions? 4-10 What is the Cisco Network Management Strategy? 4-11 What are the CiscoWorks Features? 4-12 What is the CiscoWorks LAN Management Solution? 4-14 What is the CiscoWorks Routed WAN Management Solution? 4-18 Summary 4-21 Designing the Network Management Architecture 4-23 Overview 4-23 Objectives 4-23 Considerations for Network Management Design 4-24 Recommendations for Network Management Deployment 4-28 Designing Network Management Solutions 4-33 Summary 4-42 Module Summary 4-43 References 4-43 Module Self-Check 4-44 Module Self-Check Answer Key 4-48 Designing High-Availability Services 5-1 Overview Module Objectives Reviewing High-Availability Features 5-3 Overview 5-3 Objectives 5-3 What are Network Requirements for High Availability? 5-4 What is Cisco IOS High-Availability Architecture? 5-7 Copyright 2004, Cisco Systems, Inc. Designing Cisco Network Service Architectures (ARCH) v1.2 iii

8 What is Fault Tolerance and Hardware Redundancy? 5-8 What are the Options for Layer 3 Redundancy? 5-13 What is Redundancy and Spanning Tree Protocol? 5-16 Summary 5-20 Designing High-Availability Enterprise Networks 5-21 Overview 5-21 Objectives 5-21 What are the Design Guidelines for High Availability? 5-22 What are the Best Practices for High-Availability Network Design? 5-29 What are the Enterprise Campus Design Guidelines for High Availability? 5-31 What are the Enterprise Edge Design Guidelines for High Availability? 5-35 Strategy for High-Availability Design 5-37 Summary 5-38 Module Summary 5-39 References 5-39 Module Self-Check 5-40 Module Self-Check Answer Key 5-43 Designing Security Services 6-1 Overview 6-1 Module Objectives 6-1 Evaluating Network Security Policies 6-3 Overview 6-3 Objectives 6-3 Network Vulnerabilities 6-4 Defining a Security Policy 6-6 Network Security as a Process 6-8 Securing the Network 6-8 Monitoring Security 6-9 Testing Security 6-9 Improving Security 6-9 Risk Assessment and Management 6-10 Summary 6-13 Reviewing Cisco Security Solutions 6-15 Overview 6-15 Objectives 6-15 Key Elements of Network Security 6-16 Network Security Attacks and Solutions 6-18 Firewall Design Options 6-30 Intrusion Detection System Design Options 6-37 Authentication, Authorization, and Accounting 6-40 IP Security 6-46 Device Security Options 6-50 Summary 6-55 Implementing Network Security Using the Cisco SAFE Security Blueprints 6-57 Overview 6-57 Objectives 6-57 Cisco SAFE Architecture Overview 6-58 SAFE Security Strategies for Small Networks 6-60 SAFE Security Strategies for Medium Networks 6-65 SAFE Security Strategies for Large Networks 6-72 SAFE Security Strategies for the Enterprise Edge 6-78 Summary 6-83 Module Summary 6-84 References 6-84 Module Self-Check 6-85 Module Self-Check Answer Key 6-89 iv Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

9 ARCH Course Introduction Overview In Designing Cisco Network Service Architectures (ARCH) v1.2, you will learn how to perform the conceptual, intermediate, and detailed design of a network infrastructure that supports desired network solutions over intelligent network services, to achieve effective performance, scalability, and availability. You will learn the fundamental aspects of campus and edge network design, network management, high availability, security, quality of service (QoS), and IP multicast. In addition, you will be able to design solutions for the network that are strategic to small, medium, and large enterprises, including virtual private networking, wireless, and IP telephony.

10 Learner Skills and Knowledge This subtopic lists the skills and knowledge that learners must possess to benefit fully from the course. The subtopic also includes recommended Cisco learning offerings that learners should complete to benefit fully from this course. Introduction to Cisco Networking Technologies (INTRO) Cisco IP Telephony (CIPT) Managing Cisco Network Security (MCNS) Implementing Cisco Multicast (MCAST) Learner Skills and Knowledge Cisco CCNA certification and Cisco CCNP certification or Completion of related courses: CCNA Basics Interconnecting Cisco Network Devices (ICND) Building Scalable Cisco Internetworks (BSCI) Building Cisco Multilayer Switched Networks (BCMSN) Building Cisco Remote Access Networks (BCRAN) Cisco Internetwork Troubleshooting (CIT) Designing for Cisco Internetwork Solutions (DESGN) IP Telephony Quality of Service (QOS) Security Technologies IP Multicast 2004 Cisco Systems, Inc. All rights reserved. ARCH v1.2 3 Before taking ARCH, learners should be familiar with internetworking technologies, Cisco products, and Cisco IOS features. Specifically, before attending this course learners should be able to meet these objectives: Design the necessary services to extend IP addresses using variable-length subnet masking (VLSM) and route summarization Implement appropriate networking routing protocols, such as Open Shortest Path First (OSPF), Enhanced Interior Gateway Routing Protocol (EIGRP), and Border Gateway Protocol (BGP) on an existing internetwork Redistribute routes between different routing protocols Select the required Cisco products and services that enable connectivity and traffic transport for a multilayer campus network Select the necessary services at each layer of the network to enable all users to obtain membership in multicast groups in a working enterprise network Control network traffic by implementing the necessary admission policy at each layer of the network topology 2 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

11 Identify the appropriate hardware and software solutions for a given set of WAN technology requirements, including permanent or dial-up access between a central campus, branch offices, and telecommuters Select Cisco equipment to establish appropriate WAN connections Enable protocols and technologies that allow traffic flow between multiple sites, while minimizing the amount of overhead traffic on each connection Implement QoS capabilities to ensure that mission-critical applications receive the required bandwidth within a given WAN topology Implement Cisco Voice over IP and IP telephony solutions Copyright 2004, Cisco Systems, Inc. Course Introduction 3

12 Course Goal and Objectives This topic describes the course goal and objectives. Course Goal To perform the conceptual, intermediate, and detailed design of a network infrastructure that supports the network solutions to achieve effective performance, scalability, and availability to meet the desired requirements Designing Cisco Network Service Architectures (ARCH v1.2) 2004 Cisco Systems, Inc. All rights reserved. ARCH v1.2 4 Upon completing this course, you will be able to meet these objectives: Present the Cisco AVVID framework, its segmentation of the network infrastructure, and intelligent network services to support key enterprise network applications and network solutions Create conceptual, intermediate, and detailed enterprise campus network and Enterprise Edge infrastructure designs that offer effective functionality, performance, scalability, and availability Create conceptual, intermediate, and detailed intelligent network service designs for network management, high availability, security, QoS, and IP multicast Create conceptual, intermediate, and detailed virtual private network designs Create conceptual, intermediate, and detailed wireless network designs Create conceptual, intermediate, and detailed IP telephony designs 4 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

13 Course Flow This topic presents the suggested flow of the course materials. Course Flow Day 1 Day 2 Day 3 Day 4 Day 5 A M Course Introduction Introducing Cisco Network Service Architectures Designing Enterprise Campus Networks Designing Enterprise Edge Connectivity Designing High- Availability Services Lunch Designing QoS Designing IP Multicast Services Designing IP Telephony Solutions P M Designing Enterprise Campus Networks (cont.) Designing Enterprise Edge Connectivity (cont.) Designing Network Management Services Designing Security Services Designing Virtual Private Networks Designing Enterprise Wireless Networks Wrap-Up 2004 Cisco Systems, Inc. All rights reserved. ARCH v1.2 5 The schedule reflects the recommended structure for this course. This structure allows enough time for the instructor to present the course information and for you to work through the lab activities. The exact timing of the subject materials and labs depends on the pace of your specific class. Copyright 2004, Cisco Systems, Inc. Course Introduction 5

14 Additional References This topic presents the Cisco icons and symbols used in this course and also information on where to find additional technical references. Cisco Icons and Symbols 2004 Cisco Systems, Inc. All rights reserved. ARCH v1.2 6 Cisco Glossary of Terms For additional information on Cisco terminology, refer to the Cisco Internetworking Terms and Acronyms glossary of terms at 6 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

15 Your Training Curriculum This topic presents the training curriculum for this course. Cisco Certifications 2004 Cisco Systems, Inc. All rights reserved. ARCH v1.2 7 This educational offering is a Cisco certification professional-level course. ARCH is the recommended method of preparation for the Cisco CCDP exam. The CCDP certification indicates a professional mastery of network design. This course enables learners, applying solid Cisco network solution models and best design practices, to provide viable, stable enterprise internetworking solutions. The course presents concepts and examples necessary to design enterprise campus networks and enterprise edge networks. Advanced network infrastructure technologies, such as Virtual Private Networks (VPNs) and wireless communications, are also covered. The course covers issues and considerations for fundamental intelligent network services, including security, network management, QoS, high availability, and bandwidth use optimization through IP multicasting and also design models for network solutions such as voice networking and content and storage networking. The CCDP exam is the final step necessary to achieve Cisco CCDP certification, following the Cisco CCNA and Cisco CCDA exams. A CCDP certification affirms possession of some of the skills needed to achieve Cisco CCIE certification. You are encouraged to join the Cisco Certification Community, a discussion forum open to anyone holding a valid Cisco Career Certification (such as Cisco CCIE, CCNA, CCDA, CCNP, CCDP, CCIP, or CCSP ). The Cisco Certification Community provides a gathering place for Cisco-certified professionals to share questions, suggestions, and information about Cisco Career Certification programs and other certification-related topics. For more information, visit Copyright 2004, Cisco Systems, Inc. Course Introduction 7

16 Cisco CCDP Career Certifications Expand Your Professional Options and Advance Your Career CCDP Professional-level recognition in Designing Cisco Network Service Architectures (ARCH) Expert Required Exam Recommended Training Through Cisco Learning Partners CCIE CCDP Professional Associate BSCI BCMSN ARCH Building Scalable Cisco Internetworks Building Cisco Multilayer Switched Networks Designing Cisco Network Service Architectures CCNA/CCDA CCDP Cisco Systems, Inc. All rights reserved. ARCH v Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

17 Module 1 Introducing Cisco Network Service Architectures Overview Large enterprises increasingly seek an enterprise-wide infrastructure to serve as a solid foundation for emerging applications such as IP telephony. The Cisco Architecture for Voice, Video and Integrated Data (AVVID) framework, with its open communications interface, is the basis of Cisco s enterprise network architecture. The framework is designed to support the operation of concurrent solutions operating over a single infrastructure designed, tested, and fully documented with scalability, performance, and availability that meets end-to-end enterprise requirements. Module Objectives Upon completing this module, you will be able to present the Cisco AVVID framework, its segmentation of the network infrastructure, and intelligent network services to support key enterprise network applications and network solutions. This ability includes being able to meet these objectives: Describe the Cisco AVVID framework and explain how it addresses enterprise network needs for performance, scalability, and availability Describe the Enterprise Composite Network Model used to design enterprise networks and explain how it addresses enterprise network needs for performance, scalability, and availability Describe the major steps of the network design process and explain how to validate your design before going live

18 1-2 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

19 Lesson 1 Introducing the Cisco AVVID Framework Overview Objectives The Cisco AVVID framework provides an enterprise with a foundation that combines IP connectivity with performance and availability. Layering application solutions, such as voice, video, or content delivery networks, requires changes to an existing infrastructure. The Cisco AVVID framework provides effective design principles and practices to plan those changes. Each enterprise network is different because it is built to accommodate different topologies, media, and features that the specific enterprises may deploy. The Cisco AVVID framework provides an infrastructure on which to offer intelligent services to support network solutions and business applications. Upon completing this lesson, you will be able to describe the Cisco AVVID framework and explain how it addresses enterprise network needs for performance, scalability, and availability. This ability includes being able to meet these objectives: Describe the major components of the Cisco AVVID framework and explain why an architecture is important for enterprise networks Describe performance concerns when deploying an enterprise network Describe scalability concerns when deploying an enterprise network Describe availability concerns when deploying an enterprise network Describe the network infrastructure component of the Cisco AVVID framework, and explain how it satisfies enterprise requirements for performance, scalability, and availability Describe the intelligent network services of the Cisco AVVID framework, and explain how those services support enterprise needs for performance, scalability, and availability Describe the Cisco AVVID network solutions offered to address the needs of enterprise applications

20 What Is the Cisco AVVID Framework? This topic describes the major components of the Cisco AVVID framework and explains why an architecture is important for enterprise networks. Cisco AVVID Framework 2004 Cisco Systems, Inc. All rights reserved. ARCH v Cisco AVVID provides the framework for the Internet business solutions of today. Cisco AVVID is an enterprise-wide, standards-based network architecture that provides a roadmap for combining business and technology strategies into a cohesive model. A network architecture is a roadmap and guide for ongoing network planning, design, and implementation. It provides a coherent framework that unifies disparate solutions onto a single foundation. The Cisco AVVID framework supports these key components: Common network infrastructure: This includes the hardware and software used to send, receive, and manage datagrams that are transmitted between end-user devices throughout the enterprise. Common network infrastructure includes the transmission media and devices that control transmission paths, including private and public transport media. Examples of these devices are routers, LAN switches, WAN switches, PBXs, and so on. Intelligent network services: These services allow the end user to operate in a controlled, secure environment in which differentiated services are provided. Intelligent network services essentially add intelligence to the network infrastructure beyond just moving a datagram between two points. Intelligent network services allow for application awareness. Intelligent network services include network management, high availability, security, quality of service (QoS), and IP multicast. 1-4 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

21 Network solutions: Network solutions include the hardware and software that use the network infrastructure and intelligent network services to their advantage. Network solutions allow enterprises to make business decisions about the business itself and also about networks and the technologies and applications that run on them. Network-based applications enable an enterprise organization to interact more effectively with customers, suppliers, partners, and employees. Customer service, commerce, supplier, and internal applications run over the network infrastructure enabled by intelligent network services. Some examples of network solutions are IP telephony, content networking, and storage networking. Note This course discusses the design implications of IP telephony. Content networking and storage networking design are not included in this course. Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-5

22 Benefits of Cisco AVVID Integration Intelligence Innovation Interoperability 2004 Cisco Systems, Inc. All rights reserved. ARCH v Cisco AVVID offers these benefits: Integration: By leveraging the Cisco AVVID framework and applying the network intelligence inherent in IP, organizations can enable comprehensive tools to improve productivity. Intelligence: Traffic prioritization and intelligent networking services maximize network efficiency for optimized application performance. Innovation: Customers have the ability to adapt quickly in a competitive and changing business environment. Interoperability: Standards-based hardware and software interfaces allow open integration, providing organizations with choice and flexibility. Combining network infrastructure and services with new applications, Cisco AVVID accelerates the integration of technology strategy with business activities. Cisco AVVID enables Internet business solutions for enterprises via the network infrastructure. 1-6 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

23 What Are the Performance Concerns When Deploying an Enterprise Network? This topic describes the performance concerns when deploying an enterprise network. Primary Concern of Network Deployment: Performance Responsiveness Important to users Throughput Important to operational management Utilization Important to executive management 2004 Cisco Systems, Inc. All rights reserved. ARCH v While specific devices or applications may promise performance, effective performance is achieved only by considering and optimizing each component. Only a cohesive, integrated, and optimized network can ensure the best network performance. Performance might be the least understood term in networking. Typically, performance is defined as throughput and packets per second (pps). These are easy numbers to gauge and report, but these values relate to a single switch or router and make no sense when measuring an entire network. For example, one can state that a network should perform at 10,000 pps, but testing over the network might yield only 5000 pps. What happened? In fact, the network might consist of Mbps (T1) WAN links with traffic shaping enabled, which in turn limits the packet rate through the entire network. In addition, forwarding traffic at that rate might have an impact on the processor loads, limiting the overall throughput performance and placing the router at risk of not having enough resources either to converge following a failure in the network or to enable additional features. The point is that there is no one metric for determining performance. Instead, gauge network performance by these three metrics: Responsiveness: This indicates how users or consumers perceive the performance of their applications. Responsiveness is affected by link speeds, congestion, and features, and includes device and protocol responses. This is the most important metric in the network. If an application does not respond in an acceptable time, it does not matter how fast the network claims to be. This metric changes based on how an application responds to changes in the network. For example, many applications use TCP, which slows the transmission rate into the network if too much congestion or loss is present in the network. Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-7

24 Throughput: This specifies the rate of information arriving at, and possibly passing through, a particular point in a network system. Throughput is closely related to utilization. As utilization increases, throughput approaches the theoretical maximum until driven to congestive collapse. Typically, throughput is measured in pps, kbps, Mbps, and Gbps. Utilization: This measures the use of a particular resource over time. This measure is usually expressed as a percentage, where the usage of a resource is compared with its maximum operational capacity. Through utilization measures, you can identify congestion (or potential congestion) throughout the network. You can also identify underutilized resources. Utilization is the principle measure to determine how full the network pipes (links) are. Analyzing CPU, interface, queuing, and other system-related capacity measurements allows you to determine the extent to which network system resources are being consumed. High utilization is not necessarily bad. Low utilization may indicate traffic flows in unexpected places. As lines become overutilized, the effects can become significant. Overutilization on a link occurs when there is consistently more traffic that needs to pass through more of an interface than it can handle. Ultimately, there will be excessive queuing delays and even packet loss. Sudden jumps in resource utilization can indicate a fault condition. 1-8 Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

25 What Are the Scalability Concerns When Deploying an Enterprise Network? This topic describes scalability concerns when deploying an enterprise network. Primary Concern of Network Deployment: Scalability Scalability Requirements Topology Support changes with minimum reconfiguration Addressing Allow route summarization Routing protocols Accommodate changes without massive redesign 2004 Cisco Systems, Inc. All rights reserved. ARCH v A network must be able to scale from where it is today to where it might be in the future. For example, a network administrator might need to design the WAN to support only 50 branch offices. However, over the course of a year, 50 more branches might require connectivity. The design, IP address management, features, and WAN link speeds must all be able to accommodate this need for added connectivity without massive redesign of the network. When designing an enterprise network, you should try to implement some basic principles throughout the network to improve scalability. Specialization of devices and card modules for specific functions makes it easy to upgrade each device as the network grows. Parallelism in the network design improves overall network performance. By implementing a hierarchy, you will achieve more control and manageability of the network. Specific network scalability concerns include the following: Topology: Network topology must be such that additions or subtractions to the network do not cause major reconfigurations, create instability, affect deterministic performance, or adversely affect availability levels. Addressing: Distribution of IP addresses should facilitate route summarization. Additionally, it should be possible to create new subnets with a minimum impact on the addressing scheme and router load. Routing protocols: The routing protocol of choice must be able to accommodate additions, deletions, and changes without a massive redesign. Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-9

26 What Are the Availability Concerns When Deploying an Enterprise Network? This topic describes availability concerns when deploying an enterprise network. Primary Concern of Network Deployment: Availability Device fault tolerance and redundancy Link redundancy Protocol resiliency Network capacity design 2004 Cisco Systems, Inc. All rights reserved. ARCH v A major concern for network managers is how available the network is and how impervious it is to network changes. A network that takes 10 seconds to converge is clearly superior to one that takes 1 minute to converge. To the user, the network is down regardless of whether an application went down, a router died, or a piece of fiber was cut. For this reason, availability must be viewed from the perspective of the user. Key availability issues to address include the following: Device fault tolerance and redundancy: This is often the first level of availability in the network. Fault-tolerant devices provide a high level of reliability. Cisco offers options for redundant supervisor engines and dual power supplies, which provide the first backstop against a network failure. Link redundancy: Link redundancy is critical in the network and provides a high level of reliability in the event of a link failure. However, while some redundancy is good, more redundancy is not necessarily better. Protocol resiliency: Good design practices indicate how and when to use protocol redundancy, including load sharing, convergence speed, and path redundancy handling. Network capacity design: Good design practices consider capacity planning. How much traffic can a connection handle in the worst-case scenario? Network designers must ascertain whether a link can handle twice the traffic when a redundant link fails Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

27 What Is the Cisco AVVID Network Infrastructure? This topic describes the network infrastructure component of the Cisco AVVID framework, and explains how it meets enterprise needs for performance, scalability, and availability. Cisco AVVID Network Infrastructure Components 2004 Cisco Systems, Inc. All rights reserved. ARCH v The Cisco AVVID framework consists of several building blocks that deliver solutions to accelerate the enterprise. The network infrastructure components include clients and servers, network platforms, and intelligent network services. The Cisco AVVID network infrastructure consists of these hardware components: Clients and application servers: Network clients include workstations (both fixed and portable), IP Phones, and wireless devices. Application servers provide services to clients and may be located in a data center or other easily accessible network location. Network platforms: The network platforms comprise routers, gateways, switches, servers, firewalls, and other devices. This component of the architecture provides the basis for a complete networking solution. Intelligent network services: Intelligent network services include the platforms, network services, appliances, and management that allow business rules and policies to positively affect network performance. The Cisco AVVID network infrastructure solution provides an enterprise foundation that combines IP connectivity with high performance and availability. Although layering application solutions such as voice, video, or content delivery networks require changes to the network infrastructure, this infrastructure provides a basis for good design principles and practices. Each network is different because it is built to accommodate different topologies (mesh or huband-spoke), WAN technologies (such as Frame Relay, ATM, or PPP), and networks (LAN, WAN, or metropolitan-area network [MAN]) that enterprises deploy. Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-11

28 Network managers who design and build networks to support solutions such as voice and video must first consider the components that allow networks to operate properly. Thus, the network device often becomes the focus of design decisions. However, a single device whether a switch, router, or other networking device is only a component of the overall network. How the devices connect, what features and protocols are used, and how they are used form the foundation for the services that run on top of the network. If the foundation is unstable, layering solutions over the network can create problems. By laying the foundation for basic connectivity and protocol deployment, the Cisco AVVID network infrastructure solution addresses the three primary concerns of network deployment: performance, scalability, and availability Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

29 What Are the Cisco AVVID Intelligent Network Services? This topic describes the intelligent network services of the Cisco AVVID framework and explains how those services meet enterprise needs for performance, scalability, and availability. Cisco AVVID Intelligent Network Services 2004 Cisco Systems, Inc. All rights reserved. ARCH v Cisco AVVID network infrastructure supports the key intelligent network services, which comprise numerous networking technologies and topologies, with a corresponding large number of possible designs and architectures. The net result is a blueprint that blends equipment, features, and management tools that match business criteria. Cisco deploys these intelligent network services to keep the network at peak performance: Network management: This service provides a number of related network management tools built on a Common Management Foundation (CMF). Tools include the LAN Management Solution (LMS) for advanced management of Catalyst multilayer switches; the Routed WAN Management Solution (RWAN) for monitoring traffic management and providing access control to administer the routed infrastructure of multiservice networks; the Service Management Solution for managing and monitoring service level agreements; and the Virtual Private Network (VPN)/Security Management Solution for optimizing VPN performance and security administration. High availability: This service refines design and tools to ensure end-to-end availability for services, clients, and sessions. Tools include reliable, fault-tolerant network devices to automatically identify and overcome failures, and resilient network technologies, such as Hot Standby Router Protocol (HSRP), to bring resilience to the critical junction between hosts and backbone links. Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-13

30 Security: This service ensures the security of the network through authentication, encryption, and failover. Security features include application-based filtering (contextbased access control), intrusion detection in the network and at hosts, defense against network attacks, per-user authentication and authorization, and real-time alerts. QoS: This service manages the delay, delay variation (jitter), bandwidth, and packet loss parameters on a network to meet the diverse needs of voice, video, and data applications. QoS features provide functionality such as network-based application recognition (NBAR) for classifying traffic on an applications basis, a Service Assurance Agent (SAA) for endto-end QoS measurements, and Resource Reservation Protocol (RSVP) signaling for admission control and reservation of resources. IP multicast: This service provides bandwidth-conserving technology that reduces traffic by simultaneously delivering a single stream of information to thousands of end-system clients. Multicasting enables distribution of videoconferencing, corporate communications, distance learning, distribution of software, and other applications. Multicast packets are replicated in the network by Cisco routers enabled with Protocol Independent Multicast (PIM) and other supporting multicast protocols resulting in an efficient delivery of data to multiple receivers. Cisco AVVID Intelligent Network Services Meet Enterprise Needs Performance Scalability Availability Network Management High Availability Security Quality of Service IP Multicast Enhances performance when preemptive Enhances performance of selected applications Enhances application performance Increases support of preferred applications Increases scalability of existing network resources Monitors device and network availability Makes network more available Makes applications and data more available Makes critical applications more available Makes applications more available 2004 Cisco Systems, Inc. All rights reserved. ARCH v The figure describes how the Cisco AVVID intelligent network services meet enterprise network needs for performance, scalability, and availability Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

31 What Are the Cisco AVVID Network Solutions? This topic describes the Cisco AVVID network solutions that Cisco offers to address enterprise application needs. Cisco AVVID Network Solutions 2004 Cisco Systems, Inc. All rights reserved. ARCH v The Cisco AVVID framework provides a foundation for applications and solutions. Third-party companies provide solutions through the Cisco AVVID Partner Program, while Cisco provides the following solutions: VPN (part of the Enterprise Edge): VPNs use advanced encryption and tunneling to permit organizations to establish secure, end-to-end private network connections over thirdparty networks, such as the Internet or extranets. Wireless (part of the Campus Infrastructure): Wireless IP technology creates anytime, anywhere connections to the Internet and enterprise networks. In a campus environment or distant mobile location, wireless technology allows users to be constantly connected as they move between wireless cells, unconstrained by direct physical connections. IP telephony: The convergence of voice, video, and data on a single IP network is changing the way enterprises communicate. Convergence on a single network infrastructure lowers total network costs and optimizes enterprise communications. Content networking: Content networking optimizes website performance and content delivery by positioning content near consumers in anticipation of use. Storage networking: Driven by workforce collaboration, e-commerce, and e-learning, storage networking has emerged as an important networking application. Cisco storage networking solutions provide high-capacity, low-latency networking for disaster recovery, data replication, and storage consolidation. Note This course discusses the design implications of IP telephony. Content networking and storage networking design are not included in this course. Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-15

32 Summary This topic summarizes the key points discussed in this lesson. Summary Cisco AVVID is an enterprise-wide, standards-based network architecture that provides a roadmap for combining business and technology strategies into a cohesive model. While specific devices or applications may promise performance, effective performance is achieved only by considering and optimizing each component. Only a cohesive, integrated, and optimized network can ensure the best network performance. A network must be able to scale from where it is today to where it might be in the future. The design, IP address management, features, and WAN link speeds must all be able to provide connectivity and additions without massive redesign of the network Cisco Systems, Inc. All rights reserved. ARCH v Summary (Cont.) A major concern for network managers is how available the network is or how impervious it is to network changes. The Cisco AVVID network infrastructure component includes clients and servers, network platforms, and intelligent network services. Cisco AVVID network infrastructure supports the key intelligent network services, which comprise numerous networking technologies and topologies, with a corresponding large number of possible designs and architectures. The Cisco AVVID framework provides a foundation for applications and solutions. Cisco provides some solutions, while third-party companies provide solutions through the Cisco AVVID Partner Program Cisco Systems, Inc. All rights reserved. ARCH v Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

33 Lesson 2 Introducing the Enterprise Composite Network Model Overview Objectives The Enterprise Composite Network Model provides a framework for designing the components of an enterprise network. The model relies on the principles of the Cisco AVVID, which provides a framework for the solutions presented in this course. Upon completing this lesson, you will be able to describe the Enterprise Composite Network Model used to design enterprise networks and explain how it addresses enterprise network needs for performance, scalability, and availability. This ability includes being able to meet these objectives: Describe the Enterprise Composite Network Model and explain how it addresses enterprise network modularity Describe the modules that comprise an enterprise campus network, and explain how the Enterprise Campus functional area meets the need for performance, scalability, and availability Describe the components and functionality at the Enterprise Edge, and explain how the Enterprise Edge functional area meets the need for performance, scalability, and availability Describe the components and functionality at the Service Provider Edge, and explain how the Service Provider Edge functional area meets the need for performance, scalability, and availability

34 What Is the Enterprise Composite Network Model? This topic describes the Enterprise Composite Network Model and explains how it addresses enterprise network requirements for modularity. Hierarchical Model 2004 Cisco Systems, Inc. All rights reserved. ARCH v The Enterprise Composite Network Model provides a modular framework for designing networks. The modularity within the model allows flexibility in network design and facilitates implementation and troubleshooting. Nearly a decade ago, Cisco introduced a hierarchical design model as a tool for network designers to approach network design from physical, logical, and functional viewpoints. The hierarchical model divided networks into these layers: Access layer: The access layer is used to grant user access to network devices. At a network campus, the access layer incorporates shared, switched, or subnetted LAN devices with ports available to workstations and servers. In the WAN environment, the access layer can provide sites with access to the corporate network using a WAN technology. Distribution layer: The distribution layer aggregates the wiring closets and uses data link layer switching and multilayer switching to segment workgroups and isolate network problems, preventing workgroups from having an impact on the core layer. Routing and packet manipulation occur in the distribution layer. Core layer: The core layer is a high-speed backbone and is designed to switch packets as fast as possible. Because the core is critical for connectivity, it must provide a high level of availability and must adapt to changes very quickly. The hierarchical module was useful, but had weaknesses when implementing large, complex enterprise networks Designing Cisco Network Service Architectures (ARCH) v1.2 Copyright 2004, Cisco Systems, Inc.

35 Enterprise Composite Network Model Functional Areas 2004 Cisco Systems, Inc. All rights reserved. ARCH v The Enterprise Composite Network Model introduces additional modularity into the network structure. The entire network is divided into functional areas that contain the access, distribution, and core layers of the hierarchical model. The Enterprise Composite Network Model contains three major functional areas: Enterprise Campus: This functional area contains the modules required to build a hierarchical, highly robust campus network that offers performance, scalability, and availability. This Enterprise Campus contains the network elements required for independent operation within a single campus. This functional area does not offer remote connections or Internet access. A campus is defined as one or more buildings, with multiple virtual and physical networks, connected across a high-performance, multilayer-switched backbone. Enterprise Edge: This functional area aggregates connectivity from the various elements at the edge of the enterprise network. The Enterprise Edge functional area filters traffic from the edge modules and routes it into the Enterprise Campus functional area. The Enterprise Edge functional area contains all of the network elements for efficient and secure communication between the Enterprise Campus and remote locations, remote users, and the Internet. Service Provider Edge: This functional area provides functionality implemented by service providers. The Service Provider Edge functional area enables communications with other networks using different WAN technologies and Internet service providers (ISPs). Copyright 2004, Cisco Systems, Inc. Introducing Cisco Network Service Architectures 1-19