Hjem

Chapter 1 Troubleshooting Methods 1 Troubleshooting Principles 1 Structured Troubleshooting Approaches 4 The Top-Down Troubleshooting Approach 6 The Bottom-Up Troubleshooting Approach 7 The Divide-and-Conquer Troubleshooting Approach 8 The Follow-the-Path Troubleshooting Approach 9 The Compare-Configurations Troubleshooting Approach 10 The Swap-Components Troubleshooting Approach 11 Troubleshooting Example Using Six Different Approaches 12 Summary 13 Review Questions 14
Chapter 2 Structured Troubleshooting 15 Troubleshooting Method and Procedure 16 Defining the Problem 17 Gathering Information 18 Analyzing the Information 20 Eliminating Potential Causes 21 Proposing a Hypothesis (Likely Cause of the Problem) 21 Testing and Verifying Validity of the Proposed Hypothesis 23 Solving the Problem and Documenting the Work 24 Troubleshooting Example Based on the Structured Method and Procedures 25 Summary 26 Review Questions 27
Chapter 3 Network Maintenance Tasks and Best Practices 29 Structured Network Maintenance 29 Network Maintenance Processes and Procedures 31 Common Maintenance Tasks 32 Network Maintenance Planning 33 Scheduling Maintenance 33 Formalizing Change-Control Procedures 34 Establishing Network Documentation Procedures 34 Establishing Effective Communication 35 Defining Templates/Procedures/Conventions (Standardization) 36 Planning for Disaster Recovery 36 Network Maintenance Services and Tools 37 Network Time Services 39 Logging Services 40 Performing Backup and Restore 42 Integrating Troubleshooting into the Network Maintenance Process 47 Network Documentation and Baseline 48 Communication 50 Change Control 53 Summary 54 Review Questions 57
Chapter 4 Basic Switching and Routing Process and Effective IOS Troubleshooting Commands 61 Basic Layer 2 Switching Process 61 Ethernet Frame Forwarding (Layer 2 Data Plane) 62 Layer 2 Switching Verification 67 Basic Layer 3 Routing Process 69 IP Packet Forwarding (Layer 3 Data Plane) 70 Using IOS Commands to Verify IP Packet Forwarding 73 Selective Information Gathering Using IOS show Commands, debug Commands, Ping, and Telnet 76 Filtering and Redirecting show Command''s Output 76 Testing Network Connectivity Using Ping and Telnet 81 Collecting Real-Time Information Using Cisco IOS debug Commands 85 Diagnosing Hardware Issues Using Cisco IOS Commands 86 Checking CPU Utilization 87 Checking Memory Utilization 88 Checking Interfaces 89 Summary 92 Review Questions 94
Chapter 5 Using Specialized Maintenance and Troubleshooting Tools 99 Categories of Troubleshooting Tools 100 Traffic-Capturing Features and Tools 101 SPAN 102 RSPAN 103 Information Gathering with SNMP 105 Information Gathering with NetFlow 107 Network Event Notification 109 Summary 113 Review Questions 114
Chapter 6 Troubleshooting Case Study: SECHNIK Networking 117 SECHNIK Networking Trouble Ticket 1 118 Troubleshooting PC1''s Connectivity Problem 118 Gathering Information 119 Analyzing Information, Eliminating Causes, and Gathering Further Information 119 Proposing Hypotheses 121 Testing the Hypotheses and Solving the Problem 121 Troubleshooting Ethernet Trunks 122 Troubleshooting PC2''s Connectivity Problem 123 Gathering Information 124 Proposing a Hypothesis, Testing the Hypothesis, and Solving the Problem 126 Troubleshooting NAT 127 Troubleshooting PC3''s Connectivity Problem 128 Gathering Information 129 Eliminating Possibilities, Proposing a Hypothesis, and Testing the Hypothesis 129 Troubleshooting Network Device Interfaces 130 Troubleshooting PC4''s IPv6 Connectivity Problem 131 Gathering Information 131 Eliminating Possibilities, Proposing a Hypothesis, and Testing the Hypothesis 132 Troubleshooting IPv6 Address Assignment on Clients 133 SECHNIK Networking Trouble Ticket 2 134 Troubleshooting PC1''s Internet Connectivity Problem 134 Gathering Information 135 Proposing a Hypothesis, Testing the Hypothesis, and Solving the Problem 137 Troubleshooting Network Layer Connectivity 138 Troubleshooting PC2''s SSH Connectivity Problem 141 Verifying and Defining the Problem 141 Gathering Information 142 Proposing a Hypothesis and Testing the Hypothesis 143 TCP Three-Way Handshake 145 Troubleshooting PC4''s DHCP Address Problem 146 Verifying and Defining the Problem 146 Gathering Information 147 Proposing a Hypothesis, Testing a Hypothesis, and Solving the Problem 148 Troubleshooting Error-Disabled Ports 151 SECHNIK Networking Trouble Ticket 3 152 Troubleshooting PC1 and PC2''s Internet Connectivity Issues 153 Verifying and Defining the Problem 153 Gathering Information 153 Proposing a Hypothesis and Testing the Hypothesis 157 Solving the Problem 159 Troubleshooting DHCP 160 The passive-interface Command 161 Troubleshooting PC3''s Internet Connectivity Issues 162 Verifying and Defining the Problem 162 Gathering Information 162 Proposing a Hypothesis and Testing the Hypothesis 164 Solving the Problem 165 IPv6 Review 166 Summary 166 Review Questions 169
Chapter 7 Troubleshooting Case Study: TINC Garbage Disposal 173 TINC Garbage Disposal Trouble Ticket 1 174 Troubleshooting Lack of Backup Internet Connectivity Through GW2 174 Information Gathering 176 Analyzing Information, Eliminating Possibilities, and Proposing a Hypothesis 178 Proposing a Hypothesis, Testing the Hypothesis, and Solving the Problem 178 Troubleshooting BGP Neighbor Relationships 181 Troubleshooting PC1''s Connectivity Problem 182 Gathering Information 182 Analyzing Information and Gathering Further Information 183 Proposing a Hypothesis, Testing the Hypothesis, and Solving the Problem 184 Troubleshooting Port Security 186 Troubleshooting PC2''s Connectivity Problem 187 Gathering Information 188 Eliminating Possibilities, Proposing a Hypothesis, and Testing the Hypothesis 190 Solving the Problem 191 Troubleshooting VLANs 192 TINC Garbage Disposal Trouble Ticket 2 193 Troubleshooting GW1''s OSPF Neighbor Relation Problem with Router R1 194 Verifying the Problem 194 Gathering Information 194 Analyzing Information, Eliminating Possibilities, and Proposing a Hypothesis 199 Testing the Hypothesis and Solving the Problem 199 Troubleshooting OSPF Adjacency 201 Troubleshooting Secure Shell Version 2 Access to Router R2 from PC4 202 Verifying the Problem 202 Gathering Information 203 Proposing a Hypothesis and Testing the Hypothesis 204 Solving the Problem 205 Troubleshooting SSH and Telnet 206 Troubleshooting Duplicate Address Problem Discovered Through R1 and R2''s Log Messages 207 Verifying the Problem 207 Gathering Information 207 Analyzing the Information and Proposing a Hypothesis 210 Testing the Hypothesis and Solving the Problem 210 Troubleshooting HSRP 211 TINC Garbage Disposal Trouble Ticket 3 212 Troubleshooting Sporadic Internet Connectivity Problem Experienced by Users of PC1 and PC2 212 Verifying and Defining the Problem 213 Gathering Information 213 Analyzing Information and Proposing a Hypothesis 215 Testing the Hypothesis and Solving the Problem 217 Troubleshooting Erroneous Routing Information 218 Troubleshooting Multiple Masters within a VRRP 220 Verifying and Defining the Problem 220 Gathering Information 221 Analyzing the Information and Proposing a Hypothesis 222 Testing the Hypothesis, and Solving the Problem 222 Troubleshooting VRRP 224 Troubleshooting EtherChannel Between ASW4 and ASW3 224 Verifying the Problem 224 Defining the Problem 225 Gathering Information 225 Proposing a Hypothesis and Testing the Hypothesis 227 Solving the Problem 228 Troubleshooting EtherChannel 229 TINC Garbage Disposal Trouble Ticket 4 231 Troubleshooting Inconsistent and Sporadic Internet Connectivity Problem Experienced By Users of PC1 and PC2 231 Verifying and Defining the Problem 232 Gathering Information 233 Analyzing Information and Proposing a Hypothesis 235 Testing the Hypotheses 235 Solving the Problem 239 Troubleshooting FHRPs 241 Troubleshooting Sporadic Loss of Connectivity on PC4 242 Verifying the Problem and Making a Troubleshooting Plan 242 Gathering Information 242 Analyzing the Information and Gathering Further Information 244 Proposing a Hypothesis and Testing the Hypothesis 245 Solving the Problem 246 The Cisco IOS DHCP Snooping Feature 248 Cisco Technical Assistance Center 248 Troubleshooting SSH Connection from PC4 to Router GW2 249 Verifying the Problem and Making a Troubleshooting Plan 249 Gathering Information 250 Proposing a Hypothesis and Testing the Hypothesis 251 Solving the Problem 252 Summary 252 Review Questions 255
Chapter 8 Troubleshooting Case Study: PILE Forensic Accounting 257 PILE Forensic Accounting Trouble Tic