Description
Book SynopsisTable of ContentsIntroduction xxxi
Assessment Test xli
Chapter 1 Introduction to Networks 1
First Things First: What’s a Network? 3
The Local Area Network 4
Common Network Components 6
Metropolitan Area Network 9
Wide Area Network 9
Personal Area Network 10
Campus Area Network 10
Storage Area Network 10
Software-Defined Wide Area Network 11
Multiprotocol Label Switching 11
Multipoint Generic Routing Encapsulation 12
Network Architecture: Peer-to-Peer or Client-Server? 12
Physical Network Topologies 14
Bus Topology 14
Star Topology 15
Ring Topology 17
Mesh Topology 17
Point-to-Point Topology 18
Point-to-Multipoint Topology 19
Hybrid Topology 20
Topology Selection, Backbones, and Segments 21
Selecting the Right Topology 22
The Network Backbone 22
Network Segments 23
Service-Related Entry Points 23
Service Provider Links 23
Virtual Networking 24
Summary 24
Exam Essentials 25
Written Lab 25
Review Questions 26
Chapter 2 The Open Systems Interconnection Specifications 31
Internetworking Models 32
The Layered Approach 33
Advantages of Reference Models 33
The OSI Reference Model 34
The Application Layer 36
The Presentation Layer 37
The Session Layer 37
The Transport Layer 37
The Network Layer 43
The Data Link Layer 46
The Physical Layer 48
Introduction to Encapsulation 49
Modulation Techniques 50
Summary 51
Exam Essentials 51
Written Lab 52
Review Questions 53
Chapter 3 Networking Connectors and Wiring Standards 57
Physical Media 59
Coaxial Cable 60
Twisted-Pair Cable 62
Twinaxial Cable 62
Fiber-Optic Cable 66
Transceivers 71
Media Converters 72
Serial Cables 74
Cable Properties 76
Transmission Speeds 76
Distance 76
Duplex 77
Noise Immunity (Security, EMI) 77
Frequency 77
Wiring Standards 78
T568A vs. T568B 78
Straight-Through Cable 80
Crossover Cable 81
Rolled/Rollover Cable 83
T1 Crossover Cable 83
Installing Wiring Distributions 85
MDF/IDF 85
Summary 87
Exam Essentials 88
Written Lab 88
Review Questions 89
Chapter 4 The Current Ethernet Specifications 93
Network Basics 94
Ethernet Basics 96
Collision Domain 96
Broadcast Domain 97
CSMA/CD 97
Broadband/Baseband 99
Bit Rates vs. Baud Rate 99
Wavelength 99
Half-and Full-Duplex Ethernet 100
Ethernet at the Data Link Layer 102
Binary to Decimal and Hexadecimal Conversion 102
Ethernet Addressing 106
Ethernet Frames 107
Ethernet at the Physical Layer 109
Ethernet over Other Standards (IEEE 1905.1-2013) 115
Ethernet over Power Line 115
Ethernet over HDMI 117
Bidirectional Wavelength-Division Multiplexing (WDM) 117
Course Wavelength-Division Multiplexing (CWDM) 117
Dense Wavelength-Division Multiplexing (DWDM) 117
Summary 118
Exam Essentials 119
Written Lab 119
Review Questions 124
Chapter 5 Networking Devices 129
Common Network Connectivity Devices 132
Network Interface Card 133
Hub 135
Bridge 135
Switch 136
Router 137
Firewall 141
IDS/IPS 142
HIDS 142
Access Point 142
Wireless Range Extender 143
Wireless LAN Controller 143
Load Balancer 144
Contention Methods 144
Dynamic Host Configuration Protocol Server 147
IPAM 152
Other Specialized Devices 152
Multilayer Switch 153
Domain Name Service Server 153
Network Time Protocol 160
Proxy Server 160
Encryption and Content Filtering 162
Analog Modem 163
Packet Shaper 164
VPN Concentrator/Headend 164
Media Converter 165
VoIP PBX 165
VoIP Endpoint 166
NGFW/Layer 7 Firewall 166
VoIP Gateway 166
Cable Modem 166
DSL Modem 166
Networked Devices 167
VoIP Phones 167
Printers 167
Physical Access Control Devices 167
Cameras 167
Heating Ventilation, and Air Conditioning (HVAC) Sensors 167
Internet of Things (IoT) 168
Industrial Control Systems 168
Planning and Implementing a Basic SOHO Network Using Network Segmentation 168
Determining Requirements 169
Switches and Bridges at the Data Link Layer 175
Hubs at the Physical Layer 177
Environmental Considerations 178
Summary 178
Exam Essentials 179
Written Lab 180
Review Questions 181
Chapter 6 Introduction to the Internet Protocol 185
Introducing TCP/IP 188
A Brief History of TCP/IP 188
TCP/IP and the DoD Model 189
The Process/Application Layer Protocols 191
The Host-to-Host Layer Protocols 204
The Internet Layer Protocols 210
Data Encapsulation 220
Summary 224
Exam Essentials 224
Written Lab 225
Review Questions 226
Chapter 7 IP Addressing 231
IP Terminology 233
The Hierarchical IP Addressing Scheme 234
Network Addressing 235
Private IP Addresses (RFC 1918) 239
IPv4 Address Types 241
Layer 2 Broadcasts 242
Layer 3 Broadcasts 242
Unicast Address 243
Multicast Address (Class D) 243
Internet Protocol Version 6 (IPv6) 243
Why Do We Need IPv6? 244
The Benefits of and Uses for IPv6 244
IPv6 Addressing and Expressions 246
Shortened Expression 246
Address Types 247
Special Addresses 248
Stateless Address Autoconfiguration (SLAAC) 249
DHCPv6 (Stateful) 251
Migrating to IPv6 251
Summary 253
Exam Essentials 254
Written Labs 255
Written Lab 7.1 255
Written Lab 7.2 255
Review Questions 257
Chapter 8 IP Subnetting, Troubleshooting IP, and Introduction to NAT 261
Subnetting Basics 263
How to Create Subnets 264
Subnet Masks 265
Classless Inter-Domain Routing (CIDR) 266
Subnetting Class C Addresses 268
Subnetting Class B Addresses 278
Troubleshooting IP Addressing 286
Determining IP Address Problems 289
Introduction to Network Address Translation (NAT) 294
Types of Network Address Translation 295
NAT Names 295
How NAT Works 296
Summary 298
Exam Essentials 298
Written Lab 299
Review Questions 300
Chapter 9 Introduction to IP Routing 305
Routing Basics 306
The IP Routing Process 309
Testing Your IP Routing Understanding 315
Static and Dynamic Routing 316
Summary 319
Exam Essentials 319
Written Lab 320
Review Questions 321
Chapter 10 Routing Protocols 325
Routing Protocol Basics 326
Administrative Distances 327
Classes of Routing Protocols 329
Distance-Vector Routing Protocols 330
Routing Information Protocol (RIP) 332
RIP Version 2 (RIPv2) 332
VLSMs and Discontiguous Networks 333
EIGRP 336
Border Gateway Protocol (BGP) 338
Link-State Routing Protocols 340
Open Shortest Path First (OSPF) 340
Intermediate System-to-Intermediate System (IS-IS) 343
High Availability 344
Hot Standby Router Protocol (HSRP) 346
Virtual Router Redundancy Protocol 350
Advanced IPv6 Concepts 351
Router Advertisement 351
Neighbor Discovery Protocol 353
Tunneling 354
Dual Stack 357
IPv6 Routing Protocols 357
RIPng 358
EIGRPv6 358
OSPFv3 359
Summary 359
Exam Essentials 359
Written Lab 360
Review Questions 361
Chapter 11 Switching and Virtual LANs 365
Networking Before Layer 2 Switching 367
Switching Services 370
Limitations of Layer 2 Switching 371
Bridging vs. LAN Switching 372
Three Switch Functions at Layer 2 372
Distributed Switching 378
Spanning Tree Protocol 378
Spanning Tree Port States 379
STP Convergence 380
Rapid Spanning Tree Protocol 802.1w 381
Virtual LANs 382
VLAN Basics 383
Quality of Service 386
VLAN Memberships 387
Static VLANs 387
Dynamic VLANs 388
Identifying VLANs 388
VLAN Identification Methods 390
VLAN Trunking Protocol 392
VTP Modes of Operation 393
Do We Really Need to Put an IP Address on a Switch? 394
Switch Port Protection 396
Port Bonding 399
Device Hardening 401
Two Additional Advanced Features of Switches 401
Power over Ethernet (802.3af, 802.3at) 401
Port Mirroring/Spanning (SPAN/RSPAN) 404
Summary 405
Exam Essentials 406
Written Lab 406
Review Questions 408
Chapter 12 Wireless Networking 413
Introduction to Wireless Technology 415
Cellular Technologies 418
The 802.11 Standards (Regulatory Impacts) 419
2.4 GHz (802.11b) 421
2.4 GHz (802.11g) 422
5 GHz (802.11a) 423
5 GHz (802.11h) 424
2.4 GHz/5 GHz (802.11n) 425
5 GHz (802.11ac) 426
WiFi 6 (802.11ax) 426
Comparing 802.11 Standards 427
Range and Speed Comparisons 428
Wireless Network Components 428
Wireless Access Points 429
Wireless Network Interface Card 430
Wireless Antennas 431
Installing a Wireless Network 432
Ad Hoc Mode: Independent Basic Service Set 432
Infrastructure Mode: Basic Service Set 433
Wireless Controllers 434
Mobile Hot Spots 436
Signal Degradation 438
Other Network Infrastructure Implementations 438
Technologies That Facilitate the Internet of Things (IoT) 440
Installing and Configuring WLAN Hardware 441
Site Survey 447
Providing Capacity 448
Multiple Floors 449
Location-Based WLAN 450
Site Survey Tools 450
Wireless Security 451
Wireless Threats 451
Open Access 455
Service Set Identifiers, Wired Equivalent Privacy, and Media Access Control Address Authentication 455
Remote Authentication Dial-In User Service (802.1X) 457
Temporal Key Integrity Protocol 458
Wi-Fi Protected Access or WPA2 Pre-Shared Key 459
Summary 462
Exam Essentials 462
Written Lab 464
Review Questions 465
Chapter 13 Using Statistics and Sensors to Ensure Network Availability 469
Performance Metrics/Sensors 471
Device/Chassis 471
Network Metrics 473
SNMP 474
Traps 475
Object Identifiers (OIDs) 476
Management Information Bases (MIBs) 476
Network Device Logs 476
Log Reviews 476
Logging Levels/Severity Levels 480
Interface Statistics/Status 482
Link State (Up/Down) 482
Speed/Duplex 483
Send/Receive Traffic 484
Cyclic Redundancy Checks (CRCs) 485
Protocol Packet and Byte Counts 486
Interface Errors or Alerts 486
CRC Errors 487
Giants and Runts 488
Encapsulation Errors 488
Environmental Factors and Sensors 489
Temperature 489
Humidity 489
Electrical 490
Flooding 495
Baselines 495
NetFlow Data 496
NetFlow Overview and Flows 496
Uptime/Downtime 498
Summary 498
Exam Essentials 498
Written Lab 499
Review Questions 501
Chapter 14 Organizational Documents and Policies 505
Plans and Procedures 507
Change Management 508
Incident Response Plan 510
Disaster Recovery Plan 510
Business Continuity Plan 510
System Life Cycle 511
Standard Operating Procedures 511
Hardening and Security Policies 511
Acceptable Use Policy 512
Password Policy 512
Bring Your Own Device (BYOD) Policy 513
Remote Access Policy 513
Onboarding and Offboarding Policy 513
Security Policy 514
Data Loss Prevention 519
Common Documentation 519
Physical Network Diagram 520
Logical Network Diagram 524
Wiring Diagram 525
Site Survey Report 526
Audit and Assessment Report 526
Baseline Configurations 527
Common Agreements 528
Nondisclosure Agreement (NDA) 528
Service-Level Agreement (SLA) 529
Memorandum of Understanding (MOU) 529
Summary 529
Exam Essentials 529
Written Lab 530
Review Questions 531
Chapter 15 High Availability and Disaster Recovery 533
Load Balancing 535
Multipathing 536
Network Interface Card (NIC) Teaming 537
Redundant Hardware/Clusters 538
Switches 538
Routers 540
Firewalls 542
Facilities and Infrastructure Support 542
Uninterruptible Power Supply (UPS) 542
Power Distribution Units (PDUs) 543
Generator 543
HVAC 544
Fire Suppression 544
Redundancy and High Availability (HA) Concepts 545
Recovery Sites 545
Cold Site 545
Warm Site 545
Hot Site 546
Cloud Site 546
Active/Active vs. Active/Passive 546
Mean Time to Repair (MTTR) 553
Mean Time Between Failure (MTBF) 554
Recovery Time Objective (RTO) 554
Recovery Point Objective (RPO) 554
Network Device Backup/Restore 554
State/Configuration 554
Summary 555
Exam Essentials 555
Written Lab 556
Review Questions 557
Chapter 16 Common Security Concepts 559
Confidentiality, Integrity, and Availability (CIA) 561
Confidentiality 561
Integrity 561
Availability 562
Threats 562
Internal 562
External 562
Vulnerabilities 562
Common Vulnerabilities and Exposures (CVE) 563
Zero-Day 563
Exploits 563
Least Privilege 563
Role-Based
Access 564
Zero Trust 564
Defense in Depth 564
Network Segmentation Enforcement 564
Screened Subnet (aka Demilitarized Zone) 565
Separation of Duties 565
Network Access Control 566
Honeypot 567
Authentication Methods 567
Multifactor 567
Authentication, Authorization, and Accounting (AAA) 568
Remote Authentication Dial-In User Service (RADIUS) 568
Terminal Access Controller Access Control System Plus (TACACS+) 568
Single Sign-On (SSO) 570
LDAP 570
Kerberos 570
Local Authentication 571
802.1X 571
Extensible Authentication Protocol (EAP) 572
Security Risk Assessments 573
Threat Assessment 573
Vulnerability Assessment 574
Penetration Testing 575
Business Risk Assessments 575
Security Information and Event Management (SIEM) 576
Notifications 576
Summary 576
Exam Essentials 577
Written Lab 577
Review Questions 578
Chapter 17 Common Types of Attacks 581
Technology-Based Attacks 582
Denial of Service (DoS)/Distributed Denial of Service (DDoS) 583
On-Path Attack (Previously Known as Man-in-the-Middle Attack) 588
DNS Poisoning 589
VLAN Hopping 589
ARP Spoofing 590
Rogue DHCP 590
Rogue Access Point (AP) 591
Evil Twin 592
Ransomware 593
Password Attacks 593
MAC Spoofing 594
IP Spoofing 594
Deauthentication 594
Malware 594
Human and Environmental 598
Social Engineering 598
Phishing 599
Environmental 599
Summary 600
Exam Essentials 600
Written Lab 601
Review Questions 602
Chapter 18 Network Hardening Techniques 605
Best Practices 607
Secure SNMP 608
Router Advertisement (RA) Guard 608
Port Security 608
Dynamic ARP Inspection 609
Control Plane Policing 609
Private VLANs 609
Disable Unneeded Switchports 610
Disable Unneeded Network Services 610
Change Default Passwords 610
Password Complexity/Length 610
Enable DHCP Snooping 613
Change Default VLAN 613
Patch and Firmware Management 614
Access Control List 615
Role-Based Access 616
Firewall Rules 617
Wireless Security 618
MAC Filtering 618
Antenna Placement 618
Power Levels 619
Wireless Client Isolation 619
Guest Network Isolation 620
Preshared Keys (PSKs) 620
EAP 620
Geofencing 620
Captive Portal 621
IoT Access Considerations 621
Summary 621
Exam Essentials 621
Written Lab 622
Review Questions 623
Chapter 19 Remote Access Security 625
Site-to-Site VPN 626
Client-to-Site VPN 626
Clientless VPN 627
Split Tunnel vs. Full Tunnel 628
Remote Desktop Connection 628
Remote Desktop Gateway 629
SSH 630
Virtual Network Computing (VNC) 630
Virtual Desktop 631
Authentication and Authorization Considerations 631
In-Band vs. Out-of-Band Management 631
Summary 632
Exam Essentials 632
Written Lab 632
Review Questions 634
Chapter 20 Physical Security 637
Detection Methods 639
Cameras 639
Motion Detection 640
Asset Tags 641
Tamper Detection 641
Prevention Methods 642
Employee Training 642
Access Control Hardware 643
Locking Racks 643
Locking Cabinets 644
Access Control Vestibule (Previously Known as a Mantrap) 644
Smart Lockers 645
Asset Disposal 646
Factory Reset/Wipe Configuration 646
Sanitize Devices for Disposal 646
Summary 647
Exam Essentials 647
Written Lab 648
Review Questions 649
Chapter 21 Data Center Architecture and Cloud Concepts 651
Data Center Network Architectures 654
Access/Edge Layer 654
Distribution Layer 655
Core Layer 655
Software-Defined Networking 655
Application Layer 656
Control Layer 656
Infrastructure Layer 656
Management Plane 656
Spine-Leaf–Based Two-Tier Networks 657
Top-of-Rack Switching 658
Backbone 658
Traffic Flows 658
North-South 659
East-West 659
Branch Office vs. On-premises Data Center vs. Colocation 660
Cloud Computing and Its Effect on the Enterprise Network 661
Service Models 663
Overview of Network Programmability in Enterprise Network 665
Software-Defined Networking 666
Application Programming Interfaces (APIs) 666
Southbound APIs 667
Northbound APIs 669
Managing Network Documentation 670
Using SNMP 670
Schematics and Diagrams 671
Network Monitoring 676
Baselines 676
Processes 676
Onboarding and Offboarding of Mobile Devices 677
NAC 677
Policies, Procedures, and Regulations 677
Safety Practices 681
Implementing Network Segmentation 686
Network Optimization 689
Reasons to Optimize Your Network’s Performance 689
How to Optimize Performance 691
Unified Communications 694
Traffic Shaping 694
Load Balancing 695
High Availability 695
Caching Engines 695
Fault Tolerance 696
Archives/Backups 696
Common Address Redundancy Protocol 697
Virtual Networking 697
Locating and Installing Equipment 708
Change Management Procedures 715
Summary 717
Exam Essentials 719
Written Lab 720
Review Questions 721
Chapter 22 Ensuring Network Availability 725
Performance Metrics/Sensors 727
Network Metrics 728
SNMP 729
Network Device Logs 731
Interface Statistics/Status 733
Interface Errors 734
Environmental Factors and Sensors 735
Baseline 736
NetFlow 737
Uptime 738
Downtime 738
Summary 739
Exam Essentials 739
Written Lab 740
Review Questions 741
Chapter 23 Cable Connectivity Issues and Tools 745
Specifications and Limitations 747
Cable Considerations 747
Cable Applications 748
Common Issues 749
Identifying Hardware Tools 751
Cable Testers 752
Protocol Analyzer 755
Certifiers 755
Time-Domain Reflectometer 756
Optical Time-Domain Reflectometer 756
Multimeter 757
Spectrum Analyzer 758
Toner Generator (Probe) 759
Tap 760
Metrics 760
Butt Set 761
Punch-Down Tool 761
Cable Snips/Cutters 763
Voltage Event Recorder (Power) 763
Fiber Light Meter 764
Fiber Fusion Splicer 764
Summary 765
Exam Essentials 765
Written Lab 766
Review Questions 767
Chapter 24 Network Troubleshooting Methodology 771
Narrowing Down the Problem 775
Did You Check the Super Simple Stuff? 776
Is Hardware or Software Causing the Problem? 780
Is It a Workstation or a Server Problem? 781
Which Segments of the Network Are Affected? 781
Is It Bad Cabling? 782
Troubleshooting Steps 791
Step 1: Identify the Problem 792
Step 2: Establish a Theory of Probable Cause 796
Step 3: Test the Theory to Determine Cause 806
Step 4: Establish a Plan of Action to Resolve the Problem and Identify Potential Effects 809
Step 5: Implement the Solution or Escalate as Necessary 810
Step 6: Verify Full System Functionality, and If Applicable, Implement Preventative Measures 813
Step 7: Document Findings, Actions, Outcomes, and Lessons Learned 814
Troubleshooting Tips 815
Don’t Overlook the Small Stuff 815
Prioritize Your Problems 815
Check the Software Configuration 816
Don’t Overlook Physical Conditions 817
Don’t Overlook Cable Problems 817
Check for Viruses 818
Summary 818
Exam Essentials 818
Written Lab 819
Review Questions 821
Chapter 25 Network Software Tools and Commands 825
Software Tools 827
Wi-Fi Analyzers 827
Protocol Analyzer/Packet Capture 828
Bandwidth Speed Testers 829
Port Scanners 830
NetFlow Analyzers 830
Trivial File Transfer Protocol (TFTP) Server 831
Connectivity Software 831
IP Scanner 832
Using traceroute 833
Using ipconfig, ifconfig, and ip 836
Using the ipconfig Utility 836
Using the ifconfig Utility 840
Using the ip Utility 840
Using the iptables Utility 841
Examples of iptables 841
Using the ping Utility 841
Using the Address Resolution Protocol 845
The Windows ARP Table 845
Using the arp Utility 846
Using the nslookup Utility 849
Resolving Names with the Hosts File 850
Using the Mtr Command (pathping) 852
Using the Nmap Utility 853
Using the route Command 854
Using the route Command Options 854
Some Examples of the route Command 857
Using the nbtstat Utility 857
The –a Switch 858
The –A Switch 860
The –c Switch 860
The –n Switch 860
The –r Switch 861
The –R Switch 862
The –S Switch 862
The –s Switch 863
Using the netstat Utility 863
The –a Switch 866
The –e Switch 866
The –r Switch 867
The –s Switch 867
The –p Switch 868
The –n Switch 869
Using tcpdump 871
Examples of Using tcpdump 871
Using the File Transfer Protocol 871
Starting FTP and Logging In to an FTP Server 872
Downloading Files 874
Uploading Files 876
Using the Telnet Utility 876
How to Enable Telnet in Windows 877
Don’t Use Telnet, Use Secure Shell 878
Summary 878
Exam Essentials 879
Written Lab 880
Review Questions 881
Appendix A Answers to Written Labs 887
Chapter 1: Introduction to Networks 888
Chapter 2: The Open Systems Interconnection Specifications 888
Chapter 3: Networking Connectors and Wiring Standards 889
Chapter 4: The Current Ethernet Specifications 889
Chapter 5: Networking Devices 891
Chapter 6: Introduction to the Internet Protocol 892
Chapter 7: IP Addressing 893
Written Lab 7.1 893
Written Lab 7.2 893
Chapter 8: IP Subnetting, Troubleshooting IP, and Introduction to NAT 894
Chapter 9: Introduction to IP Routing 895
Chapter 10: Routing Protocols 895
Chapter 11: Switching and Virtual LANs 895
Chapter 12: Wireless Networking 896
Chapter 13: Using Statistics and Sensors to Ensure Network Availability 896
Chapter 14: Organizational Documents and Policies 897
Chapter 15: High Availability and Disaster Recovery 898
Chapter 16: Common Security Concepts 898
Chapter 17: Common Types of Attacks 899
Chapter 18: Network Hardening Techniques 899
Chapter 19: Remote Access Security 900
Chapter 20: Physical Security 900
Chapter 21: Data Center Architecture and Cloud Concepts 901
Chapter 22: Ensuring Network Availability 901
Chapter 23: Cable Connectivity Issues and Tools 902
Chapter 24: Network Troubleshooting Methodology 902
Chapter 25: Network Software Tools and Commands 903
Appendix B Answers to Review Questions 905
Chapter 1: Introduction to Networks 906
Chapter 2: The Open Systems Interconnection Specifications 907
Chapter 3: Networking Connectors and Wiring Standards 909
Chapter 4: The Current Ethernet Specifications 910
Chapter 5: Networking Devices 911
Chapter 6: Introduction to the Internet Protocol 913
Chapter 7: IP Addressing 914
Chapter 8: IP Subnetting, Troubleshooting IP, and Introduction to NAT 916
Chapter 9: Introduction to IP Routing 918
Chapter 10: Routing Protocols 919
Chapter 11: Switching and Virtual LANs 921
Chapter 12: Wireless Networking 922
Chapter 13: Using Statistics and Sensors to Ensure Network Availability 924
Chapter 14: Organizational Documents and Policies 925
Chapter 15: High Availability and Disaster Recovery 926
Chapter 16: Common Security Concepts 927
Chapter 17: Common Types of Attacks 927
Chapter 18: Network Hardening Techniques 928
Chapter 19: Remote Access Security 929
Chapter 20: Physical Security 930
Chapter 21: Data Center Architecture and Cloud Concepts 931
Chapter 22: Ensuring Network Availability 933
Chapter 23: Cable Connectivity Issues and Tools 934
Chapter 24: Network Troubleshooting Methodology 935
Chapter 25: Network Software Tools and Commands 937
Appendix C Subnetting Class A 939
Subnetting Practice Examples: Class A Addresses 940
Practice Example #1A: 255.255.0.0 (/16) 941
Practice Example #2A: 255.255.240.0 (/20) 941
Practice Example #3A: 255.255.255.192 (/26) 942
Subnetting in Your Head: Class A Addresses 942
Written Lab 1 943
Written Lab 2 944
Answers to Written Lab 1 944
Answers to Written Lab 2 945
Index 947
