TCP/IP essentials : a lab-based approach

278 Pages·2004·1.276 MB·English

by  Shivendra S Panwar, et al

TCP/IP Essentials
A Lab-Based Approach
Shivendra S. Panwar
DepartmentofElectricalandComputerEngineering,
PolytechnicUniversity,Brooklyn,NewYork
Shiwen Mao
TheBradleyDepartmentofElectricalandComputerEngineering,
VirginiaPolytechnicInstituteandStateUniversity
Blacksburg,Virginia
Jeong-dong Ryoo
ElectronicsandTelecommunicationsResearchUnit,
Daejeon,SouthKorea
Yihan Li
DepartmentofElectricalandComputerEngineering,
PolytechnicUniversity,
Brooklyn,NewYork
CAMBRIDGE UNIVERSITY PRESS
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© Cambridge University Press 2004
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without the written permission of Cambridge University Press.
First published in print format 2004
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ISBN-10 0-521-60124-X paperback
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Contents
Preface pagexiii
Notetoinstructors xv
Acknowledgements xvi
Generalconventions xvii
Listofabbreviations xviii
0 TCP/IP overview 1
0.1 TheInternet 1
0.2 TCP/IP protocols 2
0.3 Internetworkingdevices 5
0.4 Encapsulationandmultiplexing 7
0.5 Namingandaddressing 8
0.6 Multipleaccess 15
0.7 Routingandforwarding 16
0.8 Congestioncontrolandflowcontrol 17
0.9 Errordetectionandcontrol 18
0.10 Headerformatsoftheprotocols 19
0.11 Anexample:howTCP/IPprotocolswork
together 22
1 Linux and TCP/IP networking 26
1.1 Objectives 26
1.2 LinuxandTCP/IPimplementations 26
1.3 Linuxcommandsandtools 31
1.4 Diagnostictools 35
vii
viii Contents
1.5 ExerciseswithLinuxcommands 36
1.6 Exerciseswithdiagnostictools 39
1.7 Exercisesonportnumbers 41
2 A single segment network 43
2.1 Objectives 43
2.2 Localareanetworks 43
2.3 Networkinterface 50
2.4 TheInternetControlMessageProtocol 52
2.5 TheSocktrafficgenerator 54
2.6 Networkinterfaceexercises 54
2.7 ARPexercises 55
2.8 ExerciseswithICMPandping 58
2.9 ExerciseswithIPaddressandsubnetsmask 59
3 Bridges, LANs and the Cisco IOS 61
3.1 Objectives 61
3.2 Ethernetbridges 61
3.3 Configuringabridgeorrouter 66
3.4 ExercisesonCiscoIOS 71
3.5 Asimplebridgeexperiment 73
3.6 Spanningtreeexercises 75
3.7 ExerciseontheCiscoIOSwebbrowserUI 76
4 Static and dynamic routing 77
4.1 Objectives 77
4.2 Staticanddynamicrouting 77
4.3 Manipulatingroutingtables 89
4.4 Traceroute 90
4.5 Asimplerouterexperiment 91
4.6 RIPexercises 93
4.7 RoutingexperimentswithICMP 95
ix Contents
4.8 OSPFexercise 97
4.9 Staticroutingexperiment 98
4.10 Tracerouteexperiment 99
5 UDP and its applications 100
5.1 Objectives 100
5.2 TheUserDatagramProtocol 100
5.3 MTUandIPfragmentation 101
5.4 Client–serverapplications 102
5.5 Usingthesockprogram 106
5.6 UDPexercises 106
5.7 PathMTUdiscoveryexercise 107
5.8 ExerciseswithFTPandTFTP 108
6 TCP study 111
6.1 Objectives 111
6.2 TCPservice 111
6.3 ManagingtheTCPconnection 112
6.4 ManagingtheTCPdataflow 114
6.5 TuningtheTCP/IPkernel 123
6.6 TCPdiagnostictools 124
6.7 ExercisesonTCPconnectioncontrol 126
6.8 ExerciseonTCPinteractivedataflow 127
6.9 ExerciseonTCPbulkdataflow 128
6.10 ExercisesonTCPtimersandretransmission 128
6.11 Otherexercises 129
6.12 ExerciseswithDBSandNISTNet 130
7 Multicast and realtime service 134
7.1 Objectives 134
7.2 IPmulticast 134
x Contents
7.3 Realtimemultimediastreaming 145
7.4 Simplemulticastexercises 152
7.5 IGMPexercises 154
7.6 Multicastroutingexercises 156
7.7 Multicastvideostreamingexercise 158
8 The Web, DHCP, NTP and NAT 159
8.1 Objectives 159
8.2 TheHyperTextTransferProtocol 159
8.3 TheDynamicHostConfigurationProtocol 164
8.4 TheNetworkTimeProtocol 169
8.5 TheIPnetworkaddresstranslator 172
8.6 Socketprogramminginanutshell 175
8.7 HTTPexercises 178
8.8 DHCPexercises 180
8.9 NTPexercises 181
8.10 NATexercises 182
8.11 Socketprogrammingexercises 185
9 Network management and security 187
9.1 Objectives 187
9.2 Networkmanagement 187
9.3 Networksecurityoverview 192
9.4 Encryption,confidentiality,andauthentication 193
9.5 Applicationlayersecurity 198
9.6 Transportlayerandwebsecurity 200
9.7 Networklayersecurity 203
9.8 Systemsecurity 205
9.9 SNMPexercises 208
9.10 Exercisesonsecureapplications 209
9.11 ExercisesonasecureApacheserver 210
9.12 Exercisesonfirewallsandiptables 211
9.13 Exercisesonauditingandintrusiondetection 212
xi Contents
References and further reading 214
Appendix A: instructor’s guide 216
A.1 Laboperationmechanism 216
A.2 Labequipment 217
A.3 Softwareinstallationandconfiguration 219
A.4 Estimatedbudget 229
A.5 Rootprivilegeforsystemcommands 230
A.6 Internetaccess 232
Appendix B: initial configuration of the routers 233
B.1 Initialconfigurationofrouter1 233
B.2 Initialconfigurationsoftheotherrouters 235
Appendix C: source code 236
C.1 CommandfilesfortheDBSexperiments 236
C.2 Netspysourcecode 239
C.3 HTMLandCGIfiles 245
C.4 Socketprogrammingsourcecode 246
Appendix D: list of key requests for comments (RFC) 253
Index 258
Preface
Youcanknowthenameofabirdinallthelanguagesoftheworld,butwhen
you’refinished,you’llknowabsolutelynothingwhateveraboutthebird...So
let’slookatthebirdandseewhatit’sdoing–that’swhatcounts.Ilearnedvery
earlythedifferencebetweenknowingthenameofsomethingandknowing
something. RichardFeynman(1918–1988)
As the title of this book suggests, this book is a minimalist approach to
teaching TCP/IP using laboratory-based experiments. It is minimalist in
that it provides one, possibly idiosyncratic, choice of topics at a depth
we felt was sufficient to learn the basics of TCP/IP. The intention was
not to write a reference text on the subject. The laboratory was important
in giving students the experience of observing the TCP/IP protocols in
action. The act of observing and drawing some conclusions from those
observations, brings to life the often dry study of network protocols, and
motivatesstudentstolearnmoreaboutthem.
AppendixAisnecessaryreadingonlyfortheinstructorwhoisincharge
ofsettingupthelab.Wehaveattemptedtokeepcostsdownsothatonlythe
most Scrooge-like University administrator would raise an eyebrow over
the cost of the lab equipment (as for lab space, that may be another mat-
ter!).Weassumethatthestudentshaveabasicbackgroundinnetworking,
perhaps from a previous course, or perhaps as part of a course that back
loadstheexperimentsinthisbookafterprovidingagenerallecture-based
introduction to networks. Chapter 0 is a quick overview of TCP/IP that
serves two purposes. It provides an overview of the TCP/IP stack, and
servesastheframeworkfortherestofthebook.Chapters1to9havethe
followingcommonstructure.Eachofthemprovidesintroductorymaterial
suitableforpresentationinthelecturepartofthecoursefollowedbyalab
experiment. The lab experiments should follow lectures that provide the
xiii
xiv Preface
students with the basic knowledge they need to perform the experiments
andderiveinsightsfromtheirobservationsduringthecourseoftheexper-
iments. Each lab experiment is designed to take no more than 3 hours to
complete.
The experiments were developed on the basis of a course taught at
the Polytechnic University over the course of over eight years. Initially,
we used SUN workstations with the Solaris operating system, but have
now switched to Linux machines. The primary operating system in this
book is Linux, but with Solaris commands provided when they differ
from Linux commands. Chapter 1 provides an introduction to Linux,
sincemanystudentsmaybeunfamiliarwiththisoperatingsystem.Italso
introduces key tools used in subsequent experiments such as tcpdump
and Ethereal. Chapter2 introduces network interfaces, ping and IP ad-
dresses. Chapter3 introduces bridges, also known as layer two switches,
bridge/routerconfiguration,andtheCiscoIOS.Chapter4focusesonrout-
ing, with RIP and OSPF as the routing protocols studied, along with the
useful traceroute utility. Chapter 5 introduces UDP and FTP. Chapter 6
follows up with TCP, including a study of its congestion control mecha-
nism.Thesesixchaptersaresufficientinmanycasestointroducestudents
tothebasicsofTCP/IP.Nonetheless,thenextthreechaptersareimportant
for students who wish to link the basic plumbing of TCP/IP with appli-
cations. Chapter 7 deals with IP multicast and realtime applications. The
web, DHCP, NTP and NAT are some key applications that are presented
in Chapter 8, as well as a brief introduction to socket programming. Net-
work management and security are arguably two of the most important
features that students need to know, at least at a basic level. Chapter 9
providesabriefintroductiontothismaterial,whichcaneasilybethesub-
ject of a separate course. A list of key RFCs is provided at the end of the
book.
There are several alternative ways of teaching this material with this
book.Ageneralknowledgeofnetworkingisassumedasaprerequisitefor
this book. However, an introductory course in networking could be com-
binedwiththefirstsixexperiments,back-loadedattheendofthecourse,to
illustratethelowestfourlayersoftheprotocolstack.Forcomputerscien-
tists,atop-downapproachissometimesthepreferredapproachinteaching
networking.Inthatcasethelabexperimentscanbere-orderedtofocuson
thehigherlayers.
xv Preface
Notetoinstructors
Additional course material, including lecture transparencies, sample lab
reports,homeworkassignments,examinations,anderrata,areavailableat
thecoursewebsite:www.cambridge.org/052160124X.