* (asterisk), 453
/8 networks, subnetting, 372–373, 391
10BASE-T, 143
/16 networks, subnetting, 367–370, 391
100BASE-TX, 143
A records, 524
AAA (authentication, authorization, and accounting), 555
AAA (authentication, authorization, and accounting)x, 645
AAAA records, 524
access, IOS. See Cisco IOS
brute-force, 646
definition of, 645
DoS (denial-of-service), 551–552
man-in-the-middle attack, 549
password attacks, 548
port redirection, 549
access control lists (ACLs), 35
access methods, definition of, 645
access points (APs), 138, 166, 645
access technologies, 17–20, 92
small office and home offices, 17–19
summary of, 38
ACK (Acknowledgement), 472, 484–486, 488
ACK (Acknowledgment), 645
Acknowledgment (ACK), 645
ACLs (access control lists), 35
address conservation, IPv4, 381–383
address resolution, IPv6 ND (Neighbor Discovery), 311
Address Resolution Protocol. See ARP (Address Resolution Protocol)
addresses
ARP (Address Resolution Protocol)
examining with Packet Tracer, 309
maps, 303
replies, 305
requests, 304
role in remote communications, 305–306
summary of, 313
devices on same network, 123
IP. See IP (Internet Protocol) addresses
MAC (media access control), 239–248
destinations on remote network, 299–301
destinations on same network, 298–299
hexadecimal number system, 240–241
summary of, 313
types of, 121
adjacency tables, 645
ADVERTISE messages, 529
adware, 33
AfriNIC (African Network Information Centre), 358
alternating current, 645
American National Standards Institute (ANSI), 141, 209
American Registry for Internet Numbers (ARIN), 358
American Standard Code for Information Interchange (ASCII), 645
analog telephones, 645
ANSI (American National Standards Institute), 141, 209
Anti-Spam Research Group (ASRG), 109
antispyware, 34
antivirus software, 34
APIPA (Automatic Private IP Addressing), 357, 619
APNIC (Asia Pacific Network Information Centre), 358
AppleTalk, 99
application filtering, 557
application layer. See also specific protocols
IMAP (Internet Message Access Protocol), 521
POP (Post Office Protocol), 520
SMTP (Simple Mail Transfer Protocol), 519–520
summary of, 534
file sharing services, 530–533
FTP (File Transfer Protocol), 530
SMB (Server Message Block), 531–533
functions of, 508
IP addressing services, 521–530
DHCP (Dynamic Host Configuration Protocol), 527–529
DNS (Domain Name System), 522–525
summary of, 535
peer-to-peer applications, 513–515
peer-to-peer networks, 512–513, 534
services in, 579
summary of, 534
HTML (Hypertext Markup Language), 515–517
HTTP (Hypertext Transfer Protocol), 516–518
summary of, 534
applications
small business networks
voice/video applications, 582
summary of, 624
APs (access points), 138, 166, 645
architecture, network, 23
fault tolerance, 24
QoS (quality of service), 25–26
ARCNET, 217
ARIN (American Registry for Internet Numbers), 358
ARP (Address Resolution Protocol), 103, 245, 360
definition of, 103, 245, 301–302, 360, 645
examining with Packet Tracer, 309
maps, 303
replies, 305
requests, 304
role in remote communications, 305–306
summary of, 313
tables
removing entries from, 306–307
arp -a command, 307
ASCII (American Standard Code for Information Interchange), 645
Asia Pacific Network Information Centre (APNIC), 358
ASRG (Anti-Spam Research Group), 109
assigned multicast, 646
asterisk (*), 453
asymmetric switching, 646
ATM (Asynchronous Transfer Mode), 225
brute-force, 646
DoS (denial-of-service), 551–552
man-in-the-middle attack, 549
password attacks, 548
port redirection, 549
viruses, 546
AAA (authentication, authorization, and accounting), 555
defense-in-depth approach, 553
endpoint security, 558
summary of, 565
updates and patches, 554
summary of, 565
attenuation, signal, 147
.au domain, 525
authentication, authorization, and accounting (AAA), 555, 645
automatic medium-dependent interface crossover (auto-MDIX), 259–260, 646
bandwidth, 234
definition of, 646
latency, 146
units of, 145
banner motd command, 65–66, 321, 322
best-effort delivery, 272, 468, 646. See also UDP (User Datagram Protocol)
BGP (Border Gateway Protocol), 103
BIA (burned-in address), 243, 647
binary number systems, 176–194
binary game, 193
binary positional notation, 178–180
binary to decimal conversion, 180–181
decimal to binary conversion
binary positional value tables, 182–186
IPv4 addresses, 176–178, 193–194
summary of, 198
binary positional notation, 178–180
binary positional value tables, 182–186
BitTorrent, 514
blocking IPv4 addresses, 356
BOOTP (Bootstrap Protocol), 510, 646
Bootstrap Protocol (BOOTP), 646
Border Gateway Protocol (BGP), 103
bring your own device (BYOD), 28, 646
broadcast domains, segmentation and, 359–362
broadcast MAC (media access control) addresses, 246–247
broadcast transmission, 93
ARP (Address Resolution Protocol), 307–309
definition of, 646
brute-force attacks, 548, 560, 646
burned-in address (BIA), 243, 647
businesses. See small business network management
cable internet connections, 18, 647
cable testers, 647
cabling, copper, 7, 146–152, 168–169
fiber-optic cabling versus, 163–164
rollover cables, 157
STP (shielded twisted pair), 150–151, 662
UTP (unshielded twisted pair), 152–158
crossover, 157
straight-through, 157
copper cabling versus, 163–164
definition of, 652
fiber-optic connectors, 161–162
industry applications of, 160
multimode fiber, 160
single-mode fiber, 159
summary of, 169
CAM (content addressable memory) table, 649
Canadian Standards Association (CSA), 141
Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA), 165–166, 216, 219–220, 647
Carrier Sense Multiple Access/Collision Detect (CSMA/CD), 216, 217–219, 647
categories, UTP cabling, 154
CCNA (Cisco Certified Network Associate) certification, 35–36
CDP (Cisco Discovery Protocol), 609–610
CEF (Cisco Express Forwarding), 647
CENELEC (European Committee for Electrotechnical Standardization), 141
certifications, CCNA (Cisco Certified Network Associate), 35–36
CFRG (Crypto Forum Research Group), 109
Checksum field
TCP headers, 472
UDP headers, 474
circuit switched systems, 647
Cisco Certified Network Associate (CCNA) certification, 35–36
Cisco Discovery Protocol (CDP), 609–610
Cisco Express Forwarding (CEF), 647
Cisco IOS
GUIs (graphical user interfaces), 47–48
OSs (operating systems), 48–49
summary of, 79
terminal emulation programs, 50–52
basic structure of, 56
hot keys and shortcuts for, 58–60
summary of, 79
definition of, 648
with Packet Tracer, 71
running configuration, altering, 68
small business network management, 573–574, 624
with Syntax Checker, 66
help, 58
IP (Internet Protocol) addresses, 618
automatic configuration for end devices, 76–77
manual configuration for end devices, 75–76
summary of, 80
switch virtual interface configuration, 77–78
verification of, 77
Packet Tracer, 60
summary of, 79
Tera Term, 60
verifying connectivity of, 78, 80
Cisco Packet Tracer. See Packet Tracer
Cisco routers. See router configuration
Cisco Webex Teams, 29
Class A addresses, 357
Class B addresses, 357
Class C addresses, 357
Class D addresses, 357
Class E addresses, 357
classful addressing, legacy, 357–358, 648
clients
multicast, 352
UDP (User Datagram Protocol), 495–498
clock command, 60
cloud computing
definition of, 648
impact on daily life, 4
CnC (command-and-control) programs, 551
.co domain, 525
collision fragments, 238
.com domain, 525
command modes, Cisco IOS
command syntax check, 58
command-and-control (CnC) programs, 551
command-line interface (CLI). See specific commands
communications, network. See network communications
communities, definition of, 648
community cloud, 30
configuration. See also verification
Cisco IOS devices, 61–66. See also IP (Internet Protocol) addresses
running configuration, altering, 68
small business network management, 573–574, 624
with Syntax Checker, 66
verifying connectivity of, 78, 80
router connections, 334
with Syntax Checker, 334
default route propagation, 335–336
GUAs (global unicast addresses)
IP (Internet Protocol) addresses
automatic configuration for end devices, 76–77
manual configuration for end devices, 75–76
switch virtual interface configuration, 77–78
IPv4 subnets
DMZ (demilitarized zone), 377
within an octet boundary, 366–367
private versus public address space, 374–377
unused host IPv4 addresses, minimizing, 377–378
VLSM (variable-length subnet masking), 381–387
router configuration, 435
LLAs (link-local addresses)
dual stack addressing, 324–325
summary of, 335
verification commands, 325–330
ARP tables, displaying, 306–307
basic configuration example, 321–323
basic configuration steps, 320–321, 335
dynamic LLAs (link-local addresses) on, 426–427
host/router communications, 223–225
switch and router network build, 336–337
vulnerabilities, 544
configure command, 58
configure terminal command, 54, 62, 321, 324
congestion, definition of, 649
congestion avoidance, 493
connected switches, MAC (media access control) address tables on, 252
connectionless, definition of, 649
connectionless IP (Internet Protocol), 271–272
connection-oriented protocols, 468, 649. See also TCP (Transmission Control Protocol)
connectivity, verification of, 586–596
summary of, 624
connectors
UTP (unshielded twisted pair) cable, 153–156
content addressable memory (CAM) table, 649
contention-based access, 217–220
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance), 216, 219–220
CSMA/CD (Carrier Sense Multiple Access/Collision Detect), 216, 217–219
definition of, 649
contention-based access method, 237
context-sensitive help, 58
Control Bits field (TCP headers), 472
controlled access, 217
converged networks, 20–21, 649
fiber-optic cabling versus, 163–164
rollover cables, 157
STP (shielded twisted pair), 150–151, 662
UTP (unshielded twisted pair), 152–158
crossover, 157
straight-through, 157
summary of, 169
copy running-config startup-config command, 68, 322
core, optical fiber, 649
CRC (cyclic redundancy check), 222–223, 239, 649
crossover UTP cables, 157
Crypto Forum Research Group (CFRG), 109
crypto key generate rsa general-keys modulus command, 561, 562
CSA (Canadian Standards Association), 141
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance), 165–166, 216, 219–220, 647
CSMA/CD (Carrier Sense Multiple Access/Collision Detect), 216, 217–219, 647
custom cloud, 649
cut-through switching, 255–256, 649
cyclic redundancy check (CRC), 222–223, 239, 649
DAD (duplicate address detection), 424, 448
daemons, 650
data link layer addresses, 124, 125, 126–129
devices on same network, 123
Layer 3 logical addresses, 122–123
overview of, 121
summary of, 132
data centers, 650
data confidentiality, 27
de-encapsulation, 120–121, 132
example of, 120
IP (Internet Protocol), 270–271
MAC (media access control) sublayer, 236
PDUs (protocol data units), 118–120, 132
summary of, 132
Data field (Ethernet frames), 239
data flow, 6
data interception and theft, 33
overview of, 221
data link layer
overview of, 221
summary of, 229
definition of, 114
IEEE 802 LAN/MAN sublayers, 206–207
standards, 209
access control methods, 216–217
contention-based access, 216–220
controlled access, 217
full-duplex communication, 215–216, 653
half-duplex communication, 215, 653
LAN (local area network), 213–214
summary of, 228
WAN (wide area network), 211–213
data link sublayers, 235
data networks, definition of, 650
Data Usage tool, 585
datagrams, 118, 463, 468, 494, 650
debug ip icmp command, 615
debug ip packet command, 615
decapsulation. See de-encapsulation
decimal numbers
binary to decimal conversion, 180–181
decimal positional notation, 178–179
decimal to binary conversion
binary positional value tables, 182–186
decimal to hexadecimal conversion, 196
hexadecimal to decimal conversion, 196–197
decoding messages, 89
de-encapsulation, 120–121, 132, 650
default gateways
router connections, 334
with Syntax Checker, 334
definition of, 282
sending frames to, 254
default routes, 650
defense-in-depth approach, 553
delimiting, frame, 207
Deluge, 514
demilitarized zone. See DMZ (demilitarized zone)
denial-of-service (DoS) attacks, 33, 543, 650
description command, 57, 323–324
design, IPv4 structure, 387–389, 392
device address assignment, 389
IPv4 network address planning, 388
with Packet Tracer, 389, 392–393
Destination IPv4 Address field, 276
destination IPv4 addresses, 122, 123, 125, 299
Destination IPv6 Address field, 280
Destination MAC Address field, 238
destination MAC addresses, 124, 126, 243, 299, 301, 305
Destination Port field
TCP headers, 472
UDP headers, 474
destination port numbers, 650
Destination Unreachable messages, 445–446
destinations, definition of, 87
device address assignment, 389
device configuration, 61–66. See also IP (Internet Protocol) addresses
passwords
running configuration, altering, 68
small business network management, 573–574, 624
with Syntax Checker, 66
verifying connectivity of, 78, 80
device identifiers, 422
device security
summary of, 566
unused services, disabling, 563–564
DHCP (Dynamic Host Configuration Protocol)
dynamic addressing in, 527
IP address configuration with, 75, 360
pools, 527
port numbers, 479
servers, 581
SLAAC (stateless address autoconfiguration)
DHCPACK messages, 529
DHCPDISCOVER messages, 528–529
DHCPNAK messages, 529
DHCPREQUEST messages, 529
definition of, 10
physical, 10
dialup internet access, 19
dial-up telephone, 650
DiffServ (DS) field (IPv4), 275
digital cameras, 650
digital subscriber line (DSL), 9, 18
Direct Connect, 514
directed broadcast transmission, 351–352, 651
directly connected networks, 651
disable command, 54
disruption of service, 543
DMZ (demilitarized zone)
definition of, 651
subnetting, 377
DNS (Domain Name System)
hierarchy, 525
nslookup command, 526–527, 530
port numbers, 479
domains
top-level, 525
DoS (denial-of-service) attacks, 33, 543, 551–552, 650
dotted decimal notation
binary to decimal conversion, 180–181
decimal positional notation, 178–179
decimal to binary conversion
binary positional value tables, 182–186
decimal to hexadecimal conversion, 196
hexadecimal to decimal conversion, 196–197
downloads, 512
DS (DiffServe) field (IPv4), 275
DSL (digital subscriber line), 9, 18, 650
dual stack addressing, 324–325, 399–400, 651
duplex multimode LC (Lucent Connector) connectors, 162, 651
duplex operation
definition of, 651
troubleshooting, 617
duplicate address detection (DAD), 424, 448
dynamic addressing, 527
for GUAs (global unicast addresses), 417–425, 437
randomly generated interface IDs, 424–425
SLAAC and stateless DHCPv6, 419–420
for LLAs (link-local addresses), 425–430, 437–438
dynamic LLA creation, 425
dynamic LLA on Cisco routers, 426–427
dynamic LLA on Windows, 425–426
IPv6 address configuration, verification of, 427–430
with Packet Tracer, 430
Dynamic Host Configuration Protocol. See DHCP (Dynamic Host Configuration Protocol)
dynamic routing protocols, 651. See also specific protocols
Echo Request messages, 444–445
eDonkey, 514
EHs (extension headers), 280
EIA (Electronic Industries Alliance), 111
EIGRP (Enhanced Interior Gateway Routing Protocol), 103
electrical threats, 545
electromagnetic interference (EMI), 147, 651
Electronic Industries Alliance (EIA), 111
electronic standards, 111
IMAP (Internet Message Access Protocol), 521
POP (Post Office Protocol), 520
SMTP (Simple Mail Transfer Protocol), 519–520
summary of, 534
EMI (electromagnetic interference), 147, 651
employee network utilization, 584–586
enable command, 54
enable passwords, 651
enable secret, 64, 320, 322, 651
de-encapsulation, 120–121, 132
definition of, 651
example of, 120
IP (Internet Protocol), 270–271
MAC (media access control) sublayer, 236
PDUs (protocol data units), 118–120, 132
summary of, 132
end command, 55
end devices. See hosts
endpoint security, 558
Enhanced Interior Gateway Routing Protocol (EIGRP), 103
enterprise networks, 160
environmental threats, 545
erase startup-config command, 68
error detection, 96, 207, 222–223
escalation, 613
EtherChannel, 651
bandwidths, 234
crossover, 157
encoding, 143
data link sublayers, 235
forwarding methods, 254–255, 262
sending to default gateway, 254
summary of, 261
Gigabit, 323
hubs, 7
MAC (media access control) addresses, 239–248
hexadecimal number system, 240–241
summary of, 261
straight-through, 157
switches
cut-through switching, 255–256, 649
fast-forward switching, 256, 652
fragment-free switching, 256, 652–653
frame forwarding methods on, 254–255
learning and forwarding, 248–249
memory buffering on, 257
store-and-forward switching, 254–255, 664
ETSI (European Telecommunications Standards Institute), 141
EUIs (Extended Unique Identifiers), 422–424
European Committee for Electrotechnical Standardization, 141
European Telecommunications Standards Institute (ETSI), 141
exec-timeout command, 561
Exit and Logout command (Packet Tracer), 22
expandability, small business networks, 573
expectational acknowledgement, 488, 652
Extended Unique Identifiers (EUIs), 422–424, 652
extension headers (EHs), 280
fast-forward switching, 256, 652
FCC (Federal Communications Commission), 141
FCS (Frame Check Sequence) field, 222–223, 239
FDDI (Fiber Distributed Data Interface), 214
Federal Communications Commission (FCC), 141
ff02::1 all-nodes multicast group, 431
ff02::2 all-routers multicast group, 431
FIB (Forwarding Information Base), 652
Fiber Distributed Data Interface (FDDI), 214
fiber-optic cabling, 7, 158–164
copper cabling versus, 163–164
definition of, 652
fiber-optic connectors, 161–162
industry applications of, 160
multimode fiber, 160
single-mode fiber, 159
summary of, 169
fiber-optic connectors, 161–162
fiber-to-the-home (FTTH), 160
fields
TCP headers, 472
UDP headers, 474
file servers, 5
file sharing services, 530–533
FTP (File Transfer Protocol), 530
SMB (Server Message Block), 531–533
File Transfer Protocol (FTP), 101, 511, 581. See also file sharing services
filtering
URLs (uniform resource locators), 557
FIN flag, 486
Finish (FIN) control flag, 484–485
definition of, 652
firmware, 48
flags, 486
flow control, 92, 471, 490–494, 652
Flow Label field (IPv6), 280
form-factor pluggable (SFP) devices, 161
forwarding, 248–249, 254–255, 262, 281–282, 285–286
Forwarding Information Base (FIB), 652
fping command, 547
FQDNs (fully qualified domain names), 522
fragment-free switching, 256, 652–653
Frame Check Sequence (FCS) field, 222–223, 239
Frame Relay, 225
frames
overview of, 221
summary of, 229
delimiting, 207
data link sublayers, 235
forwarding methods, 254–255, 262
sending to default gateway, 254
summary of, 261
MAC (media access control) addresses, 243–244
Freenet, 514
FTP (File Transfer Protocol), 101, 479, 511, 530, 581
definition of, 652
FTPS (FTP Secure), 581
FTTH (fiber-to-the-home), 160
full-duplex communication, 215–216, 617, 653
fully qualified domain names (FQDNs), 522
gateways, default
router connections, 334
with Syntax Checker, 334
definition of, 282
sending frames to, 254
gateways, definition of, 653
Gbps (gigabits per second), 145
GET requests, 516
GIF (Graphics Interchange Format), 509
Gigabit Ethernet, 323
gigabits per second (Gbps), 145
global configuration mode, 53, 653
global routing prefix, 410, 653
global unicast addresses. See GUAs (global unicast addresses)
Gnutella, 514
gping command, 547
graphical user interfaces (GUIs), 47–48, 653
Graphics Interchange Format (GIF), 509
groups, port number, 478
GUAs (global unicast addresses)
definition of, 408
dynamic addressing for, 417–425, 437
randomly generated interface IDs, 424–425
SLAAC and stateless DHCPv6, 419–420
static configuration of, 413–416
summary of, 437
half-duplex communication, 215, 617, 653
hardware, 47
hardware threats, 545
HDLC (High-Level Data Link Control), 225
Header Checksum field (IPv4 packets), 275
Header Length field (TCP headers), 472
headers
IPv4 (Internet Protocol version 4), 274–276
IPv6 (Internet Protocol version 6), 278–281
TCP (Transmission Control Protocol), 471–472
UDP (User Datagram Protocol), 474
help, Cisco IOS, 58
hexadecimal number systems, 194–197, 240–241
decimal to hexadecimal conversion, 196
definition of, 653
hexadecimal to decimal conversion, 196–197
summary of, 198
hextets, 653
High-Level Data Link Control (HDLC), 225
Hop Limit field (IPv6 packets), 280
hops, 269
host commands, for small business networks, 596–611. See also specific commands
IP configuration on Linux hosts, 599–600
IP configuration on MacOS hosts, 596–601
IP configuration on Windows hosts, 596–598
hostname command, 62, 320, 321
hosts
Cisco IOS. See Cisco IOS
default gateway configuration on, 331–332
definition of, 6
host commands, 596–611. See also specific commands
IP configuration on Linux hosts, 599–600
IP configuration on MacOS hosts, 596–601
IP configuration on Windows hosts, 596–598
default gateways, host routing to, 282–283
host forwarding decisions, 281–282
host/router communications, 223–225
IP addresses. See IP (Internet Protocol) addresses
remote, 282
HTTP (Hypertext Transfer Protocol), 102, 479, 511, 516–518, 580
definition of, 653
HTTPS (HTTP Secure), 102, 479, 511, 515–518, 580
definition of, 653
hub-and-spoke topologies, 211–212
hubs, 653
hubs, Ethernet, 7
Hypertext Transfer Protocol (HTTP), 102, 479, 511, 516–518, 580
IAB (Internet Architecture Board), 16, 109
IANA (Internet Assigned Numbers Authority), 109, 358, 654
ICANN (Internet Corporation for Assigned Names and Numbers), 16, 109
ICMP (Internet Control Message Protocol)
Destination Unreachable, 445–446
Neighbor Advertisement (NA), 446–448
Neighbor Solicitation (NS), 446–448
Router Advertisement (RA), 446–448
Router Solicitation (RS), 446–448
summary of, 454
Time Exceeded, 446
loopback addresses, 450
testing network connectivity with, 455
IDs
device, 422
interfaces, 654
randomly generated interface IDs, 424–425
IEEE (Institute of Electrical and Electronics Engineers), 111, 141, 209
definition of, 654
IEEE 802 LAN/MAN sublayers, 206–207
wireless standards, 165–166, 169–170
IETF (Internet Engineering Task Force), 16, 98, 109, 141, 209
IMAP (Internet Message Access Protocol), 101, 479, 510, 521, 581, 654
INFORMATION REQUEST messages, 529
information theft, 542
initial sequence number (ISN), 487, 654
installation, Packet Tracer, 21–22
Institute of Electrical and Electronics Engineers. See IEEE (Institute of Electrical and Electronics Engineers)
Integrated Services Digital Network (ISDN), 654
interface command, 323
interface configuration mode, 54
interface IDs, 410–411, 424, 654
interface vlan 1 command, 77
interfaces
dual stack addressing, 324–325
summary of, 335
verification commands, 325–330
loopback, 356
randomly generated interface IDs, 424–425
selection of, 573
switch virtual interfaces, 77–78
intermediary devices, 6–7, 654
International Organization for Standardization (ISO), 98, 141, 209, 654
International Telecommunication Union (ITU), 98, 141, 209, 654
International Telecommunications Union-Telecommunication Standardization Sector (ITU-T), 111
internet
internet access technologies for, 17–20
small office and home offices, 17–19
summary of, 38
standards, 109
Internet Architecture Board (IAB), 16, 109
Internet Assigned Numbers Authority (IANA), 109, 358, 654
Internet Control Message Protocol. See ICMP (Internet Control Message Protocol)
Internet Corporation for Assigned Names and Numbers (ICANN), 16, 109
Internet Engineering Task Force (IETF), 16, 98, 109, 141, 209
Internet Message Access Protocol (IMAP), 101, 479, 510, 521, 581, 654
Internet of Things (IoT), 166, 399
internet queries, 655
Internet Research Task Force (IRTF), 109
internet service providers (ISPs), 9, 655
Internet Society (ISOC), 109
Internetwork Operating System. See Cisco IOS
intrusion detection system (IDS), 655
intrusion prevention systems (IPSs), 35, 655
IOS. See Cisco IOS
IoT (Internet of Things), 166, 399
IP (Internet Protocol) addresses, 91, 102, 398–401
ARP (Address Resolution Protocol)
examining with Packet Tracer, 309
maps, 303
replies, 305
requests, 304
role in remote communications, 305–306
summary of, 313
automatic configuration for end devices, 76–77
characteristics of, 271
best-effort delivery, 272
configuration
definition of, 4
destinations on remote network, 299–301
destinations on same network, 298–299
IP addressing services, 521–530
DHCP (Dynamic Host Configuration Protocol), 527–529
DNS (Domain Name System), 522–525
summary of, 535
IPv4. See IPv4 (Internet Protocol version 4) addressing
IPv6. See IPv6 (Internet Protocol version 6) addressing
loopback, pinging, 450
manual configuration for end devices, 75–76
small business networks, 574–576
switch virtual interface configuration, 77–78
troubleshooting
on end devices, 619
on IOS devices, 618
verification of, 77
VoIP (voice over IP), 469, 582
ip address command, 77, 323, 413, 600
ip default-gateway command, 77, 333
ip default-gateway ip-address command, 335–336
ip domain name command, 561
IP telephony, 582
ipconfig /all command, 622
ipconfig command, 77, 78, 423–426, 596–598, 620
ipconfig /displaydns command, 525
IPSs (intrusion prevention systems), 35, 655
IPv4 (Internet Protocol version 4) addressing, 72, 102
broadcast addresses, 349
host addresses, 348
host portion, 342
logical AND, discovering addresses with, 345–346
network addresses, 347–348, 657
network portion, 342
summary of, 390
binary number systems, 176–178
coexistence with IPv6, 399+0095
dual stack addressing, 399–400
tunneling, 400
definition of, 655
destination addresses, 299
directed broadcast, 351–352, 651
DMZ (demilitarized zone), 354–355
broadcast domains and, 359–362
reasons for, 362
summary of, 391
overview of, 342
fragmenting, 274
headers, 274
limitations of, 277
summary of, 292
passing/blocking, 356
routing to Internet, 354
for small business networks, 574–576
source addresses, 299
structured design, 387–389, 392
device address assignment, 389
IPv4 network address planning, 388
with Packet Tracer, 389, 392–393
subnetting, 364–381. See also VLSM (variable-length subnet masking)
DMZ (demilitarized zone), 377
within an octet boundary, 366–367
private versus public address space, 374–377
unused host IPv4 addresses, minimizing, 377–378
types of
link-local, 357
loopback, 356
summary of, 390
VLSM (variable-length subnet masking), 381–387
network address assignments in, 386–387
overview of, 381
subnetting schemes in, 383–385
summary of, 392
IPv6 (Internet Protocol version 6) addressing, 73, 102, 408
preferred format, 402
coexistence with IPv4, 399–401
dual stack addressing, 399–400
tunneling, 400
GUAs (global unicast addresses)
definition of, 408
dynamic addressing for, 417–425, 437
static configuration of, 413–416
summary of, 437
LLAs (link-local addresses)
definition of, 408
dynamic addressing for, 425–430, 437–438
static configuration of, 413–416
summary of, 437
multicast
characteristics of, 93, 406, 430–432, 436–437
solicited-node, 432
summary of, 438
ND (Neighbor Discovery), 309–312, 314
address resolution, 311
examining with Packet Tracer, 312
summary of, 314
with Packet Tracer, 438
router configuration, 435
summary of, 438
unicast, 406, 407–408, 436–437
verifying configuration of, 427–430
ipv6 address command, 323, 413–414
ipv6 address link-local command, 415–416
ipv6 unicast-routing command, 418, 431
IRFT (Internet Research Task Force), 109
ISD (intrusion detection system), 655
ISDN (Integrated Services Digital Network), 654
ISN (initial sequence number), 487, 654
ISO (International Organization for Standardization), 98, 141, 209, 654
ISOC (Internet Society), 109
ISPs (internet service providers), 9, 655
networking jobs for, 36
ITU (International Telecommunication Union), 98, 111, 141, 209, 654
jackets, 655
Japanese Standards Association (JSA/JIS), 141
JPG (Joint Photographic Experts Group), 509
JSA/JIS (Japanese Standards Association), 141
kbps (kilobits per second), 145
kilobits per second (kbps), 145
LACNIC (Regional Latin-American and Caribbean IP Address Registry), 359
LANs (local area network), 12–14. See also network communications; networks; router configuration
definition of, 655
IEEE 802 LAN/MAN sublayers, 206–207
Layer 3 logical addresses, 122–123
layered security, 553
layers, OSI model. See OSI (Open System Interconnection) model
layers, TCP/IP model. See TCP/IP (Transmission Control Protocol/Internet Protocol) model
LC (Lucent Connector) connectors, 162
LDAP (Lightweight Directory Access Protocol), 655
leading zeros
legacy classful addressing, 357–358, 648
legacy LAN topologies, 214
Length field (UDP headers), 474
Lightweight Directory Access Protocol (LDAP), 655
limited broadcast, 655
line console 0 command, 63
line of sight wireless, 655
line vty 0 15 command, 64
Link Layer Discovery Protocol (LLDP), 247
link-local addresses. See LLAs (link-local addresses)
Linux hosts, IP (Internet Protocol) configuration on, 599–600
LLAs (link-local addresses), 357
dynamic addressing for, 425–430, 437–438
dynamic LLA creation, 425
dynamic LLA on Cisco routers, 426–427
dynamic LLA on Windows, 425–426
IPv6 address configuration, verification of, 427–430
with Packet Tracer, 430
static configuration of, 413–416
summary of, 437
LLC (Logical Link Control), 206, 235, 656
LLDP (Link Layer Discovery Protocol), 247
local area networks. See LANs (local area network)
AND, logical, 645
logical addresses. See IP (Internet Protocol) addresses
Logical Link Control (LLC), 206, 235, 656
logical NOT, 345
logical OR, 345
logical topologies, 10–11, 209–211
logical topology diagrams, 656
login block-for command, 560
login local command, 562
long-haul networks, 160
loopback adapters, 656
loopback addresses, 356, 450, 656
loopback interfaces, 656
loopback interfaces, pinging, 356
LTE, 656
Lucent Connector (LC) connectors, 162
MAC (media access control) addresses, 124, 206–207, 239–248
on connected switches, 252
definition of, 656
summary of, 261
switch learning and forwarding, 250–251
viewing, 254
ARP (Address Resolution Protocol)
examining with Packet Tracer, 309
replies, 305
requests, 304
role in remote communications, 305–306
summary of, 313
definition of, 656
destinations on remote network, 299–301
destinations on same network, 298–299
hexadecimal number system, 240–241
MAC (media access control) sublayer, 236–237. See also MAC (media access control) addresses
data encapsulation, 236
media access, 237
MacOS hosts, IP configuration on, 596–601
maintenance threats, 545
viruses, 546
man-in-the-middle attack, 549
MANs (metropolitan-area networks), 656
maps (ARP), 303
Matroska Video (MKV), 509
maximum segment size (MSS), 491–492
maximum transmission unit (MTU), 492, 656
Mbps (megabits per second), 145
mdix auto command, 259
media access
data link layer functions, 207–208
MAC (media access control) sublayer, 237
media access control. See MAC (media access control) addresses
media independence, 273–274, 656
megabits per second (Mbps), 145
mesh topologies, 212
messages. See also data encapsulation
decoding, 89
destinations, 87
DHCP (Dynamic Host Configuration Protocol), 528–529
DNS (Domain Name System), 524–525
ICMP (Internet Control Message Protocol), 444–448
Destination Unreachable, 445–446
Neighbor Advertisement (NA), 446–448
Neighbor Solicitation (NS), 446–448
Router Advertisement (RA), 446–448
Router Solicitation (RS), 446–448
summary of, 454
Time Exceeded, 446
ND (Neighbor Discovery), 309–310
sources, 87
metropolitan-area networks (MANs), 656
mismatch issues, troubleshooting, 617
mitigation techniques, 552–558
AAA (authentication, authorization, and accounting), 555
defense-in-depth approach, 553
endpoint security, 558
summary of, 565
updates and patches, 554
MKV (Matroska Video), 509
MMF (multimode fiber), 160, 657
models. See OSI (Open System Interconnection) model; TCP/IP (Transmission Control Protocol/Internet Protocol) model
modems, 656
Motion Picture Experts Group (MPG), 509
MOV (QuickTime Video), 509
MPG (Motion Picture Experts Group), 509
MSS (maximum segment size), 491–492
MTU (maximum transmission unit), 492, 656
multiaccess networks, 216
multicast IPv4 addresses, 352–353, 390
multicast IPv6 addresses
assigned multicast, 646
characteristics of, 93, 406, 430–432, 436–437
solicited-node, 432
summary of, 438
multicast MAC (media access control) addresses, 247–248
multicast transmission, 656–657
multimeters, 657
multimode fiber (MMF), 160, 657
multiplexing, 117–118, 132, 657
MX records, 524
NA (Neighbor Advertisement) message, 309, 446–448, 657
names, Cisco IOS device, 61–62
NAS (network attached storage), 657
NAT (Network Address Translation), 354, 398, 657
NAT64 (Network Address Translation 64), 400–401
Packet Tracer, 60
summary of, 79
Tera Term, 60
ND (Neighbor Discovery), 245, 309–312, 446
address resolution, 311
definition of, 657
examining with Packet Tracer, 312
summary of, 314
Neighbor Advertisement (NA) messages, 309, 446–448, 657
Neighbor Discovery. See ND (Neighbor Discovery)
Neighbor Solicitation (NS) messages, 309, 446–448, 657
netsh interface ip delete arpcache command, 602
netstat -r command, 283–284, 293
NetWare, 99
network access layer, 103, 114
Network Address Translation 64 (NAT64), 400–401
Network Address Translation (NAT), 354, 398, 657
network addresses, 347–348, 657
network applications, 578
network architecture, definition of, 657
network attached storage (NAS), 657
network communications. See also OSI (Open System Interconnection) model; TCP/IP (Transmission Control Protocol/Internet Protocol) model
communications standards, 111
data link addresses, 124, 126–129
devices on same network, 123
Layer 3 logical addresses, 122–123
network layer addresses, 125
overview of, 121
summary of, 132
de-encapsulation, 120–121, 132
example of, 120
PDUs (protocol data units), 118–120, 132
summary of, 132
definition of, 648
messages
decoding, 89
destination, 87
sources, 87
protocol suites, 97–107. See also TCP/IP (Transmission Control Protocol/Internet Protocol) model
summary of, 130
protocols. See also specific protocols
interaction between, 96
summary of, 130
rule establishment for, 88, 130
standards organizations, 108–111
communications standards, 111
electronic standards, 111
internet standards, 109
summary of, 131
network infrastructure, definition of, 657
network interface cards (NICs), 9, 139, 168, 657
network layer. See also IP (Internet Protocol) addresses
characteristics of, 268–274, 292
hops, 269
host forwarding decisions, 281–282
IP router routing tables, 286–287
router packet forwarding decisions, 285–286
networking jobs, 36
networks. See also addresses; internet; network communications; router configuration; small business network management
architecture of, 23
BYOD (bring your own device), 28
clients, 4
connectivity, testing
with Packet Tracer, 455
with ping tests, 455
with traceroute, 455
data flow through, 6
end devices, 6
LAN (local area network) design, 12–14. See also router configuration
IEEE 802 LAN/MAN sublayers, 206–207
prefixes, 345
fault tolerance, 24
QoS (quality of service), 25–26
summary of, 38
remote, 661
role of IT professionals in, 35–36, 40
summary of, 39
broadcast domains and, 359–362
definition of, 662
reasons for, 362
summary of, 391
servers
definition of, 4
smart homes, 31
SOHO (small office and home office) networks, 12
definition of, 10
physical, 10
types of, 37
video communications tools for, 29
WANs (wide area networks), 14–15
wireless, 32
networksetup -getinfo command, 601
networksetup -listallnetworkservices command, 601
Next Header field (IPv6 packets), 280
next hop, 657
nibble boundary, 657
NICs (network interface cards), 9, 139, 168, 657
no hostname command, 62
no ip directed-broadcasts command, 352
no ip http server command, 563
no shutdown command, 77, 323–324, 335
node icon, 94
noise, 658
nonreturn to zero (NRZ), 658
Non-Volatile Memory Express (NVMe), 658
nonvolatile random-access memory (NVRAM), 67, 658
notation, positional. See positional notation
Novell NetWare, 99
NRZ (nonreturn to zero), 658
NS (Neighbor Solicitation) message, 309, 446–448, 657
NS records, 524
nslookup command, 526–527, 530, 547, 622–623, 658
number systems
binary positional notation, 178–180
binary to decimal conversion, 180–181
decimal to binary conversion, 182–193
summary of, 198
decimal to hexadecimal conversion, 196
hexadecimal to decimal conversion, 196–197
summary of, 198
653, 653
overview of, 176
numbers, port
definition of, 465
destination, 650
groups of, 478
multiple separation communications with, 476
well-known, 479
NVMe (Non-Volatile Memory Express), 658
octet boundary, 658
octets, 658
Open Samples command (Packet Tracer), 22
Open Shortest Path First (OSPF), 103
Open System Interconnection model. See OSI (Open System Interconnection) model
OpenDNS, 622
operating systems (OSs), 46–47, 48–49
optical fiber cabling. See fiber-optic cabling
OR, logical, 345
.org domain, 525
organizationally unique identifiers (OUIs), 242, 422, 658
OSI (Open System Interconnection) model, 508. See also TCP/IP (Transmission Control Protocol/Internet Protocol) model
application layer
definition of, 508
file sharing services, 530–533
IP addressing services, 521–530
peer-to-peer applications, 513–515
peer-to-peer networks, 512–513
purpose of, 508
summary of, 534
benefits of using, 112
data link layer
IEEE 802 LAN/MAN sublayers, 206–207
standards, 209
definition of, 98
network layer. See also IP (Internet Protocol) addresses
characteristics of, 268–274, 292
hops, 269
Packet Tracer simulation, 116
physical layer. See also copper cabling; fiber-optic cabling
characteristics of, 141–146, 168
summary of, 168
wireless media, 164–167, 169–170
summary of, 131
TCP/IP model compared to, 115–116
OSPF (Open Shortest Path First), 103
OSs (operating systems), 46–47, 48–49
OUIs (organizationally unique identifiers), 242, 422, 658
out-of-band management, 49
overhead, 658
P2P (peer-to-peer) applications, 513–515
P2P (peer-to-peer) networks, 5, 512–513, 534, 658
P2PRG (Peer-to-Peer Research Group), 109
packet filtering, 557
packet forwarding. See forwarding
packet switched. See switches
Packet Tracer
ARP table examination with, 309
Cisco IOS navigation with, 60
connecting routers with, 334
device configuration with, 71, 336
IPv6 addressing configuration with, 430
IPv6 ND examination with, 312
IPv6 subnetting with, 438
physical layer connections with, 167
reference model simulations, 116
router configuration with, 323
testing network connectivity with, 455
VLSM design and implementation, 389, 392–393
packets
headers, 274
limitations of, 277
summary of, 292
router forwarding decisions, 285–286
PANs (personal-area networks), 658
parallel ports, 658
passing IPv4 addresses, 356
passphrases, 560
password attacks, 548
passwords
Cisco IOS devices
enable, 651
patches, 554
Payload Length field (IPv6 packets), 280
PDUs (protocol data units), 118–120, 132, 660
peers, 512
peer-to-peer applications, 513–515
peer-to-peer networks, 5, 512–513, 534, 658
Peer-to-Peer Research Group (P2PRG), 109
personal-area network (PAN), 658
physical addresses. See MAC (media access control) addresses
physical layer
components, 142
standards organizations, 141
summary of, 168
fiber-optic cabling versus, 163–164
rollover cables, 157
STP (shielded twisted pair), 150–151
UTP (unshielded twisted pair), 148–150, 152–158, 169
definition of, 114
copper cabling versus, 163–164
fiber-optic connectors, 161–162
industry applications of, 160
multimode fiber, 160
single-mode fiber, 159
summary of, 169
summary of, 168
wireless LANs (WLANs), 166–167
physical ports. See ports
physical topologies, 10, 209–211, 659
physical topology diagrams, 659
ping command
default gateway testing with, 450–451
definition of, 659
device connectivity verification with, 78
IOS command syntax, 57
IPv6 verification with, 429
lab exercises for, 455
loopback interface testing with, 356, 450
network baseline assessment with, 593–596
remote host testing with, 451–452
small business network verification with, 586–590
PNG (Portable Network Graphics), 509
PoE (Power over Ethernet), 659
Point-to-Point Protocol (PPP), 225
point-to-point topologies, 211, 213
policy vulnerabilities, 544
pools, DHCP (Dynamic Host Configuration Protocol), 527
POP (Post Office Protocol), 479, 520, 659
POP3 (Post Office Protocol), 101, 510, 659
Portable Network Graphics (PNG), 509
ports, 9
definition of, 659
port numbers
destination, 650
groups of, 478
multiple separation communications with, 476
well-known, 479
redirection, 549
registry, 479
selection of, 573
positional notation
definition of, 178
POST (power-on self-test), 659
Post Office Protocol (POP3), 101, 479, 510, 520, 659
POST requests, 517
Power over Ethernet (PoE), 659
powerline networking, 31–32, 659
power-on self-test (POST), 659
PPP (Point-to-Point Protocol), 225
Preamble field (Ethernet frames), 238
preferred format, IPv6, 402–406, 659
presentation layer, 534
definition of, 113
private IPv4 addresses, 353–354, 374–377, 659
privileged EXEC mode, 53, 64, 659
protocol analyzers, 660
protocol data units (PDUs), 118–120, 132, 660
Protocol field (IPv4 packets), 276
protocol suites, 97–107. See also TCP/IP (Transmission Control Protocol/Internet Protocol) model
definition of, 660
protocols. See also specific protocols
interaction between, 96
proxy servers, 660
PSH flag, 486
public IPv4 addresses, 353–354, 374–377, 660
PUT requests, 517
qBittorrent, 514
QoS (quality of service), 25–26, 582, 660
quality-of-service (QoS), 660
queries, internet, 655
queuing, 660
QuickTime Video (MOV), 509
RA (Router Advertisement) messages, 310, 417–418, 446–448, 661
radio frequency interference (RFI), 147, 660
RADIUS (Remote Authentication Dial-in User Service), 495
RAM (random-access memory), 67, 660
random-access memory (RAM), 660
randomly generated interface IDs, 424–425
read-only memory (ROM), 243, 660
real-time traffic, 660
Real-Time Transport Control Protocol (RTCP), 582
Real-Time Transport Protocol (RTP), 582
reconnaissance attacks, 547–548, 660
Redirect message, 310
reference models. See OSI (Open System Interconnection) model; TCP/IP (Transmission Control Protocol/Internet Protocol) model
Regional Internet Registries (RIRs), 358–359
regional Internet registry (RIR), 661
Regional Latin-American and Caribbean IP Address Registry (LACNIC), 359
reliability, 38
IP (Internet Protocol), 273–274
of protocols, 96
TCP (Transmission Control Protocol), 486–490, 500–501
UDP (User Datagram Protocol), 494
reload command, 68
Remote Authentication Dial-in User Service (RADIUS), 495
remote communications, ARP (Address Resolution Protocol) in, 305–306
remote hosts
definition of, 282
remote networks, 661
repeaters, 661
replies (ARP), 305
REPLY messages, 529
Representational State Transfer (REST), 102
representations, network, 8–10, 37
requests
ARP (Address Resolution Protocol), 304
TCP (Transmission Control Protocol), 481–482
UDP (User Datagram Protocol), 495–497
requests for comments (RFCs), 209, 661
Réseaux IP Européens Network Coordination Centre (RIPE NCC), 359
Reserved field (TCP headers), 472
resolution, 613
response timeout, 661
responses
TCP (Transmission Control Protocol), 482–483
timeout, 92
UDP (User Datagram Protocol), 497–498
REST (Representational State Transfer), 102
RFCs (requests for comments), 209, 661
RFI (radio frequency interference), 147, 660
RIPE NCC (Réseaux IP Européens Network Coordination Centre), 359
RIR (regional Internet registry), 661
RIRs (Regional Internet Registries), 358–359
RJ-11 connectors, 661
rollover cables, 157
ROM (read-only memory), 243, 660
round-trip time (RTT), 661
Router Advertisement (RA) messages, 310, 417–418, 446–448, 661
ARP tables, displaying, 306–307
basic configuration example, 321–323
banner warnings, 322
device name, 321
initial router settings, 323
running configuration, saving, 322
secure access, 322
basic configuration steps, 320–321, 335
troubleshooting, 334
dynamic LLAs (link-local addresses) on, 426–427
host/router communications, 223–225
dual stack addressing, 324–325
summary of, 335
verification commands, 325–330
Router Solicitation (RS) messages, 310, 417–418, 446–448, 661
routers, 661
routing, 285–291. See also router configuration
definition of, 661
host forwarding decisions, 281–282
router packet forwarding decisions, 285–286
routing tables, 286–287, 290–291
RS (Router Solicitation) messages, 310, 417–418, 446–448, 661
RST flag, 486
RTCP (Real-Time Transport Control Protocol), 582
RTP (Real-Time Transport Protocol), 582
RTT (round-trip time), 661
running configuration, altering, 68
running-config file, 67
SACK (selective Acknowledgement), 489
SACK (selective acknowledgment), 662
satellite internet access, 19, 661
SC (subscriber connector) connectors, 161
scalability, small network, 24–25, 583–586, 624
employee network utilization, 584–586
small network growth, 583
SDSL (symmetric DSL), 20
Secure FTP (SFTP), 101, 581, 663
Secure Shell (SSH), 50, 479, 561–562, 580, 662
SecureCRT, 50
AAA (authentication, authorization, and accounting), 555
defense-in-depth approach, 553
endpoint security, 558
updates and patches, 554
attack mitigation, 565
summary of, 565
summary of, 566
unused services, disabling, 563–564
summary of, 39
summary of, 565
security passwords min-length command, 560
segmentation, network, 359–362
broadcast domains and, 359–362
definition of, 662
reasons for, 362
summary of, 391
ACK (Acknowledgement), 472, 484–485, 486, 488
definition of, 662
MSS (maximum segment size), 491–492
selective Acknowledgement (SACK), 489
selective acknowledgment (SACK), 662
SEQ (sequence) number, 488
Sequence Number field (TCP headers), 472
sequence numbers, 662
Server Message Block (SMB), 531–533, 662, 663
servers
definition of, 4
TCP (Transmission Control Protocol)
connection establishment, 483–484
UDP (User Datagram Protocol), 495
service password-encryption command, 64, 560
services
application layer, 579
FTP (File Transfer Protocol), 530
SMB (Server Message Block), 531–533
DHCP (Dynamic Host Configuration Protocol), 527–529
DNS (Domain Name System), 522–525
summary of, 535
session layer, 534
definition of, 113
sessions, 662
SFP (small form-factor pluggable) devices, 161
SFTP (Secure FTP), 101, 581, 663
sharing services. See file sharing services
shell, 47
shells, 662
shielded twisted pair (STP) cable, 150–151, 662
show cdp neighbors command, 609–610
show control-plane host open-ports command, 563
show interfaces command, 328, 335, 603, 604–605
show ip interface brief command, 325–326, 335, 610–611, 618
show ip interface command, 329, 335, 603, 605–606, 618
show ip ports all command, 563
show ip route command, 290–291, 293, 327, 335, 603, 606–607, 620
show ipv6 interface brief command, 325–327, 335, 427–428
show ipv6 interface command, 330, 335
show ipv6 route command, 327–328, 335, 428–429
show protocols command, 603, 607
show running-config command, 65, 67–68, 70, 333, 603–604
show startup-config command, 70
show version command, 603, 608, 611
signal attenuation, 147
Simple Mail Transfer Protocol (SMTP), 101, 479, 510, 519–520, 581, 662, 663
simplex LC (Lucent Connector) connectors, 162
single-mode fiber (SMF), 159, 662
size
SLAAC (stateless address autoconfiguration), 101
randomly generated interface IDs, 424–425
slash notation, 662
sliding window protocol, 491
small business network management
applications
summary of, 624
voice/video applications, 582
device selection, 573–574, 624
expandability, 573
host and IOS commands for, 596–611
IP configuration on Linux hosts, 599–600
IP configuration on MacOS hosts, 596–601
IP configuration on Windows hosts, 596–598
show ip interface, 603, 605–606
show ip interface brief, 610–611
internet access technologies for, 19–20
summary of, 624
scalability, 624
employee network utilization, 584–586
small network growth, 583
troubleshooting methodologies, 611–616
resolution versus escalation in, 613
summary of, 626
terminal monitor command, 615–616
troubleshooting scenarios, 616–623
default gateway issues, 619–620
duplex operation, 617
IP addressing on end devices, 619
IP addressing on IOS devices, 618
mismatch issues, 617
verifying connectivity of, 586–596
summary of, 625
small office and home office (SOHO) networks, 12, 17–19, 662
SMB (Server Message Block), 531–533, 662, 663
SMF (single-mode fiber), 159, 662
SMTP (Simple Mail Transfer Protocol), 479, 510, 519–520, 581, 662
SNMP (Simple Network Management Protocol), 663
sockets, 663
SOHO (small office and home office) networks, 12, 17–19, 662
SOLICIT messages, 529
Solicitation messages. See RS (Router Solicitation) messages
solicited-node IPv6 multicast addresses, 432, 663
Source IPv4 Address field, 276
source IPv4 addresses, 122, 123, 125, 299, 663
Source IPv6 Address field, 280
Source MAC Address field, 238
source MAC addresses, 124, 126, 243, 299, 301, 305
Source Port field
TCP headers, 472
UDP headers, 474
sources, 87
Spanning Tree Protocol (STP), 247
SPI (stateful packet inspection), 557, 663
spoofing, 663
spyware, 33
SSH (Secure Shell), 50, 479, 561–562, 580, 662
ST (straight-tip) connectors, 161
communications, 111
data link layer, 209
electronic, 111
internet, 109
physical layer, 141
UTP (unshielded twisted pair) cable, 153–156
Start Frame Delimiter field (Ethernet frames), 238
startup-config file, 67
stateful packet inspection (SPI), 557, 663
stateful protocols, 471. See also TCP (Transmission Control Protocol)
stateless address autoconfiguration. See SLAAC (stateless address autoconfiguration)
stateless DHCPv6, 418–420, 663
stateless protocols, 468
static addressing, 527
static configuration
GUAs (global unicast addresses), 413–416
LLAs (link-local addresses), 413–416
static route propagation, 663
store-and-forward switching, 254–255, 664
STP (shielded twisted pair), 150–151, 662
STP (Spanning Tree Protocol), 247
straight-through UTP cables, 157
straight-tip (ST) connectors, 161
strong passwords, 560
structured design, IPv4, 387–389, 392
device address assignment, 389
IPv4 network address planning, 388
with Packet Tracer, 389, 392–393
sublayers, IEEE 802 LAN/MAN, 206–207
submarine cable networks, 160
definition of, 664
IPv4
DMZ (demilitarized zone), 377
within an octet boundary, 366–367
private versus public address space, 374–377
unused host IPv4 addresses, minimizing, 377–378
VLSM (variable-length subnet masking), 381–387
with Packet Tracer, 438
router configuration, 435
summary of, 438
VLSM (variable-length subnet masking), 381–387
network address assignments in, 386–387
overview of, 381
subnetting schemes in, 383–385
summary of, 392
subscriber connector (SC) connectors, 161
SVI (switch virtual interface), 664
SVIs (switch virtual interfaces), 74
swarms, 514
switch fabric, 664
switch virtual interfaces (SVIs), 74
switched virtual interface (SVI), 664
switches
asymmetric switching, 646
Cisco IOS. See Cisco IOS
default gateway configuration on, 332–334
definition of, 664
Ethernet
cut-through switching, 255–256, 649
fast-forward switching, 256, 652
fragment-free switching, 256, 652–653
memory buffering on, 257
store-and-forward switching, 254–255, 664
frame forwarding methods on, 254–255, 262
learning and forwarding, 248–249
MAC addressing for. See MAC (media access control) addresses
switch virtual interfaces, 77–78
symmetric DSL (SDSL), 20
SYN flag, 486
Syntax Checker
Cisco IOS device configuration with, 66
Cisco IOS navigation with, 55–56
default gateway configuration with, 334
nslookup command, 527
router configuration with, 323
syslog, 664
system speakers, 664
tables
ARP (Address Resolution Protocol)
removing entries from, 306–307
binary positional value, 182–186
CAM (content addressable memory), 649
MAC (media access control) address, 248–254
on connected switches, 252
definition of, 656
switch learning and forwarding, 248–249
viewing, 254
routing, 283–284, 286–287, 290–291
TCP (Transmission Control Protocol), 102
congestion avoidance, 493
connection establishment, 483–484
data loss and retransmission, 486–487
definition of, 665
MSS (maximum segment size), 491–492
reliability of, 467–468, 486–490, 500–501
summary of, 499
UDP (User Datagram Protocol) compared to, 469–470
TCP/IP (Transmission Control Protocol/Internet Protocol) model
application layer
definition of, 508
file sharing services, 530–533
IP addressing services, 521–530
peer-to-peer applications, 513–515
peer-to-peer networks, 512–513
purpose of, 508
summary of, 534
benefits of using, 112
communication process in, 103–107
network access layer, 103
network layer. See also IP (Internet Protocol) addresses
characteristics of, 268–274, 292
hops, 269
OSI model compared to, 115–116
overview of, 114
Packet Tracer simulation, 116
physical layer. See also copper cabling; fiber-optic cabling
characteristics of, 141–146, 168
summary of, 168
wireless media, 164–167, 169–170
summary of, 131
transport layer, 102
technological vulnerabilities, 543
Telecommunications Industry Association (TIA), 111, 664
Telecommunications Industry Association/Electronic Industries Association (TIA/EIA), 141
terabits per second, 145
terminal emulation programs, 50–52, 664
terminal monitor command, 615–616
test-net addresses, 665
text files, capturing configuration to, 68–71
TFTP (Trivial File Transfer Protocol), 101, 479, 511, 665
three-way handshake, 665
three-way handshake (TCP), 485–486
TIA (Telecommunications Industry Association), 111, 141, 664
Time Exceeded messages, 446
timeout, response, 92
Time-to-Live (TTL) field, 275, 446, 453, 665
Token Ring LAN technologies, 214, 217
top-level domains, 525
topologies
access control methods, 216–217
contention-based access, 216–220
controlled access, 217
data link frame, 229
full-duplex communication, 215–216, 653
half-duplex communication, 215, 653
LAN (local area network), 213–214
summary of, 228
WAN (wide area network), 211–213
definition of, 665
small business networks, 572–573. See also small business network management
definition of, 10
physical, 10
ToS (Type of Service) field, 275
traceroute command
definition of, 665
IOS command syntax, 57
small business network verification with, 590–594
testing network connectivity with, 452–453, 455
Traffic Class field (IPv6 packets), 280
traffice prioritization, 665
Transmission Control Protocol. See TCP (Transmission Control Protocol)
transport input command, 320, 562
transport input ssh command, 563
transport layer
overview of, 102
port numbers
definition of, 465
groups of, 478
multiple separation communications with, 476
well-known, 479
protocols, 467
role of, 462
TCP (Transmission Control Protocol)
congestion avoidance, 493
connection establishment, 483–484
data loss and retransmission, 489
MSS (maximum segment size), 491–492
reliability of, 467–468, 486–490, 500–501
summary of, 499
UDP (User Datagram Protocol) compared to, 469–471
UDP (User Datagram Protocol)
datagram reassembly, 494
headers, 474
overview of, 473
server processes, 495
TCP (Transmission Control Protocol) compared to, 469–470
Trivial File Transfer Protocol (TFTP), 101, 479, 511, 665
troubleshooting
default gateways, 334
definition of, 665
small business networks, 611–623
default gateway issues, 619–620
duplex operation, 617
IP addressing on end devices, 619
IP addressing on IOS devices, 618
mismatch issues, 617
resolution versus escalation in, 613
terminal monitor command, 615–616
TTL (Time-to-Live) field, 275, 446, 453, 665
twisted-pair. See STP (shielded twisted pair); UTP (unshielded twisted pair)
Type of Service (ToS) field (IPv4 packets), 275
Type/Length field (Ethernet frames), 239
UDP (User Datagram Protocol)
datagram reassembly, 494
headers, 474
overview of, 473
server processes, 495
TCP (Transmission Control Protocol) compared to, 469–470
undebug command, 614
unicast, 93
unknown, 250
unicast transmission
definition of, 665
unknown, 666
uniform resource locators (URLs), 515, 557
unique local addresses, 408, 665–666
unshielded twisted pair. See UTP (unshielded twisted pair) cable
unspecified addresses, 666
unused host IPv4 addresses, minimizing, 377–378
unused services, disabling, 563–564
updates, security, 554
uploads, 512
URG flag, 486
Urgent field (TCP headers), 472
URLs (uniform resource locators), 515, 557
User Datagram Protocol. See UDP (User Datagram Protocol)
user passwords. See passwords
username command, 562
uTorrent, 514
UTP (unshielded twisted pair), 152–158
crossover, 157
straight-through, 157
summary of, 169
variable-length subnet masking. See VLSM (variable-length subnet masking)
verification. See also configuration
of device connectivity, 78, 80
of IP (Internet Protocol) configuration, 77
show interfaces command, 328
show ip interface brief command, 326
show ip interface command, 329
show ip route command, 327
show ipv6 interface brief command, 326–327
show ipv6 interface command, 330
show ipv6 route command, 327–328
of small business network connectivity, 586–596
summary of, 624
Version field
IPv4 packets, 275
IPv6 packets, 280
video, file formats for, 509
virtual circuits, 666
virtual classrooms, 666
virtual private networks (VPNs), 35
virtual terminal (vty), 64
virtualization, 666
VLANs (virtual local area networks), 666
VLSM (variable-length subnet masking), 381–387
address conservation, 381–383, 385
definition of, 666
network address assignments in, 386–387
overview of, 381
summary of, 392
voice applications, 582
VoIP (voice over IP), 469, 582, 666–667
volatile memory, 667
VPNs (virtual private networks), 35
WANs (wide area networks), 14–15
mesh, 212
WAPs (wireless access points), 138, 166, 667
weak passwords, 559
HTTP (Hypertext Transfer Protocol), 516–518
summary of, 534
well-known IPv6 multicast addresses, 430–431, 667
well-known port number, 479
whois command, 547
wide area networks. See WANs (wide area networks)
Wi-Fi Alliance, 165–166, 169–170
Wi-Fi analyzer, 667
window size, 472, 490–491, 667
Window Size field (TCP headers), 472
Windows computers
ARP tables, displaying, 307
Data Usage tool, 585
dynamic LLAs (link-local addresses) on, 425–426
IP (Internet Protocol) configuration on, 596–598
wireless access points, 138, 166, 667
wireless internet service providers (WISPs), 32, 668
wireless LANs (WLANs), 103, 166–167, 234, 668
wireless LANs (WLANs), 166–167
wireless mesh network, 668
wireless network interface card (NIC), 668
wireless networks, 32
wireless routers, 668
WISPs (wireless internet service providers), 32, 668
WLANs (wireless LANs), 103, 166–167, 234, 668
WMN (wireless mesh network), 668
Worldwide Interoperability for Microware Access (WiMAX), 667
Worldwide Interoperability for Microwave Access (WiMAX), 166
X.25, 225
zero-day attacks, 33