Cisco 6 Routers. Andrew Hamilton John Mistichelli with Bryant G. Tow O SYBEX San Francisco Paris Düsseldorf Soest London
Introduction xviii Part 1 Up and Running 1 Chapter 1 A Brief Review of the OSI Model 3 The Upper Layers 4 Layer 7: The Application Layer 4 Layer 6: The Presentation Layer 5 Layer 5: The Session Layer 7 The Lower Layers 8 Layer 4: The Transport Layer 8 Connection-Oriented versus Non-Connection-Oriented Protocols 10 Layer 3: The Network Layer 18 Layer 2: The Data Link Layer 20 Layer 1: The Physical Layer 23 Switching versus Routing 25 Chapter 2 LAN and WAN Technologies 29 Local Area Network (LAN) Technologies 30 Ethernet/IEEE 802.3 30 Fast Ethernet 41 Fast EtherChannel 46 Token Ring 46 Fiber Distributed Data Interface (FDDI) 52 Gigabit Ethernet 55 Wide Area Network (WAN) Technologies 55 Leased Lines 55 Circuit-Switched Circuits 55 Packet-Switched Circuits 56 High-Level Data Link Control (HDLC) 56 Point-to-Point Protocol (PPP) 57
x Integrated Services Digital Network (ISDN) 60 Frame Relay 61 Chapter 3 Routed Protocols 63 The Internet Suite of Protocols 63 Transmission Control Protocol (TCP) 64 User Datagram Protocol 67 Internet Protocol 67 The IP Address. 69 Configuring IP 78 Name Resolution 78 Network Address Translation 79 EasylP 82 Internet Packet exchange (IPX) 82 IPX Packet Structure 83 IPX Addressing Structure 84 Configuring IPX 85 AppleTalk 86 Configuring AppleTalk 87 Chapter 4 Network Design 89 Scalability 90 The Core Layer 91 The Distribution Layer 93 The Access Layer 93 Manageability 94 Out-of-Band Management 94 Connectivity 95 Route Summarization 95 Route Redistribution 98 Tunneling 101 Sizing 103 Communication Lines 103 Routers 105 24seven Design 112
xi Chapter 5 The Cisco Router Product Line 121 High-End Routers 121 Cisco 12000 GSRSeries 122 Cisco 7000 Series 122 Small/Medium Business Solutions 129 800/900 ISDN Routers 129 1400 DSL Routers 130 1600 Modular Data Routers 131 1700 Modular Access Routers 131 2500 Fixed Configuration Data Routers 133 2600 Modular Voice/Data Routers..134 3600 Modular Voice/Data Routers 135 MC3800 Multiservice Router 136 4000 Modular Data Router 137 When to Use Which Model 139 Part 2 Routing Protocols 143 Chapter 6 Distance-Vector Routing Protocols 145 Autonomous System 145 Classfull versus Classless 146 Administrative Distance 148 Routing Information Protocol (RIP) 148 Configuring RIP 149 RIPv2 152 Interior Gateway Routing Protocol (IGRP) 155 Split Horizon 162 Chapter 7 Link-State Routing Protocols 169 Open Shortest Path First (OSPF) 170 OSPF Operation 170 Maintaining Adjacencies. 171 OSPF Areas 173 Configuring OSPF 174 Verifying OSPF Operation 181
xii NetWare Link Services Protocol (NLSP) 183 Configuring NLSP 184 Verifying NLSP Operation 186 Integrated Intermediate System to Intermediate System (IS-IS)...187 Configuring IS-IS 187 Chapter 8 EIGRP: A Hybrid Routing Protocol 191 Enhanced IGRP (EIGRP) 191 EIGRP Operation: The DUAL Algorithm 193 Configuring EIGRP for IP 195 Verifying IP EIGRP 197 EIGRP for IPX 204 EIGRP for AppleTalk 208 Part 3 Router Configuration 213 Chapter 9 Configuring a Router: An Introduction 215 The Boot Sequence 216 Your Router and Its Many Modes 217 ROM Monitor Mode 218 RxbootMode 218 User Exec Mode 218 Privileged Exec Mode 219 Config Mode 220 Context-Sensitive Help in the Modes 221 Tools for Configuring Your Router 223 Configuring a Router Using the Setup Script 223 Configuring a Router Using TFTP 223 Config Maker 225 Command Line Interface 225 Boot System Commands 226 Passwords 227 Configuration and the IOS 231
xiii Backing Up the IOS 231 Updating the IOS 232 Chapter 10 Configuring and Troubleshooting TCP/IP 241 Drawing Out the Logical Addressing of the Environment 241 If You Must Draw by Hand 242 Software Network Drawing Solutions 242 Cheater Chart 244 Setting Up Your Routers 245 Verify That Everything Is Physically Connected First 245 Interface Descriptions 246 Point-to-Point Connectivity 248 Confirming Your Environment Is Working Properly 248 Useful Tools for Testing IP Connectivity 248 Useful Debug Commands for IP 255 Debug IP Packet 257 Changing Your IP Addressing Scheme 260 Deciding on IP Addresses 260 Secondary IP Addresses 261 Setting Up a Simple Statically Routed Environment 262 Why Use Static Routing? 262 Advanced Static Routing for Route Backup 264 DHCP in a Routed Environment 266 Chapter 11 Internet Packet Exchange (IPX) 271 IPXRIP 271 IPX SAP 272 Get Nearest Server (GNS) 273 Configuring IPX 274 Filtering SAPs 278 Creating a SAP Filter 278 Applying a SAP Filter 279 Verifying IPX Operation 280
xiv The show ipx route Command 280 The show ipx interface Command 281 The show ipx traffic Command 283 The show ipx Servers Command 284 The show ipx access-list Command 285 Other show ipx Command 286 The ping ipx Command 286 The trace ipx Command 287 The debug ipx Commands 288 Chapter 12 AppleTalk 295 Configuring AppleTalk 295 Required AppleTalk Configuration Activities 296 Optional Configuration Activities 297 Debugging AppleTalk 312 Chapter 13 Configuring ISDN and Dial-on-Demand Routing (DDR)... 317 ISDN Components 317 ISDN Reference Points 318 Basic Rate Interface (BRI) 319 Configuring BRI 319 Primary Rate Interface (PRI) 320 Configuring PRI 321 Dial-on-Demand Routing (DDR) 321 Configuring DDR 321 Optional DDR Commands 323 Dialer Profiles 326 Verifying DDR 329 Snapshot Routing 333 Configuring Snapshot Routing 333 Dial Backup 335 Configuring Dial Backup 335
xv Part 4 Optimization and Maintenance 339 Chapter 14 Traffic Prioritization and Queuing 341 Traffic Prioritization 342 Types of Queuing 344 Weighted Fair Queuing 345 Priority Queuing 347 Custom Queuing 351 Another Traffic Control Mechanism: Weighted Random Early Detection (WRED) 356 Traffic Prioritization for Specific Protocols 360 Frame Relay Traffic Shaping 360 IPX Traffic Considerations 365 Chapter 15 Securing the Environment 383 Making Your Router a Bastion Host 384 Console Port 384 Telnet Access 385 TACACS 387 Other Router Access Methods 390 Access Lists 400 Standard Access Lists 402 Extended Access Lists 405 Creating Security: A Stance with Access Lists 414 Virtual Private Networks 426 VPN Configuration 429 Address Translation 440 Chapter 16 Router Management 451 Syslog 452 Buffered Logging 452 Syslog Servers 455 Getting Router Health Information via the Command Line....457 SNMP and Other Network Management Protocols 463 Looking at SNMP 464
xvi Management Systems 469 HP OpenView Network Node Manager 471 CiscoWorks 473 CiscoWorks 2000 CWSI Campus 475 RMON 480 Chapter 17 Troubleshooting Tools 485 Troubleshooting Philosophies 486 Basic Troubleshooting Tools..488 Ping 488 Traceroute 492 The Address Resolution Protocol (ARP) 496 Cisco Discovery Protocol (CDP) 497 Advanced Tools 499 Debug Commands 499 Protocol Analyzers 502 Troubleshooting Specific Elements of the Network 505 Troubleshooting the Physical Layer 505 Troubleshooting the Telecommunication Line 510 CSU/DSUs and Serial Lines 511 Frame Relay 513 Chapter 18 Disaster Recovery 523 Planning for the Worst 523 Redundancy in Hardware 525 Power Supplies 525 7000 Series Redundancy 525 12000 Series Redundant Gigabit Route Processor 525 Backing Up the Router Image and Configuration 526 Backing Up the Router Image 526 Backing Up the Router Configuration 528 Swapping Out a Router 530 Replacing the Router Image 530
xvii Catastrophic Software Failure 531 Replacing Router Configuration 533 Contacting Cisco Technical Assistance Center 537 Cisco Web Support 537 E-Mail Cisco TAC 538 Telephone Support 538 How TAC Works 540 Chapter 19 Advanced Topics 547 Hot Standby Router Protocol (HSRP) 547 WhatlsHSRP? 547 Why Do I Need HSRP? 548 How Does HSRP Work? 548 HSRPIssues 553 ICMP Router Discovery Protocol (IRDP) 556 IRDP Functionality 556 IRDP Application 557 Advanced BGP Topics 559 BGP Communities 559 The Firewall Feature Set 564 Versions and Compatibility 564 Firewall Features 565 Intrusion Detection System (IDS) 574 Appendices 579 Appendix A Password Recovery/Resetting 581 2000, 2500, 3000, 4000, 7000 and AGS Series Routers 581 1003, 4500, 3600, and 2600 Series Routers 583 Appendix B ICMP Types and Codes 585 Appendix C Common Cable Pinouts 589 Index 593