Network Flow Analysis

by Michael W. Lucas

Overview

You know that servers have log files and performance measuring tools and that traditional network devices have LEDs that blink when a port does something. You may have tools that tell you how busy an interface is, but mostly a network device is a black box. Network Flow Analysis opens that black box, demonstrating how to use industry-standard software and your existing hardware to assess, analyze, and debug your network.

Unlike packet sniffers that require you to reproduce network problems in order to analyze them, flow analysis lets you turn back time as you analyze your network. You'll learn how to use open source software to build a flow-based network awareness system and how to use network analysis and auditing to address problems and improve network reliability. You'll also learn how to use a flow analysis system; collect flow records; view, filter, and report flows; present flow records graphically; and use flow records to proactively improve your network. Network Flow Analysis will show you how to:
–Identify network, server, router, and firewall problems before they become critical
–Find defective and misconfigured software
–Quickly find virus-spewing machines, even if they’re on a different continent
–Determine whether your problem stems from the network or a server
–Automatically graph the most useful data

And much more. Stop asking your users to reproduce problems. Network Flow Analysis gives you the tools and real-world examples you need to effectively analyze your network flow data. Now you can determine what the network problem is long before your customers report it, and you can make that silly phone stop ringing.

Product Details

ISBN-13:	9781593273002
Publisher:	No Starch Press
Publication date:	06/01/2010
Sold by:	Penguin Random House Publisher Services
Format:	eBook
Pages:	224
File size:	1 MB

About the Author

Michael W. Lucas is a network/security engineer with extensive experience working with high-availability systems. He is the author of the critically acclaimed Absolute BSD, Absolute OpenBSD, Cisco Routers for the Desperate, and PGP & GPG, all from No Starch Press.

Table of Contents

;
Dedication;
ACKNOWLEDGMENTS;
INTRODUCTION;
Network Administration and Network Management;
Network Management Tools;
Enough Griping: What's the Solution?;
Flow-Tools and Its Prerequisites;
Flows and This Book;
Chapter 1: FLOW FUNDAMENTALS;
1.1 What Is a Flow?;
1.2 Flow System Architecture;
1.3 The History of Network Flow;
1.4 Flows in the Real World;
1.5 Flow Export and Timeouts;
1.6 Packet-Sampled Flows;
Chapter 2: COLLECTORS AND SENSORS;
2.1 Collector Considerations;
2.2 Sensor Considerations;
2.3 Implementing the Collector;
2.4 Installing Flow-tools;
2.5 Running flow-capture;
2.6 How Many Collectors?;
2.7 Collector Log Files;
2.8 Collector Troubleshooting;
2.9 Configuring Hardware Flow Sensors;
2.10 Configuring Software Flow Sensors;
2.11 The Sensor: softflowd;
Chapter 3: VIEWING FLOWS;
3.1 Using flow-print;
3.2 Setting flow-print Formats with -f;
3.3 TCP Control Bits and Flow Records;
3.4 ICMP Types and Codes and Flow Records;
Chapter 4: FILTERING FLOWS;
4.1 Filter Fundamentals;
4.2 Useful Primitives;
4.3 Filter Match Statements;
4.4 Using Multiple Filters;
4.5 Logical Operators in Filter Definitions;
4.6 Filters and Variables;
Chapter 5: REPORTING AND FOLLOW-UP ANALYSIS;
5.1 Default Report;
5.2 Modifying the Default Report;
5.3 Analyzing Individual Flows from Reports;
5.4 Other Report Customizations;
5.5 Useful Report Types;
5.6 Customizing Reports;
Chapter 6: PERL, FLOWSCAN, AND CFLOW.PM;
6.1 Installing Cflow.pm;
6.2 flowdumper and Full Flow Information;
6.3 FlowScan and CUFlow;
6.4 FlowScan Prerequisites;
6.5 Installing FlowScan and CUFlow;
6.6 Flow Record Splitting and CUFlow;
6.7 Using Cflow.pm;
Chapter 7: FLOWVIEWER;
7.1 FlowTracker and FlowGrapher vs. CUFlow;
7.2 FlowViewer Security;
7.3 Installing FlowViewer;
7.4 Configuring FlowViewer;
7.5 Using FlowViewer;
7.6 FlowGrapher;
7.7 FlowTracker;
7.8 Interface Names and FlowViewer;
Chapter 8: AD HOC FLOW VISUALIZATION;
8.1 gnuplot 101;
8.2 Time-Series Example: Bandwidth;
8.3 Automating Graph Production;
8.4 Comparison Graphs;
Chapter 9: EDGES AND ANALYSIS;
9.1 NetFlow v9;
9.2 sFlow;
9.3 Problem Solving with Flow Data;
9.4 Afterword;
UPDATES;