Content Networking Fundamentals Silvano Da Ros Cisco Press 800 East 96th Street Indianapolis, IN 46240 USA
X Contents Introduction Part I Overview of Content Networking 3 Chapter 1 Introducing Content Networking 5 Defining Content Networking 5 Understanding the Underlying Technologies 7 Purpose and Goals 10 xx Scalability and Availability 10 Scaling the Application 10 Increasing Application Availability 11 Bandwidth and Response Times 13 Customization and Prioritization 14 Security, Auditing, and Monitoring 15 Securing Content on the Network 15 Securing Client and Origin Server Content 17 Monitoring, Administration, and Reporting 18 Cisco Content Networking Solutions 20 Content Switching 20 Server Load Balancing (SLB) 21 Firewall Load Balancing (FWLB) and VPN Load Balancing 21 Global Server Load Balancing 22 Application and Content Networking System 22 Content Edge Delivery 23 Content Distribution and Routing 24 Content Network Partnership Program 25 Content Management 25 Content Distribution 26 Content Providers 26 E-Learning Applications 26 Content Filtering and Scanning 26 Summary 27 Review Questions 27 Recommended Reading 27 Part II Networking Fundamentals 29 Chapter 2 Exploring the Network Layers 31 Ethernet Physical and Data Link Layers 32 Physical Layer 32 Ethernet Mechanical Properties The Media 32 Ethernet Electrical Properties The Signaling 37 Data Link Layer 42 Internet Protocol 45 Address Resolution Protocol 48
Xi Internet Control Message Protocol 50 Layer 3 Connectivity Determination 50 Unavailable Port Errors 51 Announcement of New Default Routers 51 Internet Group Management Protocol and Protocol Independent Multicast 51 Transport Layer 52 Transmission Control Protocol 52 TCP Three-Way Handshake 54 TCP Sliding Window 57 TCP Slow Start 60 TCP Congestion Avoidance 61 TCP Fast Retransmit 62 TCP Fast Recovery 63 TCP Maximum Segment Size 64 TCP over Satellite 64 TCP Variable Summary 65 User Datagram Protocol 66 Putting It All Together with a Detailed Network Trace 67 Summary 69 Review Questions 69 Recommended Reading 70 Chapter 3 Introducing Switching, Routing, and Address Translation 73 Exploring Ethernet Frame Switching 73 Configuring Virtual LANs 76 Configuring VLAN Trunking 76 Exploring MAC Learning with Multiple VLANs 77 VLAN Trunking Protocol 79 Understanding IP Routing 81 Configuring Static Routing 82 Understanding Dynamic Routing 84 Packet Switching 87 Process Switching Path 88 Fast Switching Path 89 Cisco Express Forwarding 91 Transparent Bridging 94 Exploring Network Address Translation 95 Source Network Address Translation 95 Static Network Address Translation 96 Dynamic NAT 97 Port Address Translation (PAT) 98 Destination Translation 99 Summary 100
xii Review Questions 101 Recommended Reading 101 Chapter 4 Exploring Security Technologies and Network Infrastructure Designs 103 Filtering Packets with Access Control Lists 103 Application Layer Inspection 106 Designing Enterprise Campuses 108 Designing Enterprise Edge Networks 111 Designing Headquarters with Remote Office Networks 114 Employing Internet Content Delivery Networks 116 Summary 117 Review Questions 117 Recommended Reading 117 Part III Intelligent Network Services for Content Delivery 119 Chapter 5 IP Multicast Content Delivery 121 Introducing IP Multicast 121 Internet Group Management Protocol 124 Internet Group Management Protocol, Version 1 124 Internet Group Management Protocol, Version 2 126 Internet Group Management Protocol, Version 3 127 Internet Standard Multicast 129 Distribution Trees 129 Protocol Independent Multicast 130 PIM Dense Mode 132 PIM Sparse Mode 134 PIM Sparse-Dense Mode 138 Bidirectional PIM 139 Configuring Rendezvous Point and Multicast Group Selection 141 Auto-RP 142 Bootstrap Routers 144 Configuring Inter-Domain Multicast with Multicast Source Discovery Protocol 146 AnycastRP 148 Layer 2 Multicast Protocols 149 Cisco Group Management Protocol (CGMP) 149 IGMP Snooping 150 Router-Port Group Management Protocol 151 Source Specific Multicast (SSM) 151 Ensuring Multicast Delivery With Pragmatic General Multicast 153 Summary 156 Review Questions 156 Recommended Reading 157
xiii Chapter 6 Ensuring Content Delivery with Quality of Service 159 Classification and Marking 160 Marking Packets at Layer 3 161 Marking a Packet's IP Precedence Value 161 Marking a Packet's IP Differentiated Services Code Field 162 IP QoS Group Value 165 Marking Frames, Cells, and Trunks at Layer 2 165 Network-Based Application Recognition 166 Congestion Management 171 Understanding Layer 3 Router Packet Queuing 171 Configuring Priority Queuing 172 Configuring Custom Queuing 173 Configuring Weighted Fair Queuing and IP RTP Priority Queuing 174 Configuring Class-Based WFQ with Low Latency 176 Understanding Layer 2 Switch Ethernet Frame QoS 178 Congestion Avoidance 180 Configuring Weighted Random Early Detection 180 Understanding Policing and Shaping 183 Configuring Generic Traffic Shaping 186 Configuring Class-Based Traffic Shaping 187 Configuring Committed Access Rate (CAR) 187 Configuring Class-Based Policing 188 Configuring Two-Rate Policing 189 QoS Policy Signaling 189 BGP QoS Policy Propagation 189 Resource Reservation Protocol (RSVP) 190 Summary 194 Review Questions 195 Recommended Reading 195 Part IV Applications for Serving Content, at the Network Edge 197 Chapter 7 Presenting and Transforming Content 199 Introducing Markup Languages 199 Hypertext Markup Language 203 Extensible Markup Language 205 Extensible Hypertext Markup Language 207 Wireless Application Protocol Markup Languages 208 Transforming and Formatting Content 210 Transforming XML to XHMTUHMTL 210 Using Cascading Style Sheets 213 Transforming XML to XSL-FO 216 Summary 220 Review Questions 220 Recommended Reading 221
xiv Chapter 8 Exploring the Application Layer 223 HTTP 224 HTTP 1.0 Versus HTTP 1.1 224 HTTP Transactions 225 HTTP Connection Persistence and Pipelining 227 Maintaining Client-Side State with HTTP Cookies 230 HTTP Authentication 231 HTTP Caching Controls 233 Implicit Cache Controls 233 Explicit Controls 235 Public Key Infrastructure 236 Secret Key Cryptography 236 Public-Key Cryptography 237 Identity Theft Prevention Using Certificates 240 Secure Sockets Layer 246 File Transfer Protocol 250 Summary 254 Review Questions 254 Recommended Reading 254 Chapter 9 Introducing Streaming Media 257 Streaming Files and Content Playback 257 Creating Streaming On-Demand Container Files 261 Describing Streaming On-Demand Content with Meta-Files 264 Streaming with Microsoft WMT, Real Networks, and Apple QuickTime 265 Streaming Motion Picture Experts Group 266 Delivering Streaming Media 267 Transferring Streaming Media with the Real-Time Transport Protocol 268 Real-time Data Control with Real Time Streaming Protocol 270 Fast-Forwarding and Rewinding a Stream with RTSP 275 Using Quality of Service and IP Multicast with Streaming Media 275 Summary 276 Review Questions 277 Recommended Reading 277 Part V Application Layer Services for Content, within the Network 279 Chapter 10 Exploring Server Load Balancing 281 Exploring Your Server Load-Balancing Devices 287 Content Services Switch 289 CSS Packet Flow 290 CSS Models 292 Content Switching Module 295
XV Content Switch Operational Modes 298 Bridge-Mode Content Switching 300 Router Mode Content Switching 307 Load-Distribution Algorithms 311 Round Robin 311 Least Connections 313 Configuring Server Load 315 Calculating Relative Load 315 Calculating Absolute Load 317 Hash Distribution 319 Layer 5-7 Load Balancing 320 Equal-Cost Multi-Path Router Load Balancing 326 Health Checking 327 Out-of-Band Health Checking 327 ln-band Health Checking 330 Session Persistence 332 Hash Load Balancing 332 IP Address Stickiness 332 HTTP Cookies 334 URL Sticky Strings 338 SSL Sticky 338 SIP Caller ID and MSISDN Number Sticky 340 Permanent Session Information Storage 340 Content Switch High Availability 340 CSS High Availability 341 CSM High Availability 347 Summary 352 Review Questions 352 Recommended Reading 352 Chapter 11 Switching Secured Content 355 SSL Termination 355 Configuring Your CSS for SSL Termination 358 Creating and Importing Keys and Certificates on the CSS 358 Terminating SSL on the CSS 360 Configuring URL and Header Rewrite on the CSS 362 Configuring Your Content Services Module with SSL 363 Creating and Importing Keys and Certificates on the CSM 363 Terminating SSL on the CSM-S 366 Configuring URL and Header Rewrite on the CSM 370
xvi Firewall Load Balancing 371 CSS Firewall Load Balancing 371 CSM Firewall Load Balancing 374 Configuring Reverse Stickiness 378 Configuring Single-CSM FWLB 379 VPN Load Balancing on the CSM 382 Preventing Connection Table Flooding using SYN-Cookies 384 Summary 385 Review Questions 385 Recommended Reading 385 Chapter 12 Exploring Global Server Load Balancing 387 Domain Name Service Operation 387 Introducing DNS Resource Records 389 Iterative DNS 390 Recursive DNS 392 BGP-Anycast and DNS Round-Robin 394 Exploring Distributed Director Technologies 394 Director Response Protocol and Boomerang Protocol 398 HTTP Redirection 402 A Robust Distributed Director Configuration 404 Exploring CSS Global Server Load Balancing 405 CSS Multisite Load Distribution 405 CSS Proximity-Based Load Balancing 408 Multitiered Proximity 411 Configuring Content Routing Agents 411 Exploring CSM Global Server Load Balancing 411 GSLB Stickiness 415 Summary 419 Review Questions 419 Recommended Reading 419 Part VI The Application and Content Networking System: Content Caching, Streaming, Routing, and Distribution 421 Chapter 13 Delivering Cached and Streaming Media 423 Redirecting Application Requests 423 Introducing Web Cache Control Protocol 423 < Redirecting Traffic at Layer 2 and Layer 3 with Web Cache Control Protocol 426 Input Redirection Vs. Output Redirection 427 WCCP Load Distribution Using Hash Buckets 428 Recovering from a CE Failure 429 Adding a New CE 430 WCCP Hot Spot Handling 431 WCCP CE Load Shedding 432
xvii WCCP Load Distribution Using Mask Assignment 432 Layer 4-7 Content Switch Redirection 434 Content Switch Load Distribution 435 Adding and Removing CEs When Using CSS Redirection 436 Request Redirection Topologies 437 Proxy Caching 437 Transparent Caching 440 Reverse Transparent Caching 441 Ensuring Content Freshness 445 Preloading Content 445 Transparently Delivering Authenticated Content 446 Enabling Transparent Value-Added Services on Your CEs 447 Content Authentication and Authorization 448 SSL Caching and Tunneling 449 Internet Content Adaptation Protocol 450 URL Filtering 452 Adjusting TCP/IP Parameter Values 453 Delivering Streaming Media 454 Streaming Video-on-Demand 456 Splitting Live and Prerecorded Broadcasts 457 Streaming Windows Media Technology 459 Configuring Windows Media Video on Demand 459 Configuring the CE Internal WMS Server for Live and Scheduled Rebroadcast Presentations 460 Streaming Real Media 464 RealProxy Video-on-Demand Caching 467 RealProxy Pull-Splitting 467 Summary 469 Review Questions 470 Recommended Reading 470 Chapter 14 Distributing and Routing Managed Content 473 E-learning and Corporate Communications 473 Software and File Distribution 474 Introducing Content Distribution and Routing 475 Initializing and Registering Your ACNS Network Devices 477 Setting Up Your ACNS Network for Acquisition and Pre-Positioning 479 Creating Location Trees 480 Configuring Content Channels 482 Acquiring Content to Pre-Position 485 Configuring Acquisition Using Manifest Files 486 Configuring Acquisition Using the CDM GUI 487
xviii Configuring Content Pre-Positioning 488 Multicast-Push Distribution Trees 488 Unicast-Pull Distribution Trees 489 Content Request Routing 491 Simplified Hybrid Routing 491 Dynamic Proxy Auto-Configuration 494 Configuring Streaming Media 497 Streaming Prepositioned Video On-Demand Content 498 Creating Scheduled Live and Rebroadcast Programs in ACNS 500 Summary 503 Review Questions 503 Recommended Reading 503 Appendix A Answers to Review Questions 505 Index 522