N
naming devices. See hostnames
NAT (Network Address Translation)
IPv4 packets, 222
IPv6 packets, 222
NAT64 (Network Address Translation 64), 310
NDP (Neighbor Discovery Protocol)
Neighbor Advertisement messages, 343
Neighbor Solicitation messages, 343
Router Advertisement messages, 342
Router Solicitation messages, 342
netmasks, IPv4 host routing tables, 228
netstat command, TCP/UDP port addressing, 186
netstat –r command
IPv4 host routing tables, 227-228
IPv6 host routing tables, 231
LLC, 413
media access, 415
network access protocols, 106
components of, 445
fiber-optic cable, 442
functions, 445
throughput, 450
wireless media, 442
Network Basics Lab Manual, 3
network layer (OSI reference model)
de-encapsulation, 214
encapsulation, 214
end devices, addressing, 213
IP, characteristics of
best effort (unreliable) delivery, 215-216
connectionless communication, 215
IPv4, 214
end-to-end connectivity, 222
improvements to packet handling, 222
Internet routing table expansion, 221
IP address depletion, 221
IP address space, 222
NAT, 222
router routing tables, 233, 236-239
IPv6, 214
authentication, 222
benefits of, 222
encapsulation, 223
NAT, 222
privacy, 222
security, 222
PDU, 217
routers
AUX ports, 244
backpane, 244
branches, 241
computers, routers as, 240-241
configuring initial settings, 251
configuring LAN interfaces, 252-253
console ports, 244
CPU and OS, 241
EHWIC slots, 244
inside of, 243
LAN, 244
service providers, 241
verifying configurations, 253-254
WAN, 241
routing, 214
router routing tables, 232-240
networks
access networks, FTTH, 465
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, 144
TCP/IP protocol suite, 141-143, 149-150
architectures
Cisco Borderless Network Architectures, 46
Cisco Unified Data Center, 47
collaboration architectures, 46-47
defining, 45
baselines, determining, 581-582
business, changes to, 9
BYOD, 38
accessibility, 37
collaboration tools, 37
defining, 36
QoS, 37
security, 37
circuit-switched networks, 15-16
Cisco Borderless Network Architectures, 46
Cisco Unified Data Center, 47
clients, defining, 24
collaboration architectures, 46, 47
collaboration tools
BYOD solutions, 37
defining, 8
communication
business, 9
evolution of computing, 5
components of, 23
end devices, 24
interfaces, 27
intermediary devices, 25
media, 25
network representations, 26-28
NIC, 27
physical ports, 27
connectivity
testing via ping command, 344-346
converged networks
developing, 14
planning, 14
traditional networks, 13
data encapsulation, 123
de-encapsulation process, 127
encapsulation process, 126
PDU, 125
destinations
IPv6 route tables, 231
remote network routes, 235
devices
defining, 56
end devices, 24
enterprise networks, 465
entertainment, changes to, 9-10
expandability, 550
fiber-optic connectors, 468-469
hardware, defining, 24
host devices, defining, 24
hostnames, 76
applying, 78
configuring, 78
naming conventions, 77
human networks, development of, 6, 10
end devices, 24
interfaces, 27
intermediary devices, 25
MAN, 29
media, 25
network representations, 26-28
NIC, 27
physical ports, 27
SAN, 29
WLAN, 29
interfaces, defining, 27
intermediary devices, defining, 25
Internet administration organizations, 31
IP addresses
automatic configuration for end devices, 91-92
defining, 88
manual configuration for end devices, 91
sockets, 184
LAN, 29
configuring interfaces, 252-253
IEEE 802.3 standard, 107
Internet and, 30
testing connectivity via ping command, 345
long-haul networks, 465
MAC addresses, 128
ARP, 130
MAN, 29
mapping, topology diagrams, 27-28
moving data in
accessing local resources, 127-129
accessing remote resources, 130-132
multiplexing messages, 124
segmenting messages, 124
network architecture, defining, 15
network addresses
IPv4 addressing, 281, 289, 297
local resources (data delivery), accessing, 127-128
remote resources (data delivery), accessing, 131
Windows Calculator, 289
network applications
network-aware applications, defining, 144
small networks, 554
network protocols, 105
network representations, 26-28
network services, defining, 24
new trends
NIC, defining, 27
packet-switched networks
IP addresses, defining, 17
queues, 20
paths, testing via traceroute command, 347-348
performance, monitoring
ipconfig commands, 590
show cdp neighbors commands, 592-594
show ip interface brief command, 594-595
physical ports, defining, 27
platforms, networks as
presentation layer
.GIF files, 142
.JPEG files, 142
.MPEG files, 142
OSI reference model, 142
.PNG files, 142
QuickTime, 142
circuit-switched networks, 15
fault tolerance, 15
packet-switched networks, 17, 20
scalable networks, 19
supporting network architectures, 15
SAN, 29
security, 560
AAA network security services, 568-569
ACL, 44
adware, 43
antispyware, 44
antivirus software, 44
availability (data), 23
backups, 567
confidentiality (data), 22
data interception/theft, 43
data loss/manipulation, 560
dedicated firewall systems, 44
defining, 21
denial of service attacks, 43
disruption of service, 560
employees and security breaches, 43
firewall filtering, 44
firewalls, 570
hacker attacks, 43
information theft, 560
integrity (data), 23
IPS, 44
patches, 567
physical security, 561
RADIUS, 569
solutions, 44
spyware, 43
TACACS+, 569
updates, 567
upgrades, 567
VPN, 44
zero-day (zero-hour) attacks, 43
segmenting messages, 124
servers, defining, 24
session layer (OSI reference model), 142
small networks
application layer services, 554
design considerations, 552-553
infrastructures, 556
interfaces, 549
IP telephony, 557
network applications, 554
ports, 549
protocol requirements, 559
protocols, 555
real-time applications, 556-557
RTCP, 557
RTP, 557
scaling, 557
VoIP, 557
software, defining, 24
submarine networks, 465
telephone networks, 13
television networks, 13
topologies, 27
logical topology diagrams, 28
physical topology diagrams, 28
traditional networks, 13
transport layer
choosing protocols, 176
identifying applications, 172
multiplexing conversations, 173
OSI reference model, 170
port numbers, 172
reliability of, 174
role of, 170
segmenting/reassembling data, 172
separating multiple communications, 181
tracking individual conversations, 171-172
UDP, 171, 174-177, 180-187, 201-204
VLAN, verifying interface assignments, 94
VPN, 44
WAN, 29
Internet and, 30
AP, 475
NIC adapters, 475
standards, 476
WPAN, 474
next header field, IPv6 packet headers, 225
nibble boundaries, 401
defining, 27
NIC adapters, 475
no login command, 82
non-time sensitive communication (QoS data classifications), 21
no shutdown command, configuring LAN interfaces, 253
no switchport command, routed port Layer 3 switch configurations, 539
NRZ (Non-Return to Zero), 447
NS records, 155
nslookup command and DNS, 157
NVRAM (Non-Volatile Random Access Memory)
file systems, 598
O
octets
binary notation, 269-272, 275-277
decimal conversion, 271
open protocol standards, 109
optical fiber cable
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
OS (Operating Systems). See IOS
OSI Layer 3. See network layer (OSI reference model)
OSI (Open Systems Interconnection) reference model, 112-115
application interfaces, 145
application layer, 140
LLC, 413
media access, 415
network layer
addressing end devices, 213
de-encapsulation, 214
encapsulation, 214
IP, characteristics of, 215-218
PDU, 217
routers, 214
routers, configuring initial settings, 251
routers, configuring LAN interfaces, 252-253
routers, connecting to, 245-246
routers, default gateways, 254-256
routers, host routing tables, 226-232
routers, LAN interfaces, 245-246
routers, router routing tables, 232-240
routers, verifying configurations, 253-254
routers, WAN interfaces, 245-246
components of, 445
fiber-optic cable, 442
functions, 445
throughput, 450
wireless media, 442
presentation layer, 142
session layer, 142
TCP/IP protocol model comparisons to, 116-117
transport layer
choosing protocols, 176
identifying applications, 172
multiplexing conversations, 173
port numbers, 172
reliability of, 174
role of, 170
segmenting/reassembling data, 172
separating multiple communications, 181
tracking individual conversations, 171-172
UDP, 171, 174-177, 180-187, 201-204
OUI (Organizationally Unique Identifiers) and EUI-64, 330
outgoing interfaces, remote network routes, 236
out-of-band access, defining, 59
overhead
ARP problems, 514
TCP, 189
UDP, 201
P
application protocols and, 145-147
file sharing, 8
packets
best effort (unreliable) delivery, IP, 215-216
filtering (firewalls), network security, 570
hops, 214
host packet forwarding decisions, 226
IP packets
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
IPv4 packets
end-to-end connectivity, 222
improvements to packet handling, 222
Internet routing table expansion, 221
IP address depletion, 221
NAT, 222
payloads, 218
IPv6 packets
authentication, 222
benefits of, 222
encapsulation, 223
IP address space, 222
NAT, 222
privacy, 222
security, 222
MTU, 217
network security, 570
next-hop addressing, 236
packet buffers and RAM, 242
packet-switched networks
IP addresses, defining, 17
queues, 20
router packet forwarding decisions
directly connected routes, 232-235
remote network routes, 235
remote routes, 232
routing
router routing tables, 232-240
PARC (Palo Alto Research Center), Xerox, Ethernet development, 107
pass phrases, device security, 574
password command, router configuration, 251
passwords
best practices, 79
choosing, 80
enable password command, 80
enable secret password command, 80
encryption, 82
service password-encryption command, 82
vty, 81
patches, network security, 567
paths, testing via traceroute command, 347-348
payloads
IPv4 packets, 218
payload length field, IPv6 packet headers, 225
PC connectivity, testing, 94
PCM (Pulse-Code Modulation), 449
PDU (Protocol Data Units)
data encapsulation, 125
MTU, 217
network layer (OSI reference model), 217
TCP, 195
TCP/UDP segmentation, 187
UDP. See datagrams and UDP
peer-to-peer file sharing. See P2P (Peer-to-Peer) networks, file sharing
performance (networks), monitoring
host commands
ipconfig command, 590
show cdp neighbors command, 592-594
show ip interface brief command, 594-595
IOS commands
ipconfig command, 590
show cdp neighbors command, 592-594
show ip interface brief command, 594-595
ping command
extended ping command, 580-581
show commands, 585
viewing router settings, 588-589
viewing switch settings, 589
personal firewalls, 570
physical addresses. See MAC addresses
physical layer (OSI reference model), 411, 441
components of, 445
fiber-optic cable, 442
functions, 445
throughput, 450
wireless media, 442
physical ports, defining, 27
physical security (networks), 561
physical topologies, 28
MAC, 420
point-to-point topologies, 422-423
ping command, 297
connectivity, testing
LAN, 345
local stacks, 344
loopbacks, 345
remote devices, 346
loopback addresses, testing, 93
network performance, monitoring
extended ping command, 580-581
syntax of, 68
testing PC-to-switch connectivity, 94
verifying
IPv6 address configuration, 336
router configuration, 253
planning converged networks, 14
platforms, networks as
converged networks
developing, 14
planning, 14
traditional networks, 13
reliable networks
circuit-switched, connection-oriented networks, 16
circuit-switched networks, 15
fault tolerance, 15
packet-switched networks, 17, 20
scalable networks, 19
supporting network architectures, 15
play (entertainment), Internet’s changes to, 9-10
.PNG (Portal Network Graphics) files, presentation layer, 142
podcasting, defining, 8
point-to-point topologies
full-duplex communication, 425
half-duplex communication, 424
logical topologies, 423
POP (Post Office Protocol)
email and, 152
ports
addressing
destination ports, 183
dynamic (private) ports, 186
IANA port number assignments, 184
socket pairs, 184
sockets, 184
source ports, 183
TCP/UDP common ports, 186
well-known ports, 184
AUX ports
CLI environments, accessing via routers, 245
IOS access, 61
routers and, 244
console ports
out-of-band access, 59
routers and, 244
Ethernet ports, 89
LAN switches, 516
management ports, router connections, 245
physical ports, defining, 27
port-based memory buffering, 525
port numbers, 172
dynamic (private) ports, 186
IANA assignments, 184
sockets, 184
TCP, 182
UDP, 182
well-known ports, 184
private (dynamic) ports and port addressing, 186
SFP ports, modular LAN switch configurations, 533-534
small networks, 549
USB ports and Cisco routers, 602-603
positional notation, 268
POST (Power On Self Test)
POST messages (HTTP), 151
router bootup process, 248
power cycles, defining, 57
PPP (Point-to-Point Protocol), PPP frames, 437-438
Preamble field (Ethernet frames), 496
presentation layer
.GIF files, 142
.JPEG files, 142
.MPEG files, 142
OSI reference model, 142
.PNG files, 142
QuickTime, 142
priority queuing, packet-switched networks, 20
privacy, IPv6 packets, 222
private clouds (cloud computing), 41
private (dynamic) ports and port addressing, 186
private IP addresses, 120
private IPv4 addresses, 298-299
privileged EXEC mode
defining, 63
IOS operation, 63
securing access, 80
user EXEC mode, moving between, 65-66
processes
defining, 144
FTP processes, 161
proposed standards, RFC creation/validation process, 120
proprietary protocols, 107
protocol suites
defining, 104
IP, 107
OSI reference model, 112
application interfaces, 145
application layer, 140
presentation layer, 142
session layer, 142
TCP/IP protocol model comparisons to, 116-117
application layer, 141-143, 149-150
communication process, 108-109
development of, 107
OSI reference model comparisons to, 117
protocols
analysis, small networks, 558-559
application layer protocols, 105, 141
BOOTP, 143
client/server model and, 148
ARP, MAC addresses, 130
BOOTP, 143
connection-oriented protocols, 178
defining, 103
DHCP
application layer, 143, 158-160
DHCPACK messages, 160
DHCPDISCOVER messages, 159-160
DHCPNAK messages, 160
DHCPOFFER messages, 160
DHCPREQUEST messages, 160
DNS
application layer, 143, 155-157
nslookup command, 157
scalability, 157
EIGRP, 107
Ethernet
development of, 107
TCP/IP communication process, 109
file sharing protocols
SAMBA, 163
SMB, 162
HTTP
application layer, 143, 149-150
GET messages, 151
HTML and, 150
HTTPS and, 151
POST messages, 151
PUT messages, 151
segments, 105
TCP/IP communication process, 108
HTTPS, 151
IMAP, application layer, 143
IP, 106
IP packets
defining, 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
network access protocols, 106
network protocols, 105
open standards, 109
POP
email and, 152
proprietary protocols, 107
protocol field (IPv4 packet headers), 219
requirements, small networks, 559
RFC, 118
BCP, 121
creation/validation process, 120-121
development of, 119
errors in, 122
experimental RFC, 122
historic RFC, 122
informational RFC, 121
Internet standards, 121
private addresses, 120
RFC 1918, 119
sample of, 119
SAMBA, 163
SMB, 162
SMTP
application layer, 143, 152-154
standards-based protocols, 106
standards organizations
EIA, 112
IAB, 110
IANA, 113
ICANN, 113
IETF, 110
IRTF, 110
ISO, 112
ISOC, 110
ITU-T, 113
TIA, 112
stateful protocols, 179
stateless protocols, 181
applications using TCP, 203
establishing connections, 189, 190, 191
establishing sessions, 178
PDU, 195
port numbers, 182
reliability, 178, 188, 195-200
role of, 179
SACK, 198
same-order delivery, 179
segmentation, 187
server processes, 189
TCP/IP communication process, 108
UDP versus, 177
Telnet, application layer, 143
TFTP, application layer, 143
transport layer protocol, 105
applications using TCP, 203-204
client requests, 202
connectionless sessions, 201
datagrams, 181
features of, 180
flow control, 180
overhead, 201
port numbers, 182
reassembling datagrams, 201-202
reliability, 201
role of, 181
segmentation, 187
segments, 181
server processes/requests, 202
TCP versus, 177
public clouds (cloud computing), 41
public IPv4 addresses, 299
PUT messages (HTTP), 151
Q
QoS (Quality of Service)
BYOD solutions, 37
communication and
queues (priority) and packet-switched networks, 20
QuickTime, presentation layer, 142
R
RADIUS (Remote Authentication Dial-In User Service), network security network security, 569
radix (positional notation), 268
RAM (Random Access Memory)
ARP caches and, 242
DRAM, 242
IP routing tables and, 242
packet buffers and, 242
routers and, 241
running configuration (running-confg) files and, 87, 242
randomly generated Interface ID, unicast IPv6 addresses, 331-332
real-time applications, small networks, 556-557
reassembling datagrams (UDP), 201-202
receiving segments, TCP, 196-197
reconnaissance attacks (security), 565
recreation, Internet’s changes to, 9-10
reducing window sizes, 200
redundancy, small networks, 551-552
reference models
layered models, benefits of, 113
application interfaces, 145
application layer, 140
presentation layer, 142
session layer, 142
TCP/IP protocol model comparisons to, 116-117
registered ports, port addressing and, 185-186
reliable networks
circuit-switched networks, 15-16
fault tolerance, 15
packet-switched networks
IP addresses, defining, 17
queues, 20
scalable networks, 19
support network architectures, 15
reload command, 85
remote communication, ARP, 508-510
remote devices, testing connectivity via ping command, 346
remote hosts, host packet forwarding, 226
remote Internet connections
cable, 33
cellular, 33
dial-up (telephone), 34
DSL, 33
satellite, 33
remote network routes, routing table entries, 235
remote resources (data delivery), accessing
communicating with devices on remote networks, 131-132
data link addresses, 132
default gateways, 130
network addresses, 131
remote routes, router packet forwarding, 232
representations (network), 26-28
resequencing segments, TCP, 195
restoring IOS configuration files
text capture (Tera Term), 600
text configurations, 601
text files, 600
TFTP, 602
retransmitting TCP segments, 198
RFC (Request for Comments), 118
BCP, 121
creation/validation process, 120-121
development of, 119
EIGRP, 107
errors in, 122
experimental RFC, 122
historic RFC, 122
informational RFC, 121
Internet standards, 121
private addresses, 120
RFC 1918, 119
sample of, 119
RFI (Radio Frequency Interference), 452
RIR (Regional Internet Registries), IP address assignments, 304-305
rollover cable, 462
ROM (Read Only Memory) and routers, 242
routers
AUX ports, 244
backpane, 244
bootups
bootset files, 247
POST, 248
startup configuration files, 249
TFTP servers, 249
branches, 241
Cisco routers and USB ports, 602-603
computers, routers as, 240-241
configuring
initial settings, 251
interface command, 324
static configuration of global unicast addresses, 324
verifying configurations, 253-254
console ports, 244
CPU and OS
Flash memory, 243
NVRAM, 242
RAM, 241
ROM, 242
default gateways, 130, 254-256
EHWIC slots, 244
hops, 214
host routing tables
host packet forwarding decisions, 226
inside of, 243
interfaces, verifying, 594-595
IOS, 57
router functions, 58
network layer (OSI reference model), 214
reloading, 257
route print command, IPv4 host routing tables, 227
Route Redirection messages (ICMP), 341
route sources, remote network routes, 235
route timestamps, remote network routes, 236
routed port interfaces, Layer 3 LAN switches, 538
Router Advertisement messages (NDP), 342
router routing tables, 240
directly connected routing table entries, 234-235
next-hop addressing, 236
remote network routing table entries, 235
router packet forwarding decisions, 232
Router Solicitation messages (NDP), 342
security, 572
service providers, 241
show version command, 75
startup configuration files, 247-249
RTCP (Real-Time Transport Control Protocol), small networks, 557
RTP (Real-Time Transport Protocol), small networks, 557
RTT (Round-Trip Time), 347
running configuration (running-config) files and RAM, 242
S
SACK (Selective Acknowledgements), TCP segments, 198
SAMBA protocol, 163
SAN (Storage Area Networks), 29
satellite Internet connections, 33-35
scalability
defining, 19
DNS, 157
SC (Subscriber Connectors), 468
SDSL (Symmetric Digital Subscriber Line) Internet connections, 35
security
AAA network security services
accounting, 569
authorization, 569
ACL, 44
adware, 43
antispyware, 44
antivirus software, 44
ARP problems, 515
attacks, 564
access attacks, 565
defining, 562
reconnaissance attacks, 565
backups, 567
BYOD solutions, 37
data interception/theft, 43
data loss/manipulation, 560
defining, 21
denial of service attacks, 43
devices, 572
banners, 575
pass phrases, 574
SSH, 576
disruption of service, 560
employees and security breaches, 43
encryption, 82
hacker attacks, 43
IPS, 44
IPv6 packets, 222
passwords
best practices, 79
choosing, 80
encryption, 82
vty, 81
patches, 567
physical security, 561
privileged EXEC mode access, 80
RADIUS, 569
requirements (data)
availability, 23
confidentiality, 22
integrity, 23
routers, 572
security passwords min-length command, device command, 575
service password-encryption command, 82
solutions, 44
spyware, 43
TACACS+, 569
updates, 567
upgrades, 567
VPN, 44
wireless media, 473
zero-day (zero-hour) attacks, 43
segments (data), 124
HTTP messages, 105
SYN segments, TCP three-way handshakes, 192
confirming receipt of segments, 196-197
losing, 197
resequencing segments, 195
retransmitting, 198
transport layer (OSI reference model), 172
sequence numbers
ISN, TCP three-way handshakes, 191
TCP segments, confirming receipt of, 196
serial WAN interfaces and routers, 246
servers
client/server model and application protocols, 148
defining, 24
firewalls, 570
TFTP servers, router bootups, 249
UDP, 202
services
defining, 24
disruption of (network security), 560
routers and service providers, 241
service password-encryption command, 82
device security, 574
router configuration, 251
Service Unreachable messages (ICMP), 341
session layer, OSI reference model, 142
SFD (Start of Frame Delimiter) field, Ethernet frames, 496
SFP (small form-factor pluggable) ports, modular LAN switch configurations, 533-534
sharing
file sharing protocols
SAMBA, 163
SMB, 162
media, 420
memory buffering, 525
P2P files, 8
shortcuts (keyboard), 72
show cdp neighbors command, 592-594
network performance, monitoring, 585
viewing router settings, 588-589
viewing switch settings, 589
show file systems command, router file systems, 597
show interface command, verifying IPv6 address configuration, 334
show ip arp command, ARP tables, 512
show ip interface brief command, 94, 253, 594-595
show ip route command, 233, 253
show ipv6 interface brief command, verifying IPv6 address configuration, 334
show ipv6 route command, verifying IPv6 address configuration, 335
show run command, router configuration, 251
show running-config command, 85, 87
show startup-config command, 87
show version command, 75, 249-250
signal attenuation, 452
signaling method, physical layer (OSI reference model), 447-449
SLAAC (Stateless Address Autoconfiguration), global unicast addresses, 327-328
slash notation, prefix length, 279
small networks
application layer services, 554
design considerations, 552-553
devices, selecting, 548
cost, 549
expandibility, 550
interfaces, 549
operating system features and services, 550
ports, 549
speed, 549
infrastructures, 556
interfaces, 549
IP telephony, 557
network applications, 554
ports, 549
protocols, 555
requirements, 559
real-time applications, 556-557
RTCP, 557
RTP, 557
scaling, 557
VoIP, 557
SMB (Server Message Blocks), 162
SMF (Single-Mode Fiber), 467
SMTP (Simple Mail Transfer Protocol), 143, 152-154
social media, defining, 8
socket pairs, 184
sockets, 184
software, defining, 24
solicited-node IPv6 multicast addresses, 338-339
Source Address field (Ethernet frames), 497
source data link addresses, IP packets, 128
source IP addresses
IP packets, 127
communicating with devices on remote networks, 131
communicating with devices on the same network, 128
source IP address field
IPv4 packet headers, 220
IPv6 packet headers, 225
source MAC addresses, IP packets
communicating with devices on remote networks, 132
communicating with devices on the same network, 129
source ports and port addressing, 183
SPI (Stateful Packet Inspection), firewalls and network security, 570
spyware, 43
SSH (Secure Shell)
CLI environments, accessing via routers, 245
device security, 576
IOS access, 60
remote access, 576
ST (Straight-Tip) connectors, 468
standards
Internet standards, 121
proposed standards, RFC creation/validation process, 120
RFC, 118
BCP, 121
creation/validation process, 120-121
development of, 119
errors in, 122
experimental RFC, 122
historic RFC, 122
informational RFC, 121
Internet standards, 121
private addresses, 120
RFC 1918, 119
sample of, 119
standards-based protocols, 106
standards organizations
EIA, 112
IAB, 110
IANA, 113
ICANN, 113
IETF, 110
IRTF, 110
ISO, 112
ISOC, 110
ITU-T, 113
open protocol standards, 109
TIA, 112
star topologies, 425
startup configuration files and routers, 247-249
stateful protocols, TCP, 179
stateless DHCPv6 (Dynamic Host Configuration Protocol version 6), 328
stateless protocols, UDP, 181
static addressing
defining, 158
static IP addresses, assigning to hosts, 290-292
static link-local addresses, 333-334
store-and-forward switching, 523
STP (Shielded Twisted Pair) cable, 453-455
submarine networks, 465
subnetting, 356
defining, 358
formulas
hosts, 365
subnets, 364
host calculation
creating 8 subnets, 371
creating 100 subnets with a /16 prefix, 374
creating 1000 subnets with a /8 prefix, 377
IPv4 addressing, 278
broadcast addresses, 283
first host addresses, 284
last host addresses, 285
prefix length, 279
IPv4 networks
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
ip address command, 363
reasons for subnetting, 357-358
Subnet ID, global unicast addresses, 323
IPv6 networks
Interface ID, 400
LAN interfaces, configuring, 253
nibble boundaries, 401
subnet masks and IPv4 networks
SVI (switch virtual interfaces), Layer 3 LAN switches, 537
switch file systems, 598
switches, 76
Catalyst 2960 switches, 529, 530
Catalyst 3560 switches, 530
Catalyst 3750 switches, 530
Catalyst 4500 switches, 531, 532
Catalyst 4900 switches, 532
Catalyst 6500 switches, 532
Catalyst Express 500 switches, 528
Cisco Catalyst switches, 61
default gateways, configuring, 255-256
interfaces, verifying, 94, 595
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
management addresses, configuring, 95
PC-to-switch connectivity, testing, 94
reloading, 257
settings, viewing, 589
show version command, 75
virtual interfaces, configuring, 90-91
synchronous data signals, 448
SYN control flags, TCP three-way handshakes, 191-193
SYN segments, TCP three-way handshakes, 192
syntax
error messages, 71
Syntax Checker, global unicast addresses, 326
T
Tab key and IOS, 72
TACACS+ network security, 569
TCP (Transmission Control Protocol), 105, 171, 175
applications using TCP, 203
connections, establishing, 189-191
flow control, 179
avoiding congestion, 200
PDU, 195
ports
numbers, 182
confirming receipt of segments, 196-197
losing segments, 197
resequencing segments, 195
retransmitting segments, 198
role of, 179
SACK, 198
same-order delivery, 179
confirming receipt of segments, 196-197
losing, 197
retransmitting, 198
server processes, 189
sessions
establishing, 178
TCP/IP communication process, 108
three-way handshakes, 190
SYN segments, 192
UDP versus, 177
TCP/IP (Transmission Control Protocol/Internet Protocol) protocol suite, 106, 114-116
application layer, 141
BOOTP, 143
FTP, 143
IMAP, 143
POP, 143
SMTP, 143
Telnet protocol, 143
TFTP, 143
communication process, 108-109
development of, 107
OSI reference model comparisons to, 117
telecommunications rooms, LAN cabling, 463
telephone (dial-up) Internet connections, 34
telephone networks, 13
TelePresence, collaboration architectures, 46
television networks, 13
Telnet
CLI environments, accessing via routers, 245
defining, 60
IOS access, 60
Telnet protocol, application layer, 143
terminal emulation programs, IOS access, 61
testing
connectivity via ping command, 344-346
copper cable, 464
fiber optic cable, 470
paths, traceroute command, 347-348
TEST-NET addresses, 301
text
captures
configuration backups, 87
IOS configuration files, restoring (Tera Term), 600
configurations, restoring, 87-88, 600-601
text files, restoring IOS configuration files, 600
TFTP (Trivial File Transfer Protocol)
application layer, 143
IOS configuration files
restoring, 602
servers, router bootups, 249
theft
data interception/theft, 43
identity theft, 43
threats (security), defining, 562
three-way handshakes, TCP, 190
SYN control flags, 191, 192, 193
SYN segments, 192
throughput, physical layer (OSI reference model), 450
TIA (Telecommunications Industry Association), 112
Time Exceeded messages (ICMP), 341
time sensitive communication (QoS data classifications), 21
timestamps (route), remote network routes, 236
token passing, 431
topologies
bus topologies, 426
diagrams, 28
extended star (hybrid) topologies, 426
hub and spoke topologies, 422
LAN topologies
bus topologies, 426
connection-based access, 427
extended star (hybrid) topologies, 426
multi-access topologies, 429
star topologies, 425
logical topologies
diagrams, 28
MAC, 420
point-to-point topologies, 423
mesh topologies, 422
multi-access topologies, 429
physical topologies
diagrams, 28
MAC, 420
point-to-point topologies, 422-423
point-to-point topologies
full-duplex communication, 425
half-duplex communication, 424
logical topologies, 423
star topologies, 425
WAN topologies
hub and spoke topologies, 422
mesh topologies, 422
point-to-point topologies, 422-425
ToS (Type of Service) field. See DS (Differentiated Services) field (IPv4 packet headers)
total internal reflection, 466
total length field (IPv4 packet headers), 220
traceroute command
network performance, monitoring, 583-584
paths, testing
RTT, 347
syntax of, 68
TTL fields, 219
traditional networks, 13
traffic class field, IPv6 packet headers, 224
trailers (Layer 2 frames), 416, 435
translation (NAT64), 310
transport input ssh command, SSH and remote access, 576
transport layer
identifying applications, 172
individual conversations, tracking, 171-172
multiple communications, separating, 181
multiplexing conversations, 173
OSI reference model, 170
port numbers, 172
protocols, choosing, 176
reliability of, 174
role of, 170
segmenting/reassembling data, 172
applications using TCP, 203
establishing connections, 189-191
establishing sessions, 178
PDU, 195
port numbers, 182
reliability, 178, 188, 195-200
role of, 179
SACK, 198
same-order delivery, 179
segmentation, 187
server processes, 189
UDP versus, 177
transport layer protocol, 105
applications using TCP, 203-204
client requests, 202
connectionless sessions, 201
datagrams, 181
features of, 180
flow control, 180
overhead, 201
port numbers, 182
reassembling datagrams, 201-202
reliability, 201
role of, 181
segmentation, 187
segments, 181
server processes/requests, 202
TCP versus, 177
TTL (Time to Live) field (IPv4 packet headers), 219, 347-348
tunneling, 309
U
UCLA, RFC development, 119
UDP (User Datagram Protocol), 171, 174-176
applications using TCP, 203-204
clients
processes, 202
requests, 202
connectionless sessions, 201
features of, 180
flow control, 180
overhead, 201
port numbers, 182
reliability, 201
role of, 181
segmentation, 187
segments, 181
servers
processes, 202
requests, 202
TCP versus, 177
undesirable communication (QoS data classifications), 21
undoing, command effects, 79
unicast IPv4 addresses, 293-294
embedded IPv4 addresses, 320
unicast IPv6 addresses, 317-318
embedded IPv4 addresses, 320
global unicast addresses, 319, 322, 332
dynamic configuration, 327-330
global routing prefixes, 323
host configuration, 325
reading, 324
router configuration, 324
Subnet ID, 323
dynamic link-local addresses, 332-333
static link-local addresses, 333-334
loopbacks, 320
randomly generated Interface ID, 331-332
unique local addresses, 320
unspecified addresses, 320
unicast MAC addresses, 500
unified communications, collaboration architectures, 47
unique local addresses, IPv6 addressing, 320
unreliable (best effort) delivery, IP, 215-216
unspecified addresses, IPv6 addressing, 320
updates, network security, 567
Up/Down arrows and IOS, 73
upgrades, network security, 567
URL filtering (firewalls), network security, 570
USB (Universal Serial Bus)
USB flash drives, IOS configuration files
backups, 603
restoring, 605
USB ports and Cisco routers, 602-603
user EXEC mode
defining, 63
IOS operation, 63
privileged EXEC mode, moving between, 65-66
username secret command, SSH and remote access, 576
UTP (unshielded twisted pair) cable, 453-454
Ethernet crossover cable, 461
Ethernet straight through cable, 461
rollover cable, 462
testing, 464
types of, 461
V
verifying
connectivity
address resolution, 343
DAD, 343
testing end-to-end connectivity, 94
testing interface assignments, 94
testing loopback addresses, 93
testing PC-to-switch connectivity, 94
dynamic IPv4 addresses, 293
IPv6 address configuration, 334-337
router configurations, 253
version field
IPv4 packet headers, 219
IPv6 packet headers, 224
viewing network traffic, 133
virtual circuits, 423
virtual interfaces (switches), configuring, 89-91
VLAN (Virtual Local-Area Network) interfaces, verifying assignments, 94
VLSM (Variable Length Subnet Masks), 386-393, 397
VoIP (Voice over Internet Protocol), small networks, 557
VPN (Virtual Private Networks), 44
vty
login local command, 576
SSH and remote access, 576
transport input ssh command, 576
vty password, 81
vulnerabilities (security), 562-564
W
WAN (Wide-Area Networks), 29
hub and spoke topologies, 422
Internet and, 30
mesh topologies, 422
point-to-point topologies
full-duplex communication, 425
half-duplex communication, 424
logical topologies, 423
serial WAN interfaces and routers, 246
weblogs (blogs), 8
Wikipedia, 8
wikis, defining, 8
WiMAX (Worldwide Interoperability for Microwave Access), 474
window size
dynamic window sizes, 200
reducing, 200
Windows Calculator, network addresses, 289
wireless devices, coaxial cable, 456
Wireless frames (802.11), 438-440
wireless media
coverage areas, 473
interference, 473
physical layer (OSI reference model), 442
properties of, 472
security, 473
types of, 473
WiMAX, 474
AP, 475
NIC adapters, 475
standards, 476
work areas and LAN cabling, 462
WPAN (Wireless Personal Area Networks), 474
X - Y - Z
Xerox, Ethernet development, 107
zero-day (zero-hour) attacks, 43