Introduction... 1
Self-Assessment... 7
Chapter 1:
Introduction to Networking..................................................................... 13
Introduction.............................................................................. 14
LANs, WANs, MANs, and WPANs............................................ 14
LANs........................................................................... 14
WANs......................................................................... 15
Metropolitan Area Networks (MANs)............................... 15
WPANs....................................................................... 15
Network Models....................................................................... 16
Peer-to-Peer Networking Model...................................... 16
Client/Server Networking Model...................................... 16
Comparing Peer-to-Peer and Client/Server Network Models 17
Centralized and Distributed Computing....................................... 18
Virtual Private Networks (VPNs)................................................. 18
Components of the VPN Connection.............................. 19
VPN Pros and Cons..................................................... 20
Virtual Local Area Networks (VLANs)......................................... 21
VLAN Membership....................................................... 23
Network Topologies.................................................................. 26
Bus Topology............................................................... 26
Ring Topology.............................................................. 27
Star Topology............................................................... 28
Wired Mesh Topology................................................... 30
Wireless Topologies..................................................... 31
Point-to-Point, Point-to-Multipoint, and Wireless Mesh Topologies 33
Hybrid Topologies......................................................... 36
Review and Test Yourself.......................................................... 37
The Facts.................................................................... 37
Key Terms................................................................... 38
Exam Prep Questions................................................... 39
Answers to Exam Prep Questions................................. 41
Need to Know More?................................................................ 42
Chapter 2:
Cabling, Connectors, and Ethernet Standards......................................... 43
Introduction.............................................................................. 45
General Media Considerations................................................... 45
Broadband Versus Baseband........................................ 46
Simplex, Half Duplex, and Full Duplex............................ 46
Media Interference........................................................ 46
Attenuation.................................................................. 47
Data Transmission Rates.............................................. 48
Network Media......................................................................... 48
Twisted-Pair Cabling..................................................... 49
Coaxial........................................................................ 52
Fiber-Optic Cable......................................................... 53
Plenum Cables............................................................. 56
Media Connectors.................................................................... 56
BNC Connectors.......................................................... 56
RJ-11 Connectors......................................................... 57
RJ-45 Connectors......................................................... 58
F-Type Connectors and RG-59 and RG-6........................ 59
Fiber Connectors.......................................................... 59
RS-232 Standard.......................................................... 61
IEEE 1394................................................................... 62
Universal Serial Bus (USB)............................................ 62
568A and 568B Wiring Standards.............................................. 63
Straight Versus Crossover Cable................................................ 64
Rollover and Loopback Cables................................................... 66
Loopback Cable........................................................... 66
Components of Wiring Distribution............................................. 66
Network Cross-Connects............................................... 67
Horizontal Cabling........................................................ 67
Vertical Cable.............................................................. 69
Patch Panels............................................................... 69
Type 66 and Type 110 Punchdown Blocks...................... 71
MDF and IDF............................................................... 71
Demarc, Demarc Extension, and Smart Jacks................ 72
Verify Wiring Installation and Termination........................ 74
IEEE and Overview of Networking Standards............................... 75
IEEE 802.2 Standard.................................................... 76
IEEE 802.3x Standard Characteristics............................ 76
802.3 Ethernet Standards.......................................................... 81
10BaseT...................................................................... 81
10BaseFL.................................................................... 82
Fast Ethernet............................................................... 82
Gigabit Ethernet: 1000BaseX......................................... 84
1000BaseT.................................................................. 85
10 Gigabit Ethernet....................................................... 86
10GBaseT................................................................... 88
Review and Test Yourself.......................................................... 88
The Facts.................................................................... 89
Key Terms................................................................... 90
Exam Prep Questions................................................... 90
Answers to Exam Prep Questions................................. 93
Need to Know More?................................................................ 94
Chapter 3:
Networking Components and Devices..................................................... 95
Introduction.............................................................................. 96
Hubs....................................................................................... 96
MSAU..................................................................................... 97
Switches................................................................................. 98
Hub and Switch Cabling................................................ 99
Bridges.................................................................................. 100
Bridge Placement and Bridging Loops.......................... 101
Types of Bridges......................................................... 101
Routers.................................................................................. 102
Gateways.............................................................................. 103
Network Cards........................................................................ 104
Types of Network Interfaces......................................... 104
Installing Network Cards.............................................. 105
Media Converters.................................................................... 106
Wireless Access Points.......................................................... 107
Modems................................................................................ 108
Firewalls................................................................................ 110
DHCP Server.......................................................................... 111
Repeaters.............................................................................. 112
Specialized Network Devices................................................... 112
Multilayer and Content Switches.................................. 113
Intrusion Detection and Prevention Systems.................. 114
Load Balancer............................................................ 115
Multifunction Network Devices...................................... 115
DNS Server................................................................ 116
Bandwidth Shaper....................................................... 117
Proxy Server.............................................................. 118
CSUs/DSUs............................................................... 120
Network Devices Summary.......................................... 121
Advanced Features of a Switch................................................ 123
Power over Ethernet (PoE)........................................... 123
Spanning Tree............................................................ 124
Trunking..................................................................... 125
Port Mirroring............................................................. 126
Port Authentication..................................................... 126
Review and Test Yourself......................................................... 126
The Facts.................................................................. 126
Key Terms................................................................. 128
Exam Prep Questions................................................. 129
Answers to Exam Prep Questions................................ 131
Need to Know More?............................................................... 132
Chapter 4:
OSI Model and Network Protocols........................................................ 133
Introduction............................................................................ 134
The OSI Seven-Layer Model..................................................... 134
Physical Layer (Layer 1).............................................. 135
Data Link Layer (Layer 2)............................................ 136
Network Layer (Layer 3).............................................. 136
Transport Layer (Layer 4)............................................. 137
Session Layer (Layer 5).............................................. 138
Presentation Layer (Layer 6)........................................ 138
Application Layer (Layer 7).......................................... 138
OSI Model Summary................................................... 139
Identifying the OSI Layers at Which Various Network
Components Operate................................................................ 140
Connectionless and Connection-Oriented Protocols................... 140
Introduction to Protocols.......................................................... 141
Internet Protocol (IP)................................................... 142
Transmission Control Protocol (TCP)............................ 142
User Datagram Protocol (UDP).................................... 143
File Transfer Protocol (FTP)......................................... 144
Secure File Transfer Protocol (SFTP)............................ 146
Trivial File Transfer Protocol (TFTP).............................. 146
Simple Mail Transfer Protocol (SMTP).......................... 147
Hypertext Transfer Protocol (HTTP).............................. 147
Hypertext Transfer Protocol Secure (HTTPS)................. 148
Post Office Protocol Version 3/Internet Message Access
Protocol Version 4 (POP3/IMAP4)...................................... 148
Telnet........................................................................ 149
Secure Shell (SSH)..................................................... 150
Internet Control Message Protocol (ICMP)..................... 150
Address Resolution Protocol (ARP)/Reverse Address
Resolution Protocol (RARP)............................................... 151
Network Time Protocol (NTP)....................................... 152
Network News Transfer Protocol (NNTP)....................... 153
Secure Copy Protocol (SCP)....................................... 153
Lightweight Directory Access Protocol (LDAP).............. 154
Internet Group Management Protocol (IGMP)................ 154
Domain Name System (DNS)...................................... 154
Simple Network Management Protocol (SNMP)............. 161
Dynamic Host Configuration Protocol (DHCP)................ 164
Transport Layer Security............................................. 166
Session Initiation Protocol (SIP)/Real-Time Transport
Protocol (RTP).................................................................. 166
TCP/IP Protocol Suite Summary.................................. 168
Review and Test Yourself......................................................... 170
The Facts.................................................................. 171
Key Terms................................................................. 172
Exam Prep Questions................................................. 173
Answers to Exam Prep Questions................................ 175
Need to Know More?............................................................... 176
Chapter 5:
TCP/IP Routing and Addressing........................................................... 177
Introduction............................................................................ 179
IP Addressing............................................................. 179
IPv4........................................................................... 180
IP Address Classes.................................................... 180
Subnet Mask Assignment........................................... 181
Subnetting................................................................. 182
Identifying the Differences Between IPv4 Public and
Private Networks....................................................................... 183
Private Address Ranges.............................................. 184
Classless Interdomain Routing (CIDR).......................... 185
Default Gateways....................................................... 185
IPv4 Address Types.................................................... 187
IPv6 Addressing.......................................................... 187
Comparing IPv4 and IPv6 Addressing............................ 191
Assigning IP Addresses.......................................................... 191
Static Addressing....................................................... 191
Dynamic Addressing................................................... 192
BOOT Protocol (BOOTP)............................................. 194
APIPA....................................................................... 194
Identifying MAC Addresses...................................................... 195
NAT, PAT, and SNAT.............................................................. 196
Network Address Translation (NAT).............................. 196
PAT and SNAT........................................................... 197
TCP/UDP Port Functions......................................................... 198
Managing TCP/IP Routing........................................................ 200
The Default Gateway................................................... 200
Routing Tables........................................................... 200
Static Routing............................................................ 201
Dynamic Routing........................................................ 202
Review and Test Yourself......................................................... 206
The Facts.................................................................. 206
Key Terms................................................................. 207
Exam Prep Questions................................................. 209
Answers to Exam Prep Questions................................ 211
Need to Know More?............................................................... 212
Chapter 6:
WAN Technologies and Internet Access............................................... 213
WAN Technologies................................................................. 214
Switching Methods..................................................... 214
Integrated Services Digital Network (ISDN).................... 217
T-carrier Lines............................................................ 218
SONET/OCx Levels.................................................... 220
X.25 and Frame Relay................................................. 222
Asynchronous Transfer Mode (ATM)............................. 224
Summary of WAN Technologies................................... 224
Internet Access Technologies.................................................. 226
xDSL Internet Access................................................. 226
Cable Internet Access................................................. 229
Broadband Security Considerations.............................. 232
POTS Internet Access................................................ 232
The Public Switched Telephone Network (PSTN)........... 235
Satellite Internet Access............................................. 235
Wireless Internet Access............................................ 237
MPLS........................................................................ 238
Review and Test Yourself......................................................... 239
The Facts.................................................................. 239
Key Terms................................................................. 240
Exam Prep Questions................................................. 241
Answers to Exam Prep Questions................................ 243
Need to Know More?............................................................... 244
Chapter 7:
Wireless Networking........................................................................... 245
Introduction............................................................................ 246
Wireless Access Points.............................................. 247
Working with APs....................................................... 248
Wireless Antennas..................................................... 249
Antenna Ratings......................................................... 250
Antenna Coverage....................................................... 250
Wireless Radio Channels........................................................ 252
Data Rate Versus Throughput...................................... 254
Factors Affecting Wireless Signals........................................... 255
Interference Types...................................................... 255
Spread-Spectrum Technology...................................... 257
Orthogonal Frequency Division Multiplexing................... 258
Beacon Management Frame........................................ 258
802.11 Wireless Standards...................................................... 259
The Magic Behind 802.11n.......................................... 261
Summary of 802.11 Wireless Standards....................... 262
Securing Wireless Networks.................................................... 263
Wired Equivalent Privacy (WEP).................................. 263
Wi-Fi Protected Access (WPA)................................... 264
802.1X....................................................................... 265
Temporal Key Integrity Protocol................................... 266
Establishing Communications Between Wireless Devices.......... 266
Configuring the Wireless Connection........................................ 269
Access Point Coverage........................................................... 271
Wireless Signal Quality........................................................... 273
Wireless Troubleshooting Checklist.......................................... 274
Infrared Wireless Networking.................................................... 275
Bluetooth............................................................................... 276
Review and Test Yourself......................................................... 277
The Facts.................................................................. 277
Key Terms................................................................. 278
Exam Prep Questions................................................. 279
Answers to Exam Prep Questions................................ 281
Need to Know More?............................................................... 282
Chapter 8:
Network Performance Optimization....................................................... 283
Introduction............................................................................ 284
What Is Uptime?..................................................................... 285
The Risks.............................................................................. 287
Fault Tolerance....................................................................... 287
Disk-Level Fault Tolerance........................................... 288
Server and Services Fault Tolerance............................. 293
Link Redundancy........................................................ 295
Using Uninterruptible Power Supplies........................... 296
Disaster Recovery................................................................... 297
Full Backup................................................................ 297
Differential Backup...................................................... 298
Incremental Backup.................................................... 299
Tape Rotations........................................................... 300
Backup Best Practices............................................... 300
Hot and Cold Spares................................................... 301
Hot, Warm, and Cold Sites.......................................... 302
Network Optimization Strategies.............................................. 304
QoS.......................................................................... 304
Traffic Shaping............................................................ 305
Caching Engines........................................................ 306
Working with Command-Line Utilities........................................ 307
Troubleshooting with Diagnostic Utilities....................... 307
The Trace Route Utility (tracert/traceroute).................... 309
ping........................................................................... 312
ARP.......................................................................... 317
The netstat Command................................................. 320
nbtstat....................................................................... 326
The ipconfig Command................................................ 327
ifconfig....................................................................... 329
nslookup.................................................................... 330
dig............................................................................. 331
mtr............................................................................ 333
The host Command..................................................... 333
The route Utility.......................................................... 333
Review and Test Yourself......................................................... 335
The Facts.................................................................. 335
Key Terms................................................................. 337
Exam Prep Questions................................................. 338
Answers to Exam Prep Questions................................ 341
Need to Know More?............................................................... 342
Chapter 9:
Network Security................................................................................ 343
Introduction............................................................................ 345
Firewalls................................................................................ 345
Stateful and Stateless Firewalls................................... 347
Packet-Filtering Firewalls............................................ 348
Circuit-Level Firewalls.................................................. 349
Application Layer Firewalls.......................................... 349
Comparing Firewall Types............................................ 349
Firewall Wrap-up......................................................... 350
Demilitarized Zones (Perimeter Network)....................... 350
Other Security Devices............................................................ 351
Honeypots and Honeynets........................................... 353
Access Control Overview......................................................... 354
Mandatory Access Control (MAC)................................ 354
Discretionary Access Control (DAC)............................. 354
Rule-Based Access Control (RBAC)............................. 355
Role-Based Access Control (RoBAC)........................... 356
MAC Filtering............................................................. 356
TCP/IP Filtering.......................................................... 357
Tunneling and Encryption........................................................ 358
Point-to-Point Tunneling Protocol (PPTP)...................... 359
Layer 2 Tunneling Protocol (L2TP)................................ 359
IPSec........................................................................ 361
Remote-Access Protocols and Services................................... 362
Remote Access Service (RAS).................................... 362
SLIP.......................................................................... 363
PPP.......................................................................... 364
PPPoE...................................................................... 365
Remote-Control Protocols............................................ 365
Authentication, Authorization, and Accounting (AAA)................. 366
Passwords and Password Policies............................... 369
Kerberos Authentication.............................................. 371
Public Key Infrastructure............................................. 373
RADIUS and TACACS+............................................... 376
Remote Authentication Protocols............................................. 377
Physical Security................................................................... 378
Server Room Access.................................................. 379
Secured Versus Unsecured Protocols...................................... 381
Managing Common Security Threats........................................ 382
More on Viruses......................................................... 383
More on Worms and Trojan Horses.............................. 384
Denial of Service and Distributed Denial of Service Attacks 385
Other Common Attacks............................................... 386
An Ounce of Prevention............................................... 388
Review and Test Yourself......................................................... 390
The Facts.................................................................. 390
Key Terms................................................................. 391
Exam Prep Questions................................................. 392
Answers to Exam Prep Questions................................ 394
Need to Know More?............................................................... 395
Chapter 10:
Network Management Tools and Documentation.................................... 397
Introduction............................................................................ 398
Documentation Management................................................... 399
Wiring Schematics..................................................... 401
Physical and Logical Network Diagrams....................... 404
Baselines................................................................... 407
Policies, Procedures, Configurations, and Regulations... 409
Monitoring Network Performance.............................................. 413
Common Reasons to Monitor Networks........................ 413
Packet Sniffers........................................................... 415
Throughput Testing..................................................... 415
Port Scanners............................................................ 417
Network Performance, Load, and Stress Testing............ 420
Tracking Event Logs.................................................... 422
Networking Tools.................................................................... 426
Wire Crimpers, Strippers, and Snips............................. 427
Voltage Event Recorder............................................... 428
Temperature Monitors................................................. 429
Toner Probes.............................................................. 430
Protocol Analyzer....................................................... 431
Media/Cable Testers................................................... 432
TDR and OTDR........................................................... 432
Multimeter.................................................................. 433
Network Qualification Tester........................................ 434
Butt Set..................................................................... 434
Wireless Detection..................................................... 434
Review and Test Yourself......................................................... 435
The Facts.................................................................. 435
Key Terms................................................................. 436
Exam Prep Questions................................................. 437
Answers to Exam Questions....................................... 440
Need to Know More?............................................................... 441
Chapter 11:
Troubleshooting and Supporting the Network......................................... 443
Introduction............................................................................ 444
Troubleshooting Steps and Procedures..................................... 445
Information Gathering: Identify Symptoms and Problems 445
Identify the Affected Areas of the Network..................... 446
Determine if Anything Has Changed............................. 446
Establish the Most Probable Cause.............................. 447
Determine if Escalation Is Necessary........................... 447
Create an Action Plan and Solution Identifying Potential
Effects............................................................................. 448
Implement and Test the Solution.................................. 449
Identify the Results and Effects of the Solution.............. 450
Document the Solution and the Entire Process.............. 450
Troubleshooting the Network.................................................... 451
Troubleshooting Wiring................................................ 451
Wiring Issues............................................................. 453
Troubleshooting Infrastructure Hardware........................ 455
Configuring and Troubleshooting Client Connectivity....... 457
Troubleshooting an Incorrect VLAN............................... 462
Topology Errors...................................................................... 463
Star Topology............................................................. 464
Ring Topology............................................................ 465
Bus Network Errors..................................................... 467
Mesh Network Errors.................................................. 468
Issue Escalation..................................................................... 469
Review and Test Yourself......................................................... 471
The Facts.................................................................. 471
Key Terms................................................................. 472
Exam Prep Questions................................................. 473
Answers to Exam Prep Questions................................ 476
Need to Know More?............................................................... 477
Practice Exam 1................................................................................. 479
Answers to Practice Exam 1............................................................... 499
Answers at a Glance............................................................... 499
Answers and Explanations...................................................... 500
Practice Exam 2................................................................................. 515
Answers to Practice Exam 2............................................................... 533
Answers at a Glance............................................................... 533
Answers and Explanations...................................................... 534
Glossary............................................................................................ 553
TOC, 2/13/09, 9780789737960
