Schweitzer Fachinformationen
Wenn es um professionelles Wissen geht, ist Schweitzer Fachinformationen wegweisend. Kunden aus Recht und Beratung sowie Unternehmen, öffentliche Verwaltungen und Bibliotheken erhalten komplette Lösungen zum Beschaffen, Verwalten und Nutzen von digitalen und gedruckten Medien.
Network Maintenance and Troubleshooting Guide
Field-Tested Solutions for Everyday Problems, Second Edition
Neal Allen
The 100% practical, real-world guide to anticipating, finding, and solving network problems-fast!
Real-life networks don't always behave "by the book." Troubleshooting them requires practical intuition that normally comes only with experience. In this book, Fluke Networks' Neal Allen brings together all that hard-won, hands-on insight: everything you need to discover what's really happening in your network, so you can anticipate and fix problems before users even notice them.
Writing for network technicians and administrators at all levels, Allen presents an approach to troubleshooting that has been proven in networks of all kinds, no matter how complex. He introduces indispensable triage and troubleshooting techniques for everything from copper and fiber cabling to IPv6, and presents unparalleled guidance on identifying and resolving problems at the MAC Layer. He illustrates his advice with diagrams, tables, and screen captures from Fluke Networks' market-leading instruments. Throughout this book, Allen also offers practical summaries of each of today's core networking technologies, making it an ideal complement to any network certification study guide.
Coverage includes
Road tested by thousands of Fluke Networks customers, this book's first edition became the best-kept secret resource for sysadmins, netadmins, and support technicians fortunate enough to discover it. Now, Allen has thoroughly updated his classic for today's networks. If you're responsible for maintaining one of those networks, you'll find this new Second Edition even more indispensable.
Neal Allen is a senior staff engineer in the Fluke Networks' Technical Assistance Center (TAC) focusing on escalated problems. He has been involved in designing, installing, and troubleshooting networks for nearly 20 years. Allen has served on Interop's trade show Network Operations Center (NOC) team since 1993, troubleshooting show-floor problems at the Las Vegas and Atlanta Interop trade shows, and helped support and troubleshoot the network for the 1996 Atlanta Olympic Games. His responsibilities currently include product feature specification and beta testing, remote and onsite problem solving, and providing training and sales support worldwide.
Cover design by Louisa Adair
Cover photography from Image Source / Getty Images
Introduction
Chapter 1: Using the OSI Model
Quick Tour of the OSI Model
Seven Layers of the OSI Model
Layer 7: Application Layer
Layer 6: Presentation Layer
Layer 5: Session Layer
Layer 4: Transport Layer
Layer 3: Network Layer
Layer 2: Data Link Layer
Layer 1: Physical Layer
Networking Devices and the OSI Model
Repeaters
Bridges
Routers
Switches
Switch Forwarding Techniques
Common Networking Tools
Network Management Tools
Protocol Analyzers
Handheld Network Analyzers
Cable Testers
Flow Protocols
Summary
Chapter Review Questions
Chapter 2: Copper Media
Standards
Basic Cable Uses
Test Parameters
Basic Tests and Parameters Required for In-Channel Testing
Basic Frequency-Based Test Parameters Related to In-Channel Testing
Advanced Frequency-Based Test Parameters Related to In-Channel and External Testing
Other Commonly Referenced Test Parameters
Test Configurations
What Should Be Tested?
Grounding and Shielding Cable
Chapter 3: Fiber Optic Media
Safety
Light
Glass
Fiber Optic Cable Design
Fiber Cable Construction
Cable Construction
Connector Types
Field Testing Parameters
Light Behavior
Dispersion
Modal Bandwidth
Critical Angle
Bending Fiber
Graded Index
Light Sources
Launch Conditions
Mandrels
Mode Conditioning
Absorption
Fresnel Reflections
Fiber Termination Polish
Fiber Alignment Errors and Manufacturing Flaws
Testing Practices and Tools
Test Methods
Tools
Levels of Testing
Tier 1
Tier 2
Precautions for Measurement and Testing
Chapter 4: Media Access Control Layer
Ethernet and the OSI Model
Frame Structure
Bits to Bytes
Bytes to Field Groupings
Basic Ethernet Frame Fields
Theory of Operation
Interpacket Spacing
Retransmission
Error Handling
Duplex
Frame Bursting
Auto-Negotiation
Power over Ethernet (PoE)
Ethernet Implementation Details
10 Mbps Versions of Ethernet
100Mbps Versions of Ethernet
1000Mbps Versions of Ethernet
10Gbps Versions of Ethernet
10GBASE-T Receive Process
Ethernet for Subscriber Access Networks
Chapter 5: Data Link Layer
Bridge Forwarding Table
Effect of Forwarding
Priority
Spanning Tree Protocol
VLANs
MAC Control Sublayer
Slow Protocols
Link Aggregation Sublayer
Operations, Administration, and Maintenance (OAM) Sublayer
Logical Link Control Sublayer
802.2 LLC
802.2 LLC Field Definitions
802 SNAP
802 SNAP Field Definitions
Novell Raw
Chapter 6: Network Layer
OSI Model Implications: Effect of Forwarding
Internet Protocol (IP)
IPv4 Addressing
Internet Control Message Protocol (ICMP)
IPv6 Addressing
ICMPv6
Chapter 7: Transport Layer
TCP and UDP Ports
Transmission Control Protocol (TCP)
TCP Segments and Maximum Segment Size (MSS)
TCP Sockets and Connections
Opening and Closing Connections
Sequence and Acknowledgment Numbers
Selective Acknowledgment (SACK)
Window Size, Window Scaling, and Sliding Window
Congestion Control
TCP Segment Structure
User Datagram Protocol (UDP)
User Datagram Protocol (UDP) Datagram Structure
Chapter 8: Preventing Problems
Strategy for Network Maintenance
1. Management Involvement in Network Decision Making
2. Preparation and Planning
3. Problem Prevention
4. Early Problem Detection
5. Quick Problem Isolation and Resolution
6. Investing More in Tools and Training Rather Than Additional Staff to Accommodate Network Growth
7. Quality Improvement Approach to Network Management and Maintenance
Documentation
Methodology
Discovery and Baselining
Design Assistance
Validation
Create a Server Log and Software Library
Create a Network Diagram
Cable Plant Documentation
Develop a Baseline
Traffic Monitoring
Proactive Activity and Preparedness
Monitoring the Physical and MAC Layers
Monitoring the Network Layer
Monitoring the Transport Layer
Application Monitoring
Chapter 9: Troubleshooting
Best Method
Process
Eight Key Steps to Successful Troubleshooting
Step 1. Identify the Exact Issue
Step 3. Localize and Isolate the Cause
Step 4. Formulate a Plan for Solving the Problem
Step 5. Implement the Plan
Step 6. Test to Verify That the Problem Has Been Resolved
Step 7. Document the Problem and Solution
Step 8. Provide Feedback to the User
A Place to Start
Chapter 10: Troubleshooting Media
Troubleshooting Copper Media
General Testing and Installation Issues
Troubleshooting Fiber Optic Media
Chapter 11: Network Troubleshooting
Protocol Analysis
Network Management
Advanced Analysis Products
Troubleshooting Generalized User Complaints
Problem: Can't Connect
Problem: Connections That Drop
Problem: Slow or Poor Performance
General Troubleshooting Advice
Specific Error Types
Some Simple Guidelines
Specific Test Suggestions
Appendix A: Copper Test Failure Cause Tables
Wiremap
Length
Propagation Delay or Delay Skew
Insertion Loss (Attenuation)
NEXT and PSNEXT
Return Loss
ACRF and PSACRF (ELFEXT and PSELFEXT)
Resistance
Characteristic Impedance
Impulse Noise
Alien Crosstalk Mitigation
Appendix B: Waveform Decoding Exercise
Module 1: Counting Systems and Encoding Methods
Counting Systems
OSI Seven-Layer Model
Signaling and Encoding Methods
Module 2: Decoding a Waveform into Ethernet
10Mbps Transmission Process
Decoding the Waveform
Module 3: Using Standards Documents and RFCs
Standards and RFCs
Module 4: Using a Protocol Analyzer
OptiView Protocol Expert in Five Buttons
Protocol Expert Lab
Appendix C: Auto-Negotiation
FLP Field Definitions
Base Page
Message Pages
Unformatted Pages
Extensions to Auto-Negotiation for 1000BASE-X
Extensions to Auto-Negotiation for 10GBASE-T
Appendix D: Discovering Device Behavior
At What Layer Does This Device Operate?
Test #1: Basic Functionality
Test #2: The Gray Area
Test #3: Find Any Configured VLANs
How to Use the Test Results
Collision Domain
Broadcast Domain
Different Network
Appendix E: Techniques for Troubleshooting Switches
What Problems Are Encountered in Switched Environments?
How Do You Find Which Port or Switch Has a Problem?
Techniques for Troubleshooting a Switch
Method 1: Access the Switch Console
Method 2: Connect to an Unused Port
Method 3: Configure a Mirror or Span Port
Method 4: Connect to a Tagged or Trunk Port
Method 5: Insert a Hub into the Link
Method 6: Place the Tester in Series
Method 7: Place a Tap Inline on a Link
Method 8: Use SNMP-Based Network Management
Method 9: Have the Switch Send Flow Technology Summaries
Method 10: Set Up a Syslog Server
Method 11: Use the Server (Host) Resources
Method 12: Use a Combination of Methods
Troubleshooting Methods: Conclusion
Appendix F: Simple Network Management Protocol
SNMP Operation
SNMPv1
SNMPv2
SNMPv3
SNMP Use
Appendix G: Troubleshooting with a Protocol Analyzer
Understanding a Web Page Connection
DNS Query
ARP Query
TCP Connection
Data Transfer
Closing the Connection
DNS Failure
Protocol Analyzers and Protocol Knowledge
Appendix H: Network Diagnostic Products Used in This Book
What Tool to Start With?
Network Operations
Network Engineering
Network Technicians
Network/PC Support Help Desk
Media Test
DTX 1800 Cable Analyzer
OptiFiber Certifying OTDR
AnalyzeAir Wi-Fi Spectrum Analyzer
Network Analysis: Hybrid Handhelds
OptiView
EtherScope
NetTool
LinkRunner
Capture
Built-in Features
Alarms and Triggers
Data Storage and Reporting
Flow Protocols Analysis
Visual Performance Manager
Visual UpTime Select
NetFlow Tracker
Application Performance
Appendix I: Answers to Chapter Review Questions
9780321647412 TOC 9/29/2009
Dateiformat: PDFKopierschutz: Wasserzeichen-DRM (Digital Rights Management)
Systemvoraussetzungen:
Das Dateiformat PDF zeigt auf jeder Hardware eine Buchseite stets identisch an. Daher ist eine PDF auch für ein komplexes Layout geeignet, wie es bei Lehr- und Fachbüchern verwendet wird (Bilder, Tabellen, Spalten, Fußnoten). Bei kleinen Displays von E-Readern oder Smartphones sind PDF leider eher nervig, weil zu viel Scrollen notwendig ist. Mit Wasserzeichen-DRM wird hier ein „weicher” Kopierschutz verwendet. Daher ist technisch zwar alles möglich – sogar eine unzulässige Weitergabe. Aber an sichtbaren und unsichtbaren Stellen wird der Käufer des E-Books als Wasserzeichen hinterlegt, sodass im Falle eines Missbrauchs die Spur zurückverfolgt werden kann.
Weitere Informationen finden Sie in unserer E-Book Hilfe.
