Index
Symbols
3COM, Ethernet development, 107
10-Gigabit Ethernet SFP modules, 534
802.11 Wireless frames, 438-440
A
A records, 155
AAA network security services, 568-569
abbreviated commands/keywords and IOS, 73-74
access attacks (security), 565
access networks, FTTH, 465
access technologies (Internet), 32
business access
dedicated leased line, 34
DSL, 35
Metro Ethernet, 35
satellite, 35
remote access
cable, 33
cellular, 33
dial-up (telephone), 34
DSL, 33
satellite, 33
accessing
CLI
AUX ports, 61
console port, 60
console ports, 59
SSH protocol, 60
Telnet, 60
terminal emulation programs, 61
IOS
AUX ports, 61
SSH protocol, 60
Telnet, 60
local resources (data delivery)
communicating with devices on the same network, 128-129
data link addresses, 128
out-of-band access, defining, 59
privileged EXEC access, securing, 80
remote resources (data delivery)
communicating with devices on remote networks, 131-132
data link addresses, 132
default gateways, 130
network addresses, 131
user EXEC access, securing, 81-82
accounting, network security, 569
ACK (acknowledgement) control flags, TCP three-way handshakes, 192-193
ACK (acknowledgement) numbers, confirming receipt of TCP segments, 196-197
acknowledgements
expectational acknowledgement, 196
SACK, 198
ACL (Access Control Lists), 44
address pools and DHCP, 293
addressing. See IPv4 addressing, IPv6 addressing
administration (Internet), 31
administrative distance, remote network routes, 235
ADSL (Asymmetric Digital Subscriber Line) Internet connections, 35
adware, 43
AM (Amplitude Modulation), 448
ANDing (AND operation), IPv4 addressing, 287-290
ANSI (American National Standards Institute), data link layer standards, 418
antispyware, 44
antivirus software, 44
anycast IPv6 addresses, 318
AP (Access Points), 475
appliance-based firewalls, 570
application filtering (firewalls), network security, 570
application layer
client/server model and application protocols, 148
defining, 141
network-aware applications, 144
OSI reference model, 140
P2P networks and application protocols, 145-147
services
defining, 144
small networks, 554
TCP/IP protocol suite, 141
BOOTP, 143
FTP, 143
IMAP, 143
Telnet, 143
TFTP, 143
application layer protocol, 105
application interfaces and OSI reference model, 145
architectures (network)
Cisco Borderless Network Architectures, 46
Cisco Unified Data Center, 47
collaboration architectures, 46-47
arguments, defining, 67
ARP (Address Resolution Protocol)
ARP caches and RAM, 242
ARP poisoning, 515
ARP spoofing, 515
IP addresses, resolving, 504
MAC addresses, 130
problems with
mitigating, 515
overhead, 514
security, 515
remote communication and, 508-510
tables
arp -a command, 513
maintaining, 505
networking devices, 512
removing entries from, 512
show ip arp command, 512
ARPANET (Advanced Research Projects Agency Network)
Internet development, 107
RFC development, 119
Arrows and IOS, 73
ASCII (American Standard Code for Information Interchange)
binary notation, IPv4 addressing, 267
Digital Translator, 268
assigned multicast IPv6 addresses, 337
assigning interfaces, testing assignments, 94
asynchronous data signals, 448
attacks (security), 564
access attacks, 565
defining, 562
reconnaissance attacks, 565
attenuation (signal), 452
audio files and podcasting, 8
authentication
IPv6 packets, 222
authorization, network security, 569
Auto-MDIX, LAN switches, 522
AUX (auxiliary) ports
CLI environments, accessing via routers, 245
IOS access, 61
routers and, 244
availability (data), network security, 23
B
backbone cabling, 463
backups
IOS configuration files
backing up via text capture (Tera Term), 87, 600
backing up via text files, 600
backing up via USB flash drives, 603
restoring via USB flash drives, 605
network security, 567
bandwidth, physical layer (OSI reference model), 449-450
banners
device security, 575
base (positional notation), 268
baselines (networks), determining, 581-582
BCP (Best Current Practices), 121
best effort (unreliable) delivery, IP, 215-216
BIA (burned-in addresses). See MAC addresses
binary notation
converting
binary notation to decimal addressing, 271
decimal addressing to binary notation, 272, 275-277, 290
binary notation conversion to decimal addressing, 271
decimal address conversion to binary notation, 272, 275-277, 290
positional notation, 268
BIND (Berkeley Internet Name Domain) and DNS, 155-156
bitwise AND operation, IPv4 addressing, 287-290
blocks, SAN, 29. See also disk arrays
blogs (weblogs), 10
BOOTP (Bootstrap Protocol), application layer, 143
bootset files, router bootups, 247
Borderless Network Architectures, 46
branches and routers, 241
broadcast addresses
directed broadcast addressing, 295
limited broadcast addressing, 295
MAC addresses, 501
broadcast domains, 295
businesses
business Internet connections
dedicated leased line, 34
DSL, 35
Metro Ethernet, 35
satellite, 35
employees and security breaches, 43
Internet’s changes to, 9
bus topologies, 426
BYOD (Bring Your Own Device), 38
accessibility, 37
collaboration tools, 37
defining, 36
QoS, 37
security, 37
bytes, hexadecimal numbering, 311
C
cable
backbone cabling, 463
central equipment rooms, 463
copper cable, 452
electrical hazards, 457
fiber optic cable versus, 471-472
fire hazards, 457
physical layer (OSI reference model), 442, 445
safety, 457
entrance facilities, 463
fiber optic cable, 442
components of, 466
end finish errors, 470
end gap errors, 470
misalignment errors, 470
network fiber-optic connectors, 468-469
properties of, 465
SMF, 467
testing, 470
horizontal cabling, 462
telecommunications rooms, 463
Ethernet crossover cable, 461
Ethernet straight through cable, 461
rollover cable, 462
testing, 464
types of, 461
work areas, 462
cable Internet connections, 33, 457
capturing text, configuration backups, 87
Catalyst 2960 switches, fixed LAN switch configurations, 529-530
Catalyst 3560 switches, fixed LAN switch configurations, 530
Catalyst 3750 switches, fixed LAN switch configurations, 530
Catalyst 4500 switches, modular LAN switch configurations, 531-532
Catalyst 4900 switches, modular LAN switch configurations, 532
Catalyst 6500 switches, modular LAN switch configurations, 532
Catalyst Express 500 switches, fixed LAN switch configurations, 528
CCNA (Cisco Certified Network Associate) certification, 47-48
cellular Internet connections, 33
central equipment rooms, LAN cabling, 463
Cerf, Vinton, TCP protocol suite development, 107
CIDR (Classless Inter-Domain Routing), 303
circuit-switched networks, 15-16
Cisco Borderless Network Architectures, 46
Cisco Catalyst switches, 61
Cisco Express Forwarding, Layer 3 LAN switches, 536-537
Cisco routers and USB ports, 602-603
Cisco Unified Data Center, 47
classful addressing
class A address space, 301
class B address space, 301
class C address space, 302
limits of, 303
classless addressing (CIDR), 303
CLI (Command-Line Interface)
accessing
AUX ports, 61
SSH protocol, 60
Telnet, 60
terminal emulation programs, 61
CLI prompt, user EXEC mode, 63
modes of operation, 62
command prompts, 64
global configuration mode, 64-66
interface mode, 64
line mode, 64
privileged EXEC mode, 63-66, 80
clients
defining, 24
client/server model and application protocols, 148
cloud computing, 40
benefits of, 41
custom clouds, 41
hybrid clouds, 41
private clouds, 41
public clouds, 41
CNAME records, 155
collaboration
collaboration architectures, 46-47
collaboration tools
BYOD solutions, 37
defining, 8
commands
abbreviated commands/keywords, 73-74
context-sensitive help, 70
Ctrl-C and, 73
Ctrl-Shift-6 and, 73
Ctrl-Z and, 73
defining, 67
examination commands, 74
finding, 69
hot keys, 72
IOS command structure
abbreviated commands/keywords, 73-74
arguments, 67
command syntax check, 71
context-sensitive help, 70
Ctrl-C, 73
Ctrl-Shift-6, 73
Ctrl-Z, 73
examination commands, 74
hot keys, 72
keyboard shortcuts, 72
More prompt, 75
syntax, 68
Tab key, 72
Up/Down arrows, 73
keyboard shortcuts, 72
prompts
IOS operation, 64
More command prompt, 75
syntax
error messages, 71
syntax checks, 71
Tab key and, 72
undoing effects of, 79
Up/Down arrows and, 73
communication
defining, 10
messages
multiplexing, 124
segmenting, 124
networks
business, changes to, 9
communication, changes to, 7-8
computing, evolution of, 5
entertainment, changes to, 9-10
global communities, development of, 6, 10
non-time sensitive communication (QoS data classifications), 21
protocol suites, defining, 104
protocols, defining, 103
remote communication, ARP, 508-510
TCP/IP protocol suite communication process, 108-109
time sensitive communication (QoS data classifications), 21
undesirable communication (QoS data classifications), 21
unified communications, collaboration architectures, 47
computing, evolution of, 5
conceptualizing the Internet, 3, 27-28, 49
confidentiality (data), network security, 22
configuring
default gateways
hosts, static configuration of global unicast addresses, 325
routers
initial settings, 251
interface command, 324
static configuration of global unicast addresses, 324
verifying configurations, 253-254
terminals, configure terminal command, 78
text configurations, restoring, 87-88
confirming receipt of segments (TCP), 196-197
connection-based access, LAN topologies, 427
connection-oriented protocols, TCP, 178
connectionless communication, IP, 215
connectionless sessions, UDP, 201
connections (Internet), 32
business Internet connections
dedicated leased line, 34
DSL, 35
Metro Ethernet, 35
satellite, 35
remote Internet connections
cable, 33
cellular, 33
dial-up (telephone), 34
DSL, 33
satellite, 33
connectivity
testing via ping command
LAN, 345
local stacks, 344
loopbacks, 345
remote devices, 346
verifying
DAD, 343
testing end-to-end connectivity, 94
testing interface assignments, 94
testing loopback addresses, 93
testing PC-to-switch connectivity, 94
consoles
CLI environments, accessing via routers, 245
console ports
out-of-band access, 59
routers and, 244
controlled access, LAN topologies, 427-429
converged networks
developing, 14
planning, 14
traditional networks, 13
copper cable, 452
electrical hazards, 457
fiber optic cable versus, 471-472
fire hazards, 457
physical layer (OSI reference model), 442, 445
safety, 457
Ethernet crossover cable, 461
Ethernet straight through cable, 461
rollover cable, 462
testing, 464
types of, 461
copy run start command, router configuration, 251
copy running-config startup-config command, 85, 254
coverage areas (wireless media), 473
Crocker, Steve, RFC development, 119
crosstalk, 452
crypto key generate rsa general-keys modulus command, SSH and remote access, 576
CSMA (Carrier Sense Multiple Access), data collisions, 490
CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance)
data collisions, 492
media contention, 428
CSMA/CD (Carrier Sense Multiple Access/Collision Detection)
data collisions, 491
media contention, 428
Ctrl-C and IOS, 73
Ctrl-N, 73
Ctrl-P, 73
Ctrl-Shift-6 and IOS, 73
Ctrl-Z and IOS, 73
custom clouds (cloud computing), 41
customer collaboration architectures, 46
cut-through switching, 524
D
DAD (Duplicate Address Detection), 343
data
availability, network security, 23
collisions, 490
confidentiality, network security, 22
encapsulation, 123
de-encapsulation process, 127
encapsulation process, 126
Ethernet MAC sublayer, 489
PDU, 125
integrity, network security, 23
interception/theft, 43
Layer 2 frames, 416
loss of
network security, 560
TCP segments, 197
transmission
crosstalk, 452
EMI, 452
RFI, 452
Data field (Ethernet frames), 497
data link addresses
local resources (data delivery), accessing, 128
remote resources (data delivery), accessing, 132
data link layer (OSI reference model), 411-414
addressing, Ethernet MAC sublayer data encapsulation, 489
802.11 Wireless frames, 438-440
creating, 417
data, 416
formatting data for transmission, 416
LLC, 413
bus LAN topologies, 426
connection-based access, LAN topologies, 427
controlled access, LAN topologies, 427-429
CSMA/CA, 428
CSMA/CD, 428
extended star (hybrid) LAN topologies, 426
hub and spoke WAN topologies, 422
logical topologies, 420
media sharing, 420
mesh WAN topologies, 422
multi-access LAN topologies, 429
physical topologies, 420
point-to-point WAN topologies, 422-424
star LAN topologies, 425
topologies, 420
media access, 415
datagrams and UDP, 181, 201-202
decimal addressing, converting
binary notation to decimal addressing, 271
decimal addressing to binary notation, 272, 275-277, 290
decimal notation, positional notation, 268
dedicated leased line Internet connections, 34
default gateways, 91, 130, 226
configuring
troubleshooting, 257
delete vlan.dat command, 86
delimiting frames, Ethernet MAC sublayer data encapsulation, 489
description command, syntax of, 68
description text, configuring LAN interfaces, 253
Destination Address field (Ethernet frames), 497
destination data link addresses, IP packets, 128
destination IP addresses
destination IP address field (IPv4 packet headers), 220
destination MAC addresses, IP packets, 129, 132
destination networks, remote network routes, 235
destination ports, 183
Destination Unreachable messages (ICMP), 341
connectivity, verifying
testing interface assignments, 94
testing loopback addresses, 93
identifiers and EUI-64, 330
IP addresses
automatic configuration for end devices, 91-92
defining, 88
manual configuration for end devices, 91
names. See hostnames
security, 572
banners, 575
pass phrases, 574
SSH, 576
DHCP (Dynamic Host Configuration Protocol)
address pools, 293
application layer, 143, 158-160
automatic IP address configuration for end devices, 91
DHCPACK messages, 160
DHCPDISCOVER messages, 159-160
DHCPNAK messages, 160
DHCPOFFER messages, 160
DHCPREQUEST messages, 160
dynamic IPv4 addresses, assigning to hosts, 292
IP address conflicts, 92
ipconfig command, 293
DHCPv6 (Dynamic Host Configuration Protocol version 6)
global unicast addresses, 328-330
Interface ID, 330
stateless DHCPv6, 328
diagrams (topologies), 27
logical topology diagrams, 28
physical topology diagrams, 28
dial-up (telephone) Internet connections, 34
DIMM (dual in-line memory modules), DRAM, 242
direct connections, host packet forwarding, 226
directed broadcast IPv4 addressing, 295
directly connected routes
router packet forwarding, 232
routing table entries, 234, 235
disable command, navigating CLI between modes of operation, 65-66
disk arrays, 29. See also blocks
dispersion, 467
disruption of service and network security, 560
DIZ Ethernet standard, 107
DNS (Domain Name Service) protocol
application layer, 143, 155-157
nslookup command, 157
scalability, 157
DNS servers, 91
domain names, defining, 155
DoS (denial of service) attacks (security), 43, 565-566
dotted decimal addressing, converting
binary notation to decimal addressing, 271
decimal addressing to binary notation, 272, 275-277, 290
Down/Up arrows and IOS, 73
DRAM (Dynamic Random Access Memory), 242
drawing the Internet, 3, 27-28, 49
DS (Differentiated Services) field (IPv4 packet headers), 219
DSL (Digital Subscriber Line) Internet connections
ADSL, 35
business DSL, 35
remote user connections, 33
SDSL, 35
dual stacks, 309
duplex connectors, 469
duplex settings, LAN switches, 521-522
dynamic addressing
defining, 158
dynamic link-local addresses, 332-333
dynamic (private) ports and port addressing, 186
dynamic window sizes, 200
E
education, Internet’s changes to, 6-7
EH (Extension Headers), IPv6 packets, 225
EHWIC (Enhanced High-Speed WAN Interface Card) slots and routers, 244
EIA (Electronic Industries Alliance), 112
EIGRP (Enhanced Interior Gateway Routing Protocol), 107
electrical hazards, copper cable, 457
MDA, 152
MTA, 152
MUA, 152
POP and, 152
embedded IPv4 addresses, 320
EMI (Electromagnetic Interference), 452
employees, security breaches, 43
enable command, navigating CLI between modes of operation, 65
enable password command, 80
enable secret command, router configuration, 251
enable secret password command, 80
encapsulation
data, 123
de-encapsulation process, 127
encapsulation process, 126
PDU, 125
IPv6 packets, 223
network layer (OSI reference model), 214
encoding
frames (physical layer), 446-447
Manchester encoding, 447
NRZ, 447
encryption, 82
end devices
addressing, 213
clients, defining, 24
examples of, 24
host devices, 24
servers, 24
end finish errors, fiber optic cable, 470
end gap errors, fiber optic cable, 470
end-to-end connectivity, testing, 94
enterprise networks, 465
entertainment, Internet’s changes to, 9-10
entrance facilities, LAN cabling, 463
EoC (Ethernet over Copper), 35
ephemeral ports. See dynamic (private) ports and port addressing
erase command, 86
erase startup-config command, 86
errors
detecting, Ethernet MAC sublayer data encapsulation, 489
messages, command syntax, 71
RFC errata, 122
Ethernet, 486
ARP, 504
arp -a command, 513
ARP poisoning, 515
ARP spoofing, 515
maintaining ARP tables, 505
networking devices and ARP tables, 512
overhead, 514
remote communication and, 508-510
removing entries from ARP tables, 512
resolving IP addresses, 504
security, 515
show ip arp command, 512
development of, 107
DIX standard, 107
EoC, 35
Ethernet crossover cable, 461
Ethernet II, 495
Ethernet straight through cable, 461
fiber-optic Ethernet, 35
Data field, 497
Destination Address field, 497
Ethernet II, 495
FCS field, 497
Length field, 497
Preamble field, 496
SFD field, 496
Source Address field, 497
GigabitEthernet interfaces, subnetting IPv4 networks, 361
IEEE Ethernet standards, 488
LAN interfaces and routers, 246
LAN switches
Auto-MDIX, 522
cut-through switching, 524
fast-forward switching, 524
fragment-free switching, 524
full-duplex communication, 521-522
half-duplex communication, 521
Layer 2 LAN switches, 535
mdix auto interface command, 522
memory buffering, 525
modular configurations, 526-527, 531-534
ports, 516
store-and-forward switching, 523
ARP, 130
broadcast MAC addresses, 501
identifying, 500
ipconfig/all command, 500
MAC address structures, 492
multicast MAC addresses, 501
resolving via ARP, 504
unicast MAC addresses, 500
MAC sublayer, 488
data encapsulation, 489
Metro Ethernet Internet connections, 35
ports, 89
TCP/IP communication process, 109
EUI-64 (Extended Unique Identifier 64), unicast IPv6 addresses, 330-331
examination commands, 74
exec timeouts, device security, 575-576
exit command, navigating CLI from global configuration mode and submodes, 66
expandability (networks), 550
expectational acknowledgement, 196
experimental IPv4 addresses, 301
experimental RFC (Request for Comments), 122
extended ping command, 580-581
extended star (hybrid) topologies, 426
external QoS (Quality of Service), communication and, 12-13
extranet, defining, 32. See also Internet, intranet
F
Fast Ethernet SFP modules, 534
fast-forward switching, 524
fault tolerance, circuit-switched networks, 15
FCS (Frame Check Sequence) field, Ethernet frames, 497
fiber optic cable
components of, 466
end finish errors, 470
end gap errors, 470
misalignment errors, 470
network fiber-optic connectors, 468-469
physical layer (OSI reference model), 442
properties of, 465
SMF, 467
testing, 470
fiber optic Ethernet, 35
file sharing protocols
SAMBA, 163
SMB, 162
P2P, 8
finding commands, 69
FIN (finish) control flags, TCP three-way handshakes, 194
fire hazards, copper cable, 457
firewalls
dedicated firewall systems, 44
filtering, 44
network security, 570
first host addresses, IPv4 addressing, 284
fixed LAN switch configurations, 526-527
Catalyst 3560, 530
Catalyst 3750, 530
Catalyst Express 500, 528
Flash, 606
flash drives (USB), backing up/restoring IOS configuration files, 603-605
file systems, 598
flat network design, 357
flow control
TCP, 179
congestion, avoiding, 200
UDP, 180
flow label field, IPv6 packet headers, 224
FM (Frequency Modulation), 448
formatting IPv6 addresses
0 segments, 315
leading 0s, 313
preferred format, 312
fragmentation, 217
fragment-free switching, 524
IPv4 packet header fields, 220
frames, 412
delimiting, Ethernet MAC sublayer data encapsulation, 489
encoding, physical layer (OSI reference model), 446-447
Ethernet frames
Data field, 497
Destination Address field, 497
Ethernet II, 495
FCS field, 497
Length field, 497
Preamble field, 496
SFD field, 496
Source Address field, 497
Layer 2 frames, 431
802.11 Wireless frames, 438-440
creating, 417
data, 416
formatting data for transmission, 416
FTP (File Transfer Protocol)
application layer, 143
processes, 161
FTTH (Fiber To The Home), access networks, 465
full-duplex communication
point-to-point WAN topologies, 425
G
gateways
IPv4 host routing tables, 228
IPv6 route tables, 231
GET messages (HTTP), 151
.GIF (Graphics Interchange Format) files, presentation layer, 142
Gigabit Ethernet SFP modules, 534
GigabitEthernet interfaces, subnetting IPv4 networks, 361
global communities, development of, 6, 10
global configuration mode
IOS operation, 64
navigating from, 66
global routing prefixes, 323
global unicast addresses, 319, 322, 332
dynamic configuration
global routing prefixes, 323
reading, 324
static configuration
host configuration, 325
router configuration, 324
Subnet ID, 323
H
hacker attacks, 43
half-duplex communication
LAN switches, 521
point-to-point WAN topologies, 424
handshakes (three-way), TCP, 190
SYN segments, 192
hardware, defining, 24
header checksum field (IPv4 packet headers), 220
headers
IPv4 packets, 218
destination IP address field, 220
DS field, 219
header checksum field, 220
identification field, 220
IHL field, 220
protocol field, 219
sample headers, 221
source IP address field, 220
total length field, 220
TTL (Time to Live) field, 219
version field, 219
IPv6 packets
destination IP field, 225
EH, 225
flow label field, 224
hop limit field, 225
next header field, 225
payload length field, 225
sample headers, 225
source IP address field, 225
traffic class field, 224
version field, 224
hexadecimal numbering
Ethernet MAC addresses, 498
number conversions, 499
value representation, 499
hextet, 312
high importance to organization (QoS data classifications), 21
historic RFC (Request for Comments), 122
hops, 214
hop counts, 219
IPv6 hop limits
packet headers, 225
testing via traceroute command, 347-348
horizontal cabling, LAN cabling, 462
hostnames, 76
applying, example of, 78
configuring, 78
naming conventions, 77
hosts, 213
configuring
static configuration of global unicast addresses, 325
dynamic IPv4 addresses, assigning to hosts, 292-293
host addresses, IPv4 addressing, 282, 297
first host addresses, 284
last host addresses, 285
host commands, monitoring network performance
ipconfig command, 590
show cdp neighbors command, 592-594
show ip interface brief command, 594-595
Host Confirmation messages (ICMP), 340
host devices, defining, 24
host routing tables
host packet forwarding decisions, 226
static IPv4 addresses, assigning to hosts, 290-292
subnetting
formulas, 365
host calculations, 366-367, 371, 374, 377
hot keys, 72
HTML (Hypertext Markup Language), 108, 150
HTTP (Hypertext Transfer Protocol)
application layer, 143, 149-150
GET messages, 151
POST messages, 151
PUT messages, 151
segments, 105
TCP/IP communication process, 108
HTTPS (HTTP Secure), 151
hub and spoke topologies, 422
human networks, development of, 6, 10
hybrid (extended star) topologies, 426
hybrid clouds (cloud computing), 41
I
IAB (Internet Architecture Board), 110
IANA (Internet Assigned Numbers Authority), 113
IP address assignments, 304
port number assignments, 184
ICANN (Internet Corporation for Assigned Names and Numbers), 113
ICMP (Internet Control Message Protocol)
Destination Unreachable messages, 341
Host Confirmation messages, 340
Route Redirection messages, 341
Service Unreachable messages, 341
Time Exceeded messages, 341
I-D (Internet-Draft), RFC creation/validation process, 120
identification field (IPv4 packet headers), 220
IEEE (Institute of Electrical and Electronics Engineers), 111-112
data link layer standards, 418
Ethernet standards, 488
IEEE 802.3 standard, 107
IEEE 802.11 (WLAN), 474
AP, 475
NIC adapters, 475
standards, 476
IEEE 802.15 (WPAN), 474
IEEE 802.16 (WiMAX), 474
IETF (Internet Engineering Task Force), 110, 303
If column (IPv6 route tables), 231
IHL (Internet Header Length) field (IPv4 packet headers), 220
IM (instant messaging), 7. See also texting
image files (IOS) and routers, 247-249
IMAP (Internet Message Access Protocol), application layer, 143
IMP (Interface Message Processors), RFC development, 119
impconfig/all command, identifying Ethernet MAC addresses, 500
inband router interfaces, router connections, 245
informational RFC (Request for Comments), 121
information theft and network security, 22, 560
infrastructures (network)
components of, 23
end devices, 24
interfaces, 27
intermediary devices, 25
MAN, 29
NIC, 27
physical ports, 27
SAN, 29
small networks, 556
WLAN, 29
integrated firewalls, 570
integrity (data), network security, 23
interception/theft (data), 43
interface command, router configuration, 324
Interface ID
DHCPv6, 330
global unicast addresses, 323, 330
IPv6 subnetting, 400
randomly generated Interface ID, 331-332
interface lists, IPv4 host routing tables, 227
interface mode, IOS operation, 64
interface type-and-number command, configuring LAN interfaces, 252
interfaces
assigning, testing assignments, 94
defining, 27
IPv4 host routing tables, 228
small networks, 549
switch interfaces, verifying, 94
virtual interfaces
defining, 89
switch virtual interfaces, 90-91
VLAN interfaces, verifying assignments, 94
interference (wireless media), 473
intermediary devices. See network, devices
internal QoS (Quality of Service) and communication, 12-13
Internet. See also intranet, extranet
access technologies, 32
business, changes to, 9
BYOD, 38
accessibility, 37
collaboration tools, 37
defining, 36
QoS, 37
security, 37
cable Internet, coaxial cable, 457
communication, changes to, 7-8
connections, 32
business connections, 35
business Internet connections, 34-35
cable, 33
cellular, 33
dedicated leased line, 34
dial-up (telephone), 34
Metro Ethernet, 35
remote Internet connections, 33-34
satellite, 33
daily applications, 5
defining, 4
entertainment, changes to, 9-10
evolution of, 5
global communities, development of, 6, 10
IANA, IP address assignments, 304
IETF, classless addressing (CIDR), 303
Internet standards and RFC creation/validation process, 121
ISP, IP address assignments, 305-307
LAN and, 30
network administration organizations, 31
new trends
RIR, IP address assignments, 304-305
WAN and, 30
intranet, defining, 32. See also Internet, extranet
IOS (Internetwork Operating System), 56
accessing
AUX ports, 61
SSH protocol, 60
Telnet, 60
terminal emulation programs, 61
backups via
text capture (Tera Term), 600
text files, 600
USB flash drives, 603
CLI
CLI prompt, 63
command structure
abbreviated commands/keywords, 73-74
arguments, 67
command syntax check, 71
context-sensitive help, 70
Ctrl-C, 73
Ctrl-Shift-6, 73
Ctrl-Z, 73
examination commands, 74
hot keys, 72
keyboard shortcuts, 72
More prompt, 75
syntax, 68
Tab key, 72
Up/Down arrows, 73
configurations
restoring text configurations, 87-88
text capture, 87
connectivity, verifying
testing end-to-end connectivity, 94
testing interface assignments, 94
testing loopback addresses, 93
testing PC-to-switch connectivity, 94
context-sensitive help, 70
devices, securing access, 79-80
examination commands, 74
Flash file systems, 598
Flash memory, 57
functions, 58
hot keys, 72
image files and routers, 247-249
keyboard shortcuts, 72
modes of operation
command prompts, 64
global configuration mode, 64-66
interface mode, 64
line mode, 64
privileged EXEC mode, 63-66, 80
More prompt, 75
network performance, monitoring
ipconfig command, 590
show cdp neighbors command, 592-594
show ip interface brief command, 594-595
NVRAM file systems, 598
restoring via
text capture (Tera Term), 600
text configurations, 601
text files, 600
TFTP, 602
USB flash drives, 605
routers, 57
bootups, 247
functions, 58
security, passwords, 79
switch file systems, 598
configuring management addresses, 95
functions, 58
testing PC-to-switch connectivity, 94
text capture, configuration backups, 87
text configurations, restoring, 87-88
variations of, 57
virtual interfaces, switches, 90-91
IP (Internet Protocol), 106
characteristics of, 215
best effort (unreliable) delivery, 215, 216
connectionless communication, 215
IP addresses, 90
ARP, resolving IP addresses, 504
automatic configuration for end devices, 91, 92
conflicts, 92
default gateways, 91
DNS servers, 91
hosts, 213
ip address command and subnetting, 363
ip address subnet-mask command, configuring LAN interfaces, 253
manual configuration for end devices, 91
sockets, 184
testing end-to-end connectivity, 94
Windows IP configuration, verifying, 92
IP packets
data link frames, 109
destination data link addresses, 128
destination IP addresses, 127, 128, 131
destination MAC addresses, 129, 132
source data link addresses, 128
source IP addresses, 127, 128, 131
source MAC addresses, 129, 132
TCP/IP communication process, 109
ipconfig command, 92, 293, 590
ip domain-name command, SSH and remote access, 576
IP protocol suite, 107
IP telephony, small networks, 557
private addresses, 120
routing tables and RAM, 242
IPS (Intrusion Prevention Systems), 44
address depletion, 307
converting binary addresses to decimal, 271
converting decimal addresses to binary notation, 272, 275-277, 290
broadcast addresses, 283
broadcast addressing, 295
classful addressing
class A address space, 301
class B address space, 301
class C address space, 302
limits of, 303
classless addressing (CIDR), 303
dynamic addresses, assigning to hosts, 292-293
experimental addresses, 301
host addresses, 282
first host addresses, 284
last host addresses, 285
host portion, 278
host routing tables, 227
IANA address assignments, 304
IPv6 addressing and
dual stacks, 309
NAT64, 310
tunneling, 309
ISP address assignments, 305-307
LAN interfaces, configuring, 253
link local addresses, 300
loopbacks, 299
network portion, 278
packets
end-to-end connectivity, 222
hops, 214
improvements to packet handling, 222
Internet routing table expansion, 221
IP address depletion, 221
IP address space, 222
NAT, 222
payloads, 218
positional notation, 268
public addresses, 299
RIR address assignments, 304-305
router routing tables, 233, 236-239
static addresses, assigning to hosts, 290-292
subnet masks, 278
broadcast addresses, 283
first host addresses, 284
last host addresses, 285
prefix length, 279
subnetting
creating 100 subnets with a /16 prefix, 372-374
creating 1000 subnets with a /8 prefix, 375-376
determining subnet masks, 378-384
flat network design, 357
GigabitEthernet interfaces, 361
host calculation, 366-367, 371, 374, 377
ip address command, 363
reasons for subnetting, 357-358
connectivity via ping command, 344-346
paths via traceroute command, 347-348
TEST-NET addresses, 301
TTL fields, testing via traceroute command, 347-348
unicast addresses, 293-294, 320
verifying connectivity
address resolution, 343
DAD, 343
anycast addresses, 318
formatting addresses
0 segments, 315
leading 0s, 313
preferred format, 312
hexadecimal numbering, 311-312
hop limits, testing via traceroute command, 347-348
host routing tables
If column, 231
IANA address assignments, 304
IPv4 addressing and,
dual stacks, 309
NAT64, 310
tunneling, 309
ipv6 unicast-routing command, assigned multicast IPv6 addresses, 337
ISP address assignments, 305-307
multicast addresses, 318
assigned multicast addresses, 337
solicited-node multicast addresses, 338-339
need for, 307
packets
authentication, 222
benefits of, 222
encapsulation, 223
hops, 214
NAT, 222
privacy, 222
security, 222
prefix length, 318
RIR address assignments, 304-305
subnetting
Interface ID, 400
testing
connectivity via ping command, 344-346
paths via traceroute command, 347-348
unicast addresses, 317
embedded IPv4 addresses, 320
global unicast addresses, 319, 322-332
link-local addresses, 320-321, 332-334
loopbacks, 320
randomly generated Interface ID, 331-332
unique local addresses, 320
unspecified addresses, 320
verifying
IRTF (Internet Research Task Force), 110
ISN (Initial Sequence Numbers)
TCP segments, resequencing, 196
TCP three-way handshakes, 191
ISO (International Organization of Standards), 112, 418
ISOC (Internet Society), 110
ISP (Internet Service Providers), IP address assignments, 305-307
ITU (International Telecommunication Union), data link layer standards, 418
ITU-T (International Telecommunications Union-Telecommunication Standardization Sector), 113
J - K
job opportunities, 48
.JPEG (Joint Photographics Experts Group) files, presentation layer, 142
Kahn, Robert, TCP protocol suite development, 107
keyboard shortcuts, 72
keywords, abbreviated keywords/commands, 73-74
L
LAN (Local-Area Networks), 29-30
bus topologies, 426
connection-based access, 427
connectivity, testing via ping command, 345
Ethernet LAN interfaces and routers, 246
extended star (hybrid) topologies, 426
IEEE 802.3 standard, 107
interfaces, configuring, 252-253
multi-access topologies, 429
star topologies, 425
WLAN, 474
AP, 475
NIC adapters, 475
standards, 476
LAN adapters. See NIC
LAN switches
Auto-MDIX, 522
cut-through switching, 524
fast-forward switching, 524
Catalyst 3560, 530
Catalyst 3750, 530
Catalyst Express 500, 528
fragment-free switching, 524
full-duplex communication, 521-522
half-duplex communication, 521
Layer 2 LAN switches, 535
Layer 3 LAN switches, 535
Cisco Express Forwarding, 536-537
Layer 3 EtherChannel, 538
routed port interfaces, 538
SVI, 537
mdix auto interface command, 522
memory buffering, 525
modular configurations, 526-527
Catalyst 4900, 532
Catalyst 6500, 532
ports, 516
store-and-forward switching, 523
last host addresses and IPv4 addressing, 285
latency, 450
Layer 2 frames, 431
802.11 Wireless frames, 438-440
creating, 417
data, 416
formatting data for transmission, 416
Layer 2 LAN switches, 535
Layer 3 LAN switches, 535
Cisco Express Forwarding, 536-537
Layer 3 EtherChannel, 538
routed port interfaces, 538
SVI, 537
layered models, benefits of, 113
LC (Lucent Connectors), 468
learning, Internet’s changes to, 6-7
leased line Internet connections, 34
LED indicators, router connections, 245
legacy classful addressing
class A address space, 301
class B address space, 301
class C address space, 302
limits of, 303
Length field (Ethernet frames), 497
limited broadcast IPv4 addressing, 295
line mode, IOS operation, 64
link-local addresses, 300
dynamic link-local addresses, 332-333
dynamic link-local addresses, 332-333
static link-local addresses, 333-334
static link-local addresses, 333-334
LLC (Logical Link Control), 413
LLC sublayer (Ethernet), 487, 494
local default route, host packet forwarding, 226
local hosts, host packet forwarding, 226
local network route, host packet forwarding, 226
local resources (data delivery), accessing
communicating with devices on the same network, 128-129
data link addresses, 128
logical topologies
diagrams, 28
logical ring topologies, 431
MAC, 420
point-to-point topologies, 423
login local command, SSH and remote access, 576
long-haul networks, 465
loopbacks, 299
addresses, testing, 93
direct connections, 226
interfaces, 226
IPv6 addressing, 320
ping command, 345
losing segments (TCP), 197
M
MAC addresses, 128
MAC address structures, 492
Ethernet MAC addresses, 497
broadcast MAC addresses, 501
identifying, 500
ipconfig/all command, 500
multicast MAC addresses, 501
unicast MAC addresses, 500
IP addresses and, 502
end-to-end connectivity, 503
IP packets
destination MAC addresses, 129, 132
source MAC addresses, 129, 132
MAC (Media Access Control), 413-414, 419
CSMA/CA, 428
CSMA/CD, 428
Ethernet MAC sublayer, 488
CSMA, 490
CSMA/CA, 492
CSMA/CD, 491
data encapsulation, 489
broadcast MAC addresses, 501
destination MAC addresses, 129, 132
identifying, 500
ipconfig/all command, 500
multicast MAC addresses, 501
source MAC addresses, 129, 132
structures of, 492
unicast MAC addresses, 500
media sharing, 420
topologies, 420
bus LAN topologies, 426
connection-based access, LAN topologies, 427
controlled access, LAN topologies, 427-429
extended star (hybrid) LAN topologies, 426
hub and spoke WAN topologies, 422
logical topologies, 420
mesh WAN topologies, 422
multi-access LAN topologies, 429
physical topologies, 420
point-to-point WAN topologies, 422-424
star LAN topologies, 425
MAN (Metropolitan-Area Networks), 29
management addresses (switches), configuring, 95
management ports, router connections, 245
Manchester encoding, 447
MDA (Mail Delivery Agents) and email, 152
mdix auto interface command, 522
media
contention
CSMA/CA, 428
CSMA/CD, 428
defining, 25
network media, defining, 89
sharing, 420
memory
buffering via LAN switches, 525
DRAM
DIMM and, 242
routers and, 242
NVRAM
router bootups, 249
routers and, 242
RAM
ARP caches and, 242
DRAM, DIMM and, 242
DRAM, routers and, 242
IP routing tables and, 242
packet buffers and, 242
routers and, 241
running configuration (running-config) files and, 242
saving running configurations, 87
ROM, 242
routers and
Flash memory, 243
NVRAM, 242
RAM, 241
ROM, 242
mesh topologies, 422
messages
communication, elements of, 123-124
DHCPACK messages, 160
DHCPDISCOVER messages, 159-160
DHCPNAK messages, 160
DHCPOFFER messages, 160
DHCPREQUEST messages, 160
GET messages (HTTP), 151
multiplexing, 124
POST messages (HTTP), 151
PUT messages (HTTP), 151
segmenting, 124
Metcalfe, Bob, Ethernet development, 107
metrics
IPv4 host routing tables, 228
IPv6 route tables, 231
remote network routes, 235
Metro Ethernet Internet connections, 35
misalignment errors, fiber optic cable, 470
MMF (Multimode Fiber), 467-468
modular LAN switch configurations, 526-527
Catalyst 4900, 532
Catalyst 6500, 532
More prompt, 75
MOTD (Message Of The Day) banner, 83-84
moving data in networks
accessing
multiplexing messages, 124
segmenting messages, 124
.MPEG (Motion Picture Experts Group) files, presentation layer, 142
MTA (Mail Transfer Agents) and email, 152
MTU (Maximum Transmission Units), 217
MUAN (Mail User Agents), 152
multi-access topologies, 429
multicast addresses
IPv6 addresses, 318
assigned multicast addresses, 337
solicited-node multicast addresses, 338-339
MAC addresses, 501
conversations, transport layer (OSI reference model), 173
messages, 124
MX records, 155