i Contents i-Net+ Certification Study Guide Introduction ..................................................................... xxv Who Should Study this Course ............................................... xxv Prerequisites ............................................................................ xxv Important Notes About Certification ............................................ xxv Exam Objectives ..................................................................... xxvi How to Study .......................................................................... xxvi Features .............................................................................................. xl Learning Objectives, Unit Summaries, Discussion Questions, and Activities/Exercises .................................................................. xl Key Terms .......................................................................................... xl Resources Available in Instructor-led Settings .................................. xl Why Choose WestNet? .................................................................... xli CompTIA Authorized Quality Curriculum (CAQC) ........................ xli What's the best way to study for CompTIA certifications? ...... xli What types of programs does CompTIA evaluate? .................. xlii How can I tell if a training material is CompTIA Authorized Quality Curriculum? .......................................... xlii How does CompTIA authorize these programs? ..................... xlii Why did CompTIA develop the Authorization program? ....... xlii What if the CompTIA logo is used? Does the CompTIA logo signify CAQC? .............................................. xlii How can I learn more about CompTIA CAQC program? ....... xliii CAQC ............................................................................................. xliii How to Become CompTIA Certified .............................................. xliii
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Who Should Study this Course ............................................... xxvPrerequisites ............................................................................ xxv
Important Notes About Certification ............................................ xxvExam Objectives .....................................................................xxviHow to Study ..........................................................................xxvi
Features ..............................................................................................xlLearning Objectives, Unit Summaries, Discussion Questions,
and Activities/Exercises ..................................................................xlKey Terms ..........................................................................................xlResources Available in Instructor-led Settings ..................................xlWhy Choose WestNet? ....................................................................xliCompTIA Authorized Quality Curriculum (CAQC) ........................xli
What's the best way to study for CompTIA certifications? ......xliWhat types of programs does CompTIA evaluate? ..................xliiHow can I tell if a training material is CompTIA
Authorized Quality Curriculum? ..........................................xliiHow does CompTIA authorize these programs? .....................xliiWhy did CompTIA develop the Authorization program? .......xliiWhat if the CompTIA logo is used? Does the
CompTIA logo signify CAQC? ..............................................xliiHow can I learn more about CompTIA CAQC program? .......xliii
CAQC .............................................................................................xliiiHow to Become CompTIA Certified ..............................................xliii
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Unit 1Review of Network Fundamentals ......................................1
Lesson 1Internal Computer Components: CPU, I/O, Memory, and NICs ................................................................9
CPU ....................................................................................................9I/O ....................................................................................................10
Video Display ............................................................................12Memory ............................................................................................12NICs ..................................................................................................13
Different Networks, Different NICs ..........................................13Each NIC is Unique ...................................................................14NIC Connectivity in a PC .........................................................14Summary of NIC Characteristics ...............................................15
Types of Networks ............................................................................25Bus Topology ....................................................................................26Star Topology ...................................................................................27Ring Topologies ................................................................................28
Ring ...........................................................................................28Star Ring ....................................................................................30
Wide Area Topologies ......................................................................31Mesh ..........................................................................................32Network Cloud ..........................................................................33
Advantages of Cloud Networks ..........................................34Hybrid Topologies ............................................................................34Logical and Physical Topologies ......................................................34
Physical Star, Logical Bus ..........................................................34Physical Star, Logical Ring ........................................................35
Response Time, Delay, and Latency ................................................39Response Time in a Master/Slave Configuration .............................40
Response Time in a Client/Server Configuration ............................41NIC Delay ..................................................................................42Physical Media Delay ................................................................42Server Delay ...............................................................................42Public Network Delay ................................................................42
CPU Utilization ................................................................................43Link Utilization ................................................................................44
Lesson 5Review of the OSI Model .....................................................48
Programs, Processes, and Protocols ..................................................48Protocols ....................................................................................49
Layers of Protocols and Services ......................................................49Benefits of Layering ...................................................................50Peer Protocols ............................................................................50Basic Protocol Operations .........................................................50
Primary Functions of OSI Model Layers ..........................................51Physical Layer ............................................................................52Data Link Layer .........................................................................52Network Layer ...........................................................................53Transport Layer .........................................................................54Upper Layers: Session, Presentation, and Application .............54
Logical and Physical Addresses ........................................................55Physical Addresses .....................................................................55Logical Addresses .......................................................................56
Lesson 6Review of Internetworking Devices ......................................59
Repeaters ..........................................................................................59Repeater Advantages .................................................................60Repeater Disadvantages .............................................................60When to Use Repeaters .............................................................61
Hubs .................................................................................................61Hub Advantages ........................................................................61Hub Disadvantages ....................................................................63When to Use Hubs ....................................................................63
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Bridges ..............................................................................................63Bridge Advantages .....................................................................64Bridge Disadvantages ................................................................65When to Use Bridges .................................................................66
Switches ............................................................................................66Switch Advantages ....................................................................68Switch Disadvantages ................................................................68When to Use Switches ...............................................................69
Routers ..............................................................................................69Routers Rebuild Frames .............................................................70Internet Routers ........................................................................71Router Advantages ....................................................................71Router Disadvantages ................................................................72When to Use Routers ................................................................72
Gateway Advantages .................................................................74Gateway Disadvantages .............................................................74When to Use Gateways .............................................................74
Unit 2E-Commerce .......................................................................87
Lesson 1E-Commerce Business Considerations ..................................93
Types of E-Commerce ......................................................................93B2C ............................................................................................94
Growing Share of the Retail Market ...................................94B2B ............................................................................................94C2C or Marketplace ..................................................................95C2B ............................................................................................95B2E .............................................................................................96B2G ............................................................................................96Aggregator Model ......................................................................97Portal Model ..............................................................................97
Necessary Features of E-Commerce Sites .........................................99Is E-Commerce Worthwhile for Every Business? ...........................100Barriers to Entering the E-Commerce Arena ..................................100
Incompatible Business Models ................................................101Lack of Leadership and Experience .........................................101Cost of Entry ...........................................................................101
Lesson 2Globalization and Localization ...........................................103
Speaking the Language ..................................................................104Localized Content ...................................................................105The High-End Approach: Region-Specific Sites ......................105The Low-End Approach: Translation Links ............................106Search Engine Hooks ...............................................................106
Laws and Regulations .....................................................................106Your Products ..........................................................................107
United States Law .............................................................107Your Expression .......................................................................108Your Business Methods ...........................................................108
Currency ..................................................................................109Time Zones and Calendars ......................................................110Social Values and Customs .....................................................111
Lesson 4E-Commerce Development Options ..................................125
Technical Considerations for E-Commerce Applications ..............125Web Server and Database Issues .............................................126Application Business Logic .....................................................126
Buy, Build, or Outsource? ..............................................................127Buy a Turn-Key Development Package ...................................128Build with a Template-Based Development Package ..............128Build with a Fully Custom Application Toolkit ......................129Outsource to an Application Service Provider ........................129
Four Types of Intellectual Property ................................................134Copyright .......................................................................................134
What Is Protected? ..................................................................134What is Not Protected? ...........................................................136How a Work Gains Protection ................................................136
Infringement ...........................................................................138Fair Use ....................................................................................138
Trademarks .....................................................................................139What is Protected? ..................................................................139Limits to Trademark Protection ..............................................140How a Trademark is Claimed and Protected ..........................140Infringement ...........................................................................142Domain Names and Trademarks .............................................142
Patents ............................................................................................142Patents and the Web ...............................................................143
Lesson 6Crime, Privacy, and Other Legal Issues ...............................147
Crime and the Internet ..................................................................148New Frontier, Old Crimes .......................................................148New Laws, New Crimes ...........................................................149
Geography, Crime, and the Web ...................................................152Obscenity and Community Standards ..........................................153Contracts and Civil Law .................................................................153Lawsuits and Jurisdiction ...............................................................154Framing and Deep Linking ............................................................155DMCA .............................................................................................156
Limitation of Liability for Online Service Providers ...............156“Trafficking” in Copy- and Access-Control Devices ...............157
Under Construction .......................................................................157Activities .........................................................................................158
Unit 3Internet Connectivity Technologies ................................167
Lesson 1Overview of the Internet ....................................................173
Early History of the Internet ..........................................................173Enter the World Wide Web ...........................................................174Who Owns the Internet? ...............................................................175Internet Standards ..........................................................................175
Standards-Making Organizations ............................................175The Standards Process .............................................................176RFC ..........................................................................................177Internet Drafts .........................................................................178
Equipment ......................................................................................179The Internet Hierarchy ..................................................................179
Tier 1 .......................................................................................179Tier 2 .......................................................................................180Autonomous Systems ..............................................................180NAPs ........................................................................................180 ISPs .........................................................................................181How the Hierarchy Works ......................................................181
Internet, intranet, and Extranet .....................................................181Activities .........................................................................................183
Lesson 2Point-to-Point and Point-to-Multipoint Services .................184
Common Point-to-Point Services ..................................................185POTS Analog Connections .............................................................185
Common Point-to-Multipoint Services .........................................197DSL .................................................................................................198
Types of DSL Service ...............................................................199DSL Bandwidth ................................................................200DSL Physical Requirements ..............................................200
Lesson 4Options for Internet Connectivity and Remote User Access ...........................................................221
Home Dial-Up Internet Access .......................................................222Data Link Protocols for Dial-Up Access ..................................223
Microsoft ICS ...........................................................................224Setting Up the ICS Gateway .............................................225Setting Up ICS Clients ......................................................225ICS Security Precautions ...................................................226
DSL for Home Internet Connectivity ............................................226Sharing a DSL Connection ......................................................226
Pay for Fixed IP Addresses ................................................227Internet Connection Sharing ...........................................227PPPoE ................................................................................227
Connecting a Business to an ISP ....................................................227Nondedicated Access ...............................................................228Dedicated Access .....................................................................229Components of a Dedicated Connection ...............................229
Common Carrier Connection ..........................................229DSU/CSU ..........................................................................230Router ...............................................................................230
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Internet Domain Name ....................................................230Remote Access Services ..................................................................231
Unit 4TCP/IP Protocols ..............................................................249
Lesson 1The TCP/IP Protocol Suite ..................................................256
TCP/IP Protocol Layers and the OSI Model ...................................256Network Interface Layer Protocols ..........................................257Internetwork Layer Protocols ..................................................257Transport Layer Protocols .......................................................258Application Layer Protocols ....................................................259
Communication Using TCP/IP ......................................................260Application Layer ....................................................................260Transport Layer .......................................................................260Network Layer .........................................................................261Network Interface Layer ..........................................................262Destination Station .................................................................262
Overview of IP ................................................................................265Best-Effort Service ....................................................................266Multiplexing Protocols ............................................................267
IP Packet Encapsulation .................................................................268IP Version 6 ....................................................................................268
IPv6 Address Format ................................................................269IPv4 Compatibility ..................................................................270
ICMP ...............................................................................................270ICMP’s Purpose and Limits .....................................................270Encapsulation ..........................................................................271Message Types .........................................................................272
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Destination Unreachable (3) ............................................273Time Exceeded (11) ..........................................................273Parameter Problem (12) ....................................................273Source Quench (4) ............................................................273Redirect (5) .......................................................................274Echo Request (8) and Echo Reply (0) ...............................274Timestamp Request (13) and Timestamp
Reply (14) ......................................................................274Information Request (15) and Information
Reply (16) ......................................................................274Address Mask Request (17) and Address Mask
Lesson 3UDP and TCP .....................................................................278
Features Common to Both UDP and TCP .....................................279Demultiplexing Based on Port Number ..................................280Ports and Addressing ...............................................................281Well-Known Port Numbers .....................................................282
Basic Data Transfer ..................................................................284Reliable and Sequenced Packet Delivery .................................284Flow Control ...........................................................................284Multiplexing and Demultiplexing ..........................................285Connection Establishment .....................................................285
IP Addresses ....................................................................................289Class A Address ........................................................................290Class B Address ........................................................................290Class C Address .......................................................................291Class D Address .......................................................................291Class E Address ........................................................................292
Dotted Decimal Notation ...............................................................292Addressing Rules ............................................................................293Sample Network Using Class A Address Format ............................294Getting an IP Network Address ......................................................295
Public Networks ......................................................................295Private Networks .....................................................................295
The Value of Subnetting ................................................................299The IP Address Crisis ...............................................................300Why Multiple Network Segments? .........................................300
CIDR ...............................................................................................305How CIDR Works ....................................................................305
Overview of Internet Architecture .................................................311Router Characteristics .............................................................312
Direct Routing ................................................................................312Indirect Routing .............................................................................314
Building the Routing Table ............................................................317Sample Network Routing Table ..............................................318
How Routers Move Packets Between Networks .............................320Host A ......................................................................................321Packet on Network 128.1.0.0 ..................................................321Packet on Network 128.2.0.0 ..................................................322Packet on Network 128.3.0.0 ..................................................323Packet on Network 128.4.0.0 ..................................................324Host B ......................................................................................324
Common Telnet Uses .....................................................................356Telnet Server Software ....................................................................357Using Telnet by Means of a Command Line .................................357
Using Telnet With Windows ..................................................358Basic Telnet Commands ..........................................................359
Using Telnet by Means of a Web Browser .....................................360Activities .........................................................................................361
Why Use FTP? ................................................................................363FTP Server Software ........................................................................364Anonymous FTP .............................................................................364
Is Anonymous FTP Really Anonymous? .................................365Using FTP Clients ...........................................................................365
Using Command Line FTP ......................................................366Basic FTP Commands ..............................................................368Using FTP With a Browser .......................................................369Same Application, Different Interfaces ...................................370
Mail Server Configuration ..............................................................376Store-and-Forward Mail Systems .............................................377
How NAPT Works ............................................................397NAPT for More Security ...................................................399
Domain Names ........................................................................410Types of Domain Names ..................................................411Domain Name Syntax ......................................................411
DNS Client/Server Operation ..................................................411Name Servers ....................................................................412Resolvers ...........................................................................413Querying the Name Database ..........................................413
NetBIOS Name Resolution .............................................................414Broadcasts .........................................................................414LMHOSTS file ...................................................................414
Incompatible Systems .............................................................415Static vs. Dynamic ...................................................................415
Internet Explorer ..............................................................436Netscape Navigator ..........................................................441
E-Mail Clients .................................................................................447Configuring Outlook Express ..................................................447Configuring Netscape Messenger ............................................449Inboxes and Address Books .....................................................449
Changing E-Mail Applications .........................................449Upgrading the Same E-Mail Application .........................449
Server Components ........................................................................460Hardware Considerations ...............................................................461
Web Server Operating System Considerations ..............................464Desktop Operating Systems ....................................................464NOSs ........................................................................................465
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Apple Macintosh (Mac OS) ..............................................465Microsoft Windows 2000 .................................................465Microsoft Windows NT ....................................................466OS/2 Warp Server .............................................................466Commercial UNIX ............................................................467Linux ................................................................................467Novell NetWare ................................................................468
UNIX vs. Windows 2000 .........................................................469Administration .................................................................469Stability ............................................................................470Security .............................................................................470Product Availability ..........................................................471
Daemons and Services ....................................................................477Web Server Software .......................................................................477
Apache HTTP Server ................................................................478Microsoft IIS ............................................................................479Netscape/Sun iPlanet Web Server ...........................................480Other Web Server Choices ......................................................481
Zeus Web Server ...............................................................481Macromedia ColdFusion ..................................................481IBM WebSphere Application Server .................................481Oracle Application Server .................................................481
Web Server Software Considerations .............................................481Administration ........................................................................482Scalability ................................................................................482Server Management .................................................................482Security ....................................................................................483Multiple URL Hosting .............................................................483Product Integration .................................................................483
Server Tools ......................................................................484Development Tools ..........................................................484Web Browsers ...................................................................484
Vendor-Specific Features and Service Contracts .....................485Other Internet Servers ....................................................................485
Unit 7Building Web Pages .........................................................495
Lesson 1Creating Basic Web Pages ..................................................500
HTML Overview .............................................................................500Basic HTML Elements .....................................................................501
Basic Tag Types ........................................................................501Container Tags .................................................................501Empty Tags .......................................................................501
Tag Names ...............................................................................501Browser Versions and Tags ......................................................501Main Page Sections ..................................................................502Page Structure ..........................................................................502Attributes .................................................................................503
Create a Simple Web Page ..............................................................503Heading Tags ...........................................................................505Are End Tags Really Necessary? ...............................................505Plain Text ................................................................................506
Experiment With Heading Levels, Line Breaks, and Lists .............506Testing the Heading Levels .....................................................506Inserting Line and Paragraph Breaks ......................................507Creating Ordered and Unordered Lists ...................................508
Organizing Your HTML Code ........................................................510<META> Tags ..................................................................................511
Inserting Horizontal Rules .............................................................516Inserting Graphic Files ...................................................................518Experiment With Inserting Graphic Files ......................................519Adding a Background .....................................................................522
Solid Color Backgrounds .........................................................522Repeating Graphic Backgrounds .............................................522A Word of Caution About Backgrounds .................................523
Creating a Text Hyperlink ..............................................................527Creating a Relative Hyperlink ........................................................528Creating a Link From a Graphic ....................................................528Creating Links to Other Parts of the Current Page ........................528Activities .........................................................................................530
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Lesson 4Formatting Text .................................................................531
Setting Default Text Attributes ......................................................531Text Color ...............................................................................531Link Text Color .......................................................................532Default Text Font ....................................................................532Default Text Size .....................................................................532Setting Multiple Default Attributes .........................................533
Setting Individual Text Attributes ..................................................533Activities .........................................................................................535
The Parts of a Table ........................................................................536Create a Table ..........................................................................536Add Formatting to Your Table ................................................538Add Cells to the Table Row .....................................................539More Table and Cell Formatting .............................................540
Lesson 7Using Forms ......................................................................551
Overall Form Attributes .................................................................551Form Fields and Controls ........................................................552
Hidden Form Fields ..........................................................552Drop-Down List Boxes ............................................................553Freeform Text Boxes ................................................................553
Manipulating the Form’s Data .......................................................554Creating a Test Form ...............................................................554
Challenges for the Multimedia Web Designer ..............................563Computer Hardware Limitations ............................................564Internet Connection Bandwidth ............................................564Color Inconsistencies ..............................................................564
How Streaming Works ...................................................................572Plug-In Technology ........................................................................573Streaming Audio Formats ...............................................................574
Streaming and Playback Performance ..............................578Virtual Reality Modeling Language ........................................579
Streaming Video Formats ...............................................................579RealVideo ................................................................................580Windows Media Player ...........................................................580
Unit 8Dynamic Site Technologies .............................................595
Lesson 1Dynamic Sites and Databases ............................................600
The Need for Live Sites ...................................................................600Types of Dynamic Techniques .......................................................601
Gathering Data From Outside Sources ....................................601Time-Sensitive Pages ...............................................................601User-Supplied Data ..................................................................602Database-Driven Sites ..............................................................602
Database Concepts .........................................................................602Database Management Systems .....................................................603
A Typical CGI Process ....................................................................610Exchanging Data With CGI ...........................................................611
Standard Input/Output (I/O) ..................................................611Environment Variables ...........................................................612
Difference Between GET and POST ................................................613GET Uses Environment Space .................................................613POST Uses Standard Input/Output (I/O) ................................614
Placing CGI Programs on a Web Server .........................................614Activities .........................................................................................615
Lesson 3Overview of Web Programming Technologies ...................616
Client-Side vs. Server-Side Scripting ..............................................616When to Run on the Client ....................................................617When to Run on the Server ....................................................618
Programming Languages and Tools ...............................................618Client-Side Technologies ........................................................619
The Need to Separate Content From Appearance .........................628Cascading Style Sheets ............................................................629
Structured Data ..............................................................................629SGML .......................................................................................630
XML ................................................................................................630Structured Data Means Independence ....................................630The XML Architecture .............................................................631
Elements ...........................................................................631Attributes ..........................................................................631DTD ..................................................................................631
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Applications of XML ...............................................................632Complementary Standards ............................................................632
Unit 9Troubleshooting ..............................................................639
Lesson 1Testing a Web Site and Web Server ...................................643
Overview of Systems Development Life Cycles .............................643Waterfall Cycle ........................................................................644Spiral Cycle ..............................................................................645Web Cycle? ..............................................................................646
Typical Levels of Testing ................................................................646Testing Principles ...........................................................................647
Follow the User .......................................................................647Testing Basic Site Functionality ..............................................647Stress Testing ...........................................................................648
A Few Testing Guidelines ...............................................................649Activities .........................................................................................651
Tracert or Traceroute ......................................................................660Command-Line Switches ........................................................662
Netstat ............................................................................................662Command-Line Switches ........................................................664Repeating a Netstat Command ...............................................664
ARP .................................................................................................664How ARP Works ......................................................................665ARP for Troubleshooting .........................................................665Command-Line Switches ........................................................665Changing the ARP Cache ........................................................666
Lesson 3Troubleshooting an Unreachable FTP Site ..........................675
The Problem ...................................................................................676Establish the Symptoms ..........................................................676Identify the Affected Area .......................................................676Establish What Has Changed ..................................................676Select the Most Probable Cause ..............................................677Implement a Solution .............................................................677Test the Result .........................................................................677Recognize the Potential Effects of the Solution ......................678Document the Solution ..........................................................678
Lesson 4Troubleshooting an Unreachable Web Site ........................680
The Problem ...................................................................................680Establish the Symptoms ..........................................................680Identify the Affected Area .......................................................680Establish What Has Changed ..................................................681Select the Most Probable Cause ..............................................681
Testing Internal Communications ...................................683Testing ISP Communications ...........................................684Testing Web Host Firm Communications .......................685Tallying the Test Results ..................................................685Isolating the Cause ...........................................................686
Implement a Solution .............................................................687Test the Result .........................................................................687Recognize the Potential Effects of the Solution ......................688Document the Solution ..........................................................688
Lesson 5Troubleshooting a Firewall Problem ...................................691
The Environment ...........................................................................691The Problem ...................................................................................692
Establish the Symptoms ..........................................................692Identify the Affected Area .......................................................692Establish What Has Changed ..................................................693Select the Most Probable Cause ..............................................693
Pause to Administer First Aid ...........................................693Continue to Isolate the Problem ......................................693
Implement a Solution .............................................................694Test the Result .........................................................................694Recognize the Potential Effects of the Solution ......................695Document the Solution ..........................................................695
Lesson 6Troubleshooting a Home Office DSL Problem ....................697
The Environment ...........................................................................697The Problem ...................................................................................698
Establish the Symptoms ..........................................................698Identify the Affected Area .......................................................699Establish What Has Changed ..................................................700Select the Most Probable Cause ..............................................700Implement a Solution .............................................................700Test the Result .........................................................................701Recognize the Potential Effects of the Solution ......................701Document the Solution ..........................................................701
Layers of Security ...........................................................................718Security Policy .........................................................................719User Awareness Training .........................................................719
Acceptable Use Agreement ...............................................719Monitoring .......................................................................719Enforcement .....................................................................720
Key Size and Encryption Strength ...................................724Legal Issues in Cryptography ...........................................724Commonly Used Encryption Systems .............................724
Access Control .........................................................................727User Authentication ................................................................727
Passwords .........................................................................728Smart Cards ......................................................................728Digital Certificates ............................................................729Biometric Authentication ................................................729Message Digests and Digital Signatures ...........................730
Firewalls ...................................................................................731IPSec ........................................................................................731Virus Prevention and Detection .............................................733Security Management .............................................................734
Types of Attacks .............................................................................738Multiple Login Failures ...........................................................739Denial of Service Attacks .........................................................739
IP Spoofing ..............................................................................739General Web Security Precautions .................................................740
Private Web Site Design ..........................................................740HTTP Server Access Control .............................................740
Responding to a Security Incident .................................................748Detection .................................................................................748Documentation .......................................................................749Communication ......................................................................749
Stance of a Firewall .........................................................................755Everything is Denied Unless Specifically Permitted ...............756Everything is Permitted Unless Specifically Denied ...............756
Cost of a Firewall ............................................................................756Components of a Firewall System .................................................756
Building Block: Packet-Filtering Router ..................................757Service-Dependent (Port) Filtering ...................................758Service-Independent Filtering ..........................................758Benefits of Packet-Filtering Routers .................................759Limitations of Packet-Filtering Routers ............................759Example 1: Packet-Filtering Router ..................................760
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Building Block: Application-Level Gateway (Proxy Server) ....761Bastion Host .....................................................................762Example 2: Telnet Proxy ..................................................763Advantages of Proxy Servers ............................................765Disadvantages of Proxy Servers ........................................765
Building Block: Circuit-Level Gateway ...................................766SOCKS ...............................................................................767
Web Caching ...........................................................................768“Faster” or “Fresher” ........................................................769Example 3: Screened Host Firewall ..................................770Example 4: Dual-Homed Bastion Host ............................771Example 5: “Demilitarized Zone” or
Screened-Subnet Firewall ..............................................772Living With a Firewall ....................................................................773Activities .........................................................................................775