All Course Flashcards
1
Q
Application Layer (7th layer)
A
Interacts with application programs that incorporate a communication component such as your Internet
browser and email (provides user interface)
2
Q
Bus Topology
A
The computers share the media (coaxial cable) for data transmission
3
Q
CAT6 (category 6)
A
Twisted-pair cables capable of carrying up to 1000Mbps (1 gigabit) of data up to a length of 100
meters
4
Q
Crossover
A
Transmit and receive signal pairs are crossed to properly align the transmit signal on one device with
the receive signal on the other device
5
Q
CSMA/CD
A
Carrier sense multiple access with collision detection is the Ethernet LAN media-access method (used to
prevent collisions in wired Ethernet networks) Used in wireless networks for to reduce collisions.
6
Q
Data Link Layer (2nd layer)
A
Layer of the OSI reference model that handles error recovery, flow control (synchronization), and
sequencing (controls which terminals are sending and receiving. Media access is controlled by the Data Link Layer
7
Q
Deterministic
A
Access to the network is provided at fixed time intervals
8
Q
Ethernet, Physical, Hardware, or Adapter Address
A
Other names for MAC address
9
Q
Firewall Protection
A
Used to prevent unauthorized access to your network
10
Q
Host Address
A
The portion of the IP address that defines the location of the networking device connected to the network;
also called the host address - Same as host number
11
Q
Hotspots
A
A limited geographic area that provides wireless access for the public
12
Q
Hub
A
Broadcasts the data it receives to all devices connected to its ports… it is possible for network devices to pick up a data intended for a different device… considered
a multiport repeater
13
Q
IANA
A
The Internet Assigned Numbers Authority is the agency that assigns IP addresses to computer networks
14
Q
ICMP
A
Internet Control Message Protocol (perform diagnostics, report errors, control the flow of data in
the network)
15
Q
IEEE
A
Institute of Electrical and Electronics Engineers, one of the major standard-setting bodies for technological
development
16
Q
Intranet
A
An internal network that provides file and resource sharing but ifs not accessed from the Internet
17
Q
IP Address
A
Unique 32-bit address that identifies on which network the computer is located as well as
differentiates the computer from all other devices on the same network; they are logical addresses and can be found using the ipconfig/all command
18
Q
IP Internetwork
A
A network that uses IP addressing for identifying devices connected to the network
19
Q
ipconfig/all
A
Enables the MAC address information to be displayed
from the command prompt
20
Q
ISP
A
Internet service provider
21
Q
Link Integrity Test
A
Protocol used to verify that a communication link between two Ethernet devices has been established
22
Q
Link Light
A
Indicates that the transmit and receive pairs are properly aligned
23
Q
Link Pulses
A
Sent by each of the connected devices via the twisted- pair cables when data is not being transmitted to
indicate that the link is still up
24
Q
Local Area Network (LAN)
A
Network of users that share computer resources in a limited area
25
MAC Address
A unique 6-byte address assigned by the vendor of the network interface card; A MAC address has two
portions. The OUI is comprised of the first 6 digits and the last half is assigned by the manufacturer.
26
Mbps
Megabits per second
27
Mesh Topology
All networking devices are directly connected to each other (fault tolerant; stations can still communicate if
some segments go down)
28
Multiport Repeater
Another name for a hub
29
Network Address Translation (NAT)
Translates the private IP address to a public address for routing over the Internet
30
Network Interface Card (NIC)
The electronic hardware used to interface the computer to the network
31
Network Layer (3rd layer)
Defines how data packets are routed in a network. Accepts outgoing messages and combines messages
or segments into packets, adding a header that includes routing information (provides a logical path for data)
32
Network Number
The portion of the IP address that defines which network the IP packet is originating from or being
delivered to
33
Organizationally Unique Identifier (OUI)
The first 3 bytes of the MAC address that identifies the manufacturer of the network hardware (ex. Network
interface card has MAC address of 00-00-86-15-7A, the OUI is 00-00-86).
34
OSI
Open system interconnect
35
OSI Model
The seven layers describing network functions
36
Overloading
Where NAT translates the home network's private IP addresses to a single public IP address
37
Packet
Provides grouping of the information for transmission
38
Ping
Command used to test that a device on the network is reachable (If you can't connect to a networked
computer, you can use the ping command to check connectivity) Used in windows in the command window
39
Port Address Translation (PAT)
A port number is tracked with the client computer's private address when translating to a public address
40
Ports
The physical input/output interfaces to the networking hardware
41
Presentation Layer (6th layer)
Layer of the OSI reference model that accepts and structures the messages for the application
42
Private Addresses
IP addresses set aside for use in private intranets
43
Protocol
Set of rules established for users to exchange information
44
Range Extender
Device that relays the wireless signals from an access point or wireless router into areas with a weak signal
or no signal at all
45
RJ-45
The 8-pin modular connector used with CAT6/5e/5 cable
46
Service Set Identifier (SSID)
Name that is used to identify your wireless network and is used by your access point or wireless router to
establish and association
47
Session Layer (5th layer)
Layer of the OSI reference model that provides the control functions necessary to establish, manage, and terminate the connections (SQL and NFS technologies
are on the session layer)
48
SSID
Service set identifier
49
Star Topology
The most common networking topology in today's LANs where all networking devices connect to a central
switch or hub, each device connects to a central point via a point-to-point link. Each device is connected to its own port
50
Stateful Packet Inspection (SPI)
Type of a firewall that inspects
51
6to4 Prefix
a technique that enables IPv6 hosts to communicate over the IPv4 Internet
52
Access Control Lists (ACLs)
A basic form of firewall protection
53
ACK
Acknowledgement packet
54
AES
Advanced Encryption Standard
55
AH
Authentication Header
56
Anycast Address
Is obtained from a list of addresses
57
ARIN
American Registry for Internet Numbers
58
ARP
Address Resolution Protocol, used to map and IP address to its MAC address (the destination gets the
sender's addresses from the ARP request)
59
ARPAnet
Advanced Research Projects Agency network
60
Brute Force Attack
Attacker uses every possible combination of characters for the password
61
Buffer Overflow
Happens when a program tries to put more data into a buffer than it was configured to hold
62
CHAP
Challenge Handshake Authentication Protocol
63
CIDR
Classless interdomain routing
64
CIDR Block
The grouping of two or more class networks together; also called supernetting
65
Class A, B, C, D, and E
The five classes of IPv4
66
Classful
The IP and subnet addresses are within the same network
67
Connection-Oriented Protocol
Establishes a network connection, manages the delivery of data, and terminates the connection
68
Denial of Service (DoS)
A service is being denied to a computer, network or server
69
DES, 3DES
Data Encryption Standard, Triple Data Encryption Standard
70
Dictionary Attack
Uses known passwords and many variations (upper- and lowercase and combinations) to try to log in to
your account
71
Diffie-Hellman
Key generation algorithm
72
Directed Braoadcast
The broadcast is sent to a specific subnet
73
EAP
Extensible Authentication Protocol
74
ESP
Encapsulating Security Protocol
75
Firewall
Used in computer networks for protecting the network; Personal firewall software is typically based on basic packet filtering inspections where the firewall accepts or denies incoming network traffic based on information contained int he packet's TCP or IP headers.
76
Full IPv6 Address
All 32 hexadecimal positions contain a value other than 0 (double colons, 32 hex characters, 128 bits)
77
GRE
Generic Routing Encapsulation
78
Hex
Hexadecimal, base 16
79
ICANN
The Internet Corporation of Assigned Names and Numbers
80
IGMP
Internet Group Message Protocol (Used for streaming media... data is passed through to the application layer
for immediate processing without error checking
81
IKE
Internet Key Exchange
82
Internet Layer
Defines the protocols used for addressing and routing data packets
83
IP (Internet Protocol)
Defines the addressing used to identify the source and destination addresses of data packets being delivered
over an IP network
84
IP Tunnel
An IP packet encapsulated in another IP packet (a secure VPN connection between two endpoints in
known as an IP Tunnel)
85
IPng
The next generation IP
86
IPsec
IP security is used to encrypt data between various networking devices (AES, ESP, and DES are security
protocols, not TKIP which is wireless protocol).
87
IPv4
The IP version currently being used on the Internet (Dotted decimal) Uses five classes of IP addresses, is
being replaced by IPv6. Made of up 4 bytes and octets. An octet is 8 bits. 4 make up 32 bits of an IP address.
88
IPv6
IP version 6 (unicast, multicast, and anycast all IPv6 addresses)
89
ISAKMP
Internet Security Association and Key Management Protocol
90
L2F
Layer 2 Forwarding
91
L2TP
Layer 2 Tunneling Protocol
92
Malware
Malicious programs
93
MD5
Message Digest 5
94
Multicast Address
Data packets sent to a multicast address are sent to the entire group of networking devices, such as a
group of routers running the same routing protocol
95
Multicasting
When one host sends data to many destination hosts
96
NCP
Network Control Protocol
97
netstat -a -b
(a) Command used to display the ports currently open on a Windows operating system and (b) used to display
the executable involved in creating the connection or listening port
98
Network Interface Layer
Defines how the host connects to the network
99
Non-Internet Routable IP Addresses
IP addresses not routed on the Internet
100
Packet Filtering
A limit is placed on the information that can enter the network
101
Packet Sniffing
A technique in which the contents of data packets are watched (assumes that the attacker can see the
network data packets; performed using a machine attached to the network)
102
PAP
Password Authentication Protocol
103
PPP
Point-to-Point Protocol (the de facto standard in dial- up VPNs)
104
PPTP
Point to Point Tunneling Protocol
105
Prefix length notation
Another shorthand technique for writing the subnet mask except class boundaries are not being crossed
106
Proxy Server
Clients go through a proxy to communicate with secure systems
107
RIRs
Regional Internet registries, IANA-designated governing organizations responsible for IP address
allocation by geographical location
108
SHA-1
Secure Hash Algorithm
109
Social Engineering
A way for an intruder to obtain enough information from people to gain access to the network
110
Spoof
Inserting a different IP address in place of an IP packet's source address to make it appear that the
packet came from another network
111
Stateful Friewall
Keeps track of the data packet flow
112
Supernets
The grouping go two or more class networks together; also called CIDR blocks
113
Supernetting
Allows multiple networks to be specified by one subnet mask (allows the representation of multiple networks
with one address)
114
SYN
Synchronizing packet
115
SYN ACK
Synchronizing Acknowledgement packet
116
TCP
Transport Control Protocol (example of a connection- oriented protocol)
117
Transport Layer Protocols
Define the type of connection established between hosts and how acknowledgements are sent
118
UDP
User Datagram Protocol; UDP is a connectionless protocol that doesn't use acknowledgements
119
Unicast Address
Used to identify a single network interface address, and data packets are sent directly to the computer with
the specified IPv6 address
120
Virus
A piece of malicious computer code that, when opened, can damage your hardware, software, or other
files
121
Well-known Ports
Ports reserved by ICANN
122
Worm
A type of virus that attacks computers, typically proliferates by itself, and can deny service to networks
123
10GBASE-T
10Gbps over twisted-pair copper cable (splits the data into 4 channels of 2.5G each) Uses multilevel encoding
to reduce required bandwidth for transmission
124
ACR
The attention-to-crosstalk ratio measurement compares the signal level from a transmitter at the far
end to the crosstalk measured at the near end. A larger ACR indicates that the cable has a greater data capacity and also indicates the cable's ability to handle a greater bandwidth. Essentially, it is a combined measurement of the quality of the cable. A higher ACR value (dB) is desirable.
125
Alien Crosstalk (AXT)
Unwanted signal coupling from one permanent link to another
126
Attenuation (Insertion Loss)
The amount of loss in the signal strength as it propagates down a wire or fiber strand (leakage and
resistance cause attenuation in fiber optic systems).
127
Balanced mode
Neither wire in the wire pairs connects to ground
128
Bottlenecking
Another term for network congestion
129
Building Entrance
The point where the external cabling and wireless services interconnect with the internal building cabling
130
Campus Network
A collection of two or more interconnected LANs in a limited geographic area
131
CAT7/7a and CAT6a
UTP cable standards that support 10GB data rates for a length of 100 meters
132
Color Map
The specification of which wire color connects to which pin on the connector
133
Cross-connect
A space where you are going to take one or multiple cables and connect them to one or more cables or
equipment
134
Crossover Cable
Transmit and receiver wire pairs are crossed (transmit and receive wires crossed, don't connect to the same
pins on each end)
135
Crosstalk
Signal coupling in a cable
136
Delay Skew
This is a measure of the difference in arrival time between the fastest and the slowest signal in a UTP
wire pair
137
EIA
Electronic Industries Alliance
138
EIA/TIA 568-B
The standard that defines the six subsystems of a structured cabling system
139
ELTCTL
Equal Level Transverse Conversion Transfer Loss
140
EMI
Electromagnetic Interference
141
Entrance Facilities (EF)
A room set aside for complex electronic equipement
142
Equal Level FEXT (ELFEXT)
This measurement differs from NEXT in that the measurement is for the far end of the cable. Additionally, the LFEXT measurement does not depend on the length of the cable. This is because ELFEXT is obtained by subtracting the attenuation value from the far-end crosstalk (FEXT!!) loss
143
Equipment Room (ER)/Backbone Cabling
Cabling that interconnects telecommunication closets in the same building and between buildings
144
F/UTP
Foil over twisted-pair cabling (better security, noise immunity for EMI) It minimizes signal leakage and
provides noise immunity from EMI
145
FastEthernet
An Ethernet system operating at 100MBps
146
Full Channel
Consists of all the link elements from the wall plate to the hub or switch
147
Full Duplex
Computer system can transmit and receive at the same time (full duplex gigabit Ethernet uses 4 pairs)
148
Gigabit Ethernet / twisted pair cables
1000Mbps Ethernet; CAT6 and CAT5e rated for 1000Mbps
149
Horizontal Cabling
Cabling that extends out from the telecommunications closet into the LAN work area
150
Horizontal Cross-connect (HC)
The connection between the building distributors and the horizontal cabling to the work area or workstation
outlet-another term used for the HC is the floor distributors (FD)
151
Hybrid Echo Cancellation Circuit
Removes the transmitted signal from the receive signal
152
IEEE 802.3an-2006 10GBASE-T
The standard for 10 Gbps
153
Intermediate Cross-connect (IC)
Also called the building distributor (BD), this is the building's connection point to the campus backbone.
The IC links the MC to the horizontal cross-connect (HC).
154
LCL
Longitudinal Conversion Loss
155
Link
Point from one cable termination to another
156
Main Cross-connect (MC)
Usually connects two or more buildings and is typically the central telecommunications connects point for a campus or building. It is also called the main distribution frame (MDF) or main equipment room. The MC connects to Telco, and ISP, and so on. Another term for the MC is the campus distributor (CD).
157
Multilevel Encoding
Technique used to reduce in the required bandwidth required to transport the data
158
Near-end Crosstalk (NEXT)
A measure of the level of crosstalk or signal coupling within the cable, with a high NEXT (dB) value being
desirable.
159
Network Congestion
A slowdown on network data traffic movement
160
Nominal Velocity of Propagation (NVP)
NVP is some percentage of the velocity of light and is dependent on the type of cable being tested. The typical delay value for CATD/De UTP cable is about 5.7 nsec per meter. The EIA/TIA specification allows for 548 nsec for the maximum 100-meter run for CAT5e, CAT6, CAT6, CAT6a, CAT7, and CAT7A
161
Power Sum NEXT (PSNEXT)
The enhanced twisted-pair cable must meet four-pair NEXT requirements, called PSNEXT testing. Basically, power sum testing measures the total crosstalk of all cable pairs. This test ensures that the cable can carry data traffic on all four pairs at the same time with minimal interference. A higher PSNEXT value is desirable because it indicates better cable performance.
162
Propagation Delay
This is a measure of the amount of time it takes for a signal to propagate from one end of the cable to the
other. The delay of the signal is affected by the nominal velocity of propagation (NVP) of the cable.
163
PSAACRF
Power-Sum Alien Attenuation Cross-talk Ratio Far-End
164
PSACR
Power Sum ACR uses all four wire pairs to obtain the measure of the attenuation-crosstalk ratio. This is a measurement of the difference between PSNEXT and attenuation (insertion loss). The difference is measure in dB, and higher PSACR dB values indicate better cable performance.
165
PSANEXT
Power-Sum Alien Near-End Crosstalk
166
PSELFEXT
Power sum ELFEXT that uses all four wire pairs to obtain a combined ELFEXT performance measurement. This value is the difference between the test signal level and the cross-talk measured at the far end of the cable. A higher PSELFEXT value indicated better cable performance.
167
Return Loss
This measurement provides a measure of the ratio of power transmitted into a cable to the amount of power
returned or reflected.
168
RX
Abbreviation for receive
169
STP
Shielded twisted pair; not good for noisy environments... blocks EMI, has metal foil placed
around the wires
170
Straight-through
Transmit and receive signal pairs are aligned end-to- end
171
Straight-through Cable
The wire pairs int he cable connect to the same pin numbers on each end.
172
TIA/EIA 568A
Wire color guidelines specified under the EIA/TIA568B standard (developed in 1995)
173
T568B
Wire color guidelines specified under the EIA/TIA568B standard
174
TCL
Transverse Conversion Loss
175
TCO
Telecommunications outlet
176
TCTL
Transverse Conversion Transfer Loss
177
Telecommunications Closet
```
The location of the cabling termination points that includes the mechanical termination and the
distribution frames (networking equipment, patch cables, backbone cabling, patch panels)
```
178
TIA
Telecommunications Industry Association
179
TR
Another name for the telecommunications closet
180
TX
Abbreviation for transmit
181
Wire-map
A graphical or text description of the wire connections from pin to pin
182
Work Area
The location of the computers and printers, patch cables, jacks, computer adapter cables, and fiber
jumpers
183
Workstation or Work Area Outlet (WO)
Also called the TO (telecommunications outlet), it's used to connect devices to the cable plant. The cable type typically used is CAT3, CAT5, CAT5e, CAT6, CAT6A, and various coaxial cables. Devices typically connected to these outlets are PCs, printers, servers, phones, television, and wireless access points.
184
Switch
Forwards a frame it receives directly out the port associated with its destination address (get the MAC
addresses form the data packets) Minimize unneeded data traffic, isolate portions of the network
185
TCP/IP
Transmission Control Protocol/Internet Protocol, the protocol suite used for internetworks such as the
Internet
186
ThinNet
A type of coaxial cable used to connect LANs configured with a bus topology
187
Token Passing
A technique where an electrical token circulates around a network-control of the token enables the
user to gain access to the network
188
Token Ring Hub
A hub that manages the passing of the token in a Token Ring network
189
Token Ring Topology / Network
A network topology configured in a logical ring that complements the token passing protocol (one failed station causes network shutdown, difficult to reconfigure, diffident to troubleshoot; each system must relay the token, if there is any failure the entire system goes down. It can be hard to determine which one it is.
190
Topology
Architecture of a network
191
Transport Layer (4th layer)
Layer of the OSI reference model that is concerned with message integrity between source and destination
192
Uplink Port
Allows the connection of a hub or switch to another hub or switch without having to use a crossover cable
(an X label is on the uplink ports)
193
Virtual Private Network (VPN)
Establishes a secure network connection and is a way to protect your LAN's data from being observed by
outsiders
194
Wired Network
Uses cables and connectors to establish the network connection
195
Wireless Network
Uses radio signal to establish the network connection... wireless signal can be incepted easier than wire
signals
196
Wireless Router
Device used to interconnect wireless networking devices and to give access to wired devices and
establish the broadband Internet connection to the ISP
197
Absorption
Light interaction with the atomic structure of the fiber material; also involves the conversion of optical power
to heat
198
Chromatic Dispersion
The broadening of a pulse due to different propagation velocities of the spectral components of the light pulse
(affects both single mode and multimode fibers)
199
Cladding
Material surrounding the core, which must have a lower index of refraction to keep the light in the core
200
Dense Wavelength Division Multiplex (DWDM)
Incorporates the propagation of several wavelengths in the 1550-nm range for a single fiber
201
Dispersion
Broadening of a light pulse as it propagates through a fiber strand (light isn't a cause of dispersion, it is
affected by dispersion)
202
Dispersion Compensating Fiber
Acts like and equalizer, canceling dispersion effects and yielding close to zero dispersion int he 1550-nm region (developed to increase the transmission capacity of older cabling; allows the use of 1550nm transmission on lines that were designed for 1310nm region)
203
Distributed Feedback (DFB) Laser
A more stable laser suitable for use in DWDM systems
204
DL
Diode laser
205
Fiber Bragg Grating
A short strand of modified fiber that changes the index of refraction and minimized intersymbol
interference
206
Fiber Cross-connect
Optical patch panel used to interconnect fiber cables
207
Fiber, Light Pipe, Glass
Terms used to describe a fiber-optic strand
208
FTTB
Fiber to the business
209
FTTC
Fiber to the curb
210
FTTD
Fiber to the desktop
211
FTTH
Fiber to the home
212
Fusion Splicing
A long-term method where two fibers are fused or welded together into one piece of glass
213
GBIC
Gigabit interface converter (optical-to-fiber interfaced used at 1 gigabit)
214
Graded-index Fiber
The index of refraction is gradually varied with a parabolic profile (overcomes modal dispersion)
215
IC
Interconnect fibers branch exchange-item D shows the jumpers connecting the main fiber cross-connect (item
B) to the active equipment (item C)
216
IDC
Intermediate distribution closet
217
Index-matching Gel
A jellylike substance that has an index of refraction much closer to glass that to air
218
Infrared Light
Light extending from 680 nm up to the wavelengths of the microwaves
219
Isolator
An inline passive device that allows optical power to flow only in one direction
220
LED
Light-emitting diode
221
Logical Fiber Map
Shows how the fiber is interconnected and data is distributed throughout a campus (data distribution,
fiber interconnections)
222
Long Haul
The transmission of data over hundreds or thousands of miles
223
Macrobending
Loss due to light breaking up and escaping into the
| cladding
224
Mechanical Splices
Two fibers joined together with an air gap, thereby requiring an index-matching gel to provide a good
splice
225
Microbending
Loss caused by very small mechanical deflections and stress on the fiber
226
mm
Multimode
227
Modal Dispersion
The broadening of a pulse due to different path lengths taken through the fiber by different modes
228
Mode Field Diameter
The acutal guided optical power distribution, which is typically a micron or so larger thent he core diameter;
single-mode fiber specifications typically list the mode field diameter
229
Multimode Fiber
A fiber that supports many optical waveguide modes; use light in the 850 nm and 1310 nm range
230
Numerical Aperture
A measure of a fiber's ability to accept light
231
Optical Ethernet
Ethernet data running over a fiber link
232
Optical Spectrum
Light frequencies from the infrared on up
233
Physical Fiber Map
Shows the routing of the fiber but also shows detail about the terrain, underground conduit, and entries
into buildings
234
Polarization Mode Dispersion
The broadening of a pulse due to the different propagation velocities of the X and polarization
components of the light pulse
235
Pulse Dispersion
Stretching of received pulse width because of multiple paths taken by the light
236
Received Signal Level (RSL)
The input signal level to an optical receiver
237
Refractive Index
Ratio of the speed of light in free space to its speed in a given material
238
SC, ST, FC, LC, MT-RJ
Typical fiber connectors on the market (need to be easy to install and economical)
239
Scattering
Caused by refractive index fluctuations; accounts for 96 percent of attenuation loss
240
Single-mode Fiber
Fiber cables with core diameters of about 7-10 um; light follows a single path (use light in the 1310 nm
and 1550 nm range) Uses high-power, highly directional modulated light sources; single-mode fibers are used with lasers.
241
sm
Single mode
242
SONET/SDH
Synchronous optical network; protocol standard for optical transmission in long-haul
communication/synchronous digital hierarchy
243
STS
Synchronous transport signals
244
Tunable Laser
Laser in which the fundamental wavelength can be shifted a few nanometers, ideal for traffic routing in
DWDM systems
245
Vertical Cavity Surface Emitting Lasers (VCSELs)
Lasers with the simplicity of LEDs and the performance of lasers
246
XENPAK, XPAK, X2, XFP, SFP+
The ten gigabit interface adapter
247
Zero-dispersion Wavelength
Point where the dispersion is actually zero
248
Aging Time
The length of time a MAC address remains assigned to a port; length of time an IP address is assigned to a
switchport
249
ARP Cache
Temporary storage of MAC addresses recently contacted
250
ARP Table
Another name for the ARP cache
251
Association
```
Indicates that the destination address is for a networking device connected to one of the ports on
the bridge (describes a wireless connection and MAC address: wireless connection has been obtained, provides the client MAC address)
```
252
AUI Port
This is a 10Mbps Ethernet port. AUI stands for "attachment unit interface."
253
Auto-negotiation
Protocol used by interconnected electronic devices to negotiate a link speed (failed negotiation can cause a
link failure, not recommended for fixed data links) The link can only go as fast as the slowest link.
254
Auxiliary Input
Used to connect a dial-in modem into the router. The auxiliary port provides an alternative way to remotely
log in to the router if the network is down. This port also uses an RJ-45 connection
255
Bridge
A networking device that uses the MAC address to forward data and interconnect two LANs (easy to install) Only forwards data to the specified port, isolates the network traffic, uses MAC addresses to forward data packets. The association tells the bridge where to forward a data packet.
256
Bridging Table
List of MAC addresses and port locations for hosts connected to the bridge ports
257
Broadcast
Transmission of data by a network device to all devices connected to its ports
258
Broadcast Domain
Any network broadcast sent over the network will be seen by all networking devices in this domain
259
Broadcast Storm
Excessive amounts of broadcasts; can cause network slowdowns
260
Cisco Network Assistant (CNA)
A management software tool from Cisco that simplifies switch configuration and troubleshooting
261
Console Input
Provides a RS-232 serial communications link into the router for initial router configuration. A special cable, called a console cable, is used to connect the console input to the serial port on a computer. The console cable uses RJ-45 plugs on each end and requires the use of an RJ-45 to DB9 adapter for connecting to the COM1 or COM2 serial port
262
Content Addressable Memory (CAM)
A table of MAC addresses and port mapping used by the switch to identify connected networking devices
263
Cut-Through switching
The data packet is forwarded to the destination as soon as the destination MAC address has been read; cut through switching doesn't read the entire frame,
just the MAC address. Low latency
264
Dynamic Assignment / Addressing
MAC addresses are assigned to a port when a host is connected (addresses are assigned dynamically when
using dynamic addressing)
265
Enterprise Network
Term used to describe the network used by a large company
266
Error Threshold
The point where the number of error in the data packets has reached a threshold and the switch
changes from the cut-through to the store-and- forward mode
267
Fast Link Pulse (FLP)
Carries the configuration information between each end of a data link (designed to operate over limited
bandwidth)
268
FastEthernet Port (FA0/0, FA0/1, FA0/2,...)
Naming of the FastEthernet ports on the router
269
Flooding
The term used to describe what happens when a switch doesn't have the destination MAC address
stored in CAM
270
Gateway
Describes the networking device that enables hosts in a LAN to connect to networks (and hosts) outside the
LAN
271
Half-Duplex
The communications device can transmit or receive but not at the same time
272
Isolating the Collision Domains
Breaking the network into segments where a segment is a portion of the network where the data traffic from
one part of the network is isolated from the other networking devices
273
Layer 2 Switch
An improved network technology that provides a direct data connection for network devices in a LAN
274
Logical Address
Describes the IP address location of the network and the address location of the host in the network
275
Managed Switch
Allows the network administrator to monitor, configure, and manage select network features
(managed switches can be managed remotely)
276
Media Converter
Used to adapt a layer 1 (physical layer) technology to another layer 1 technology
277
Multicast
Messages are sent to a specific group of hosts on the network
278
Multilayer Switch (MLS)
Operates at layer 2 but functions at the higher layers
279
Multiport Bridge
Another name for a layer 2 switch
280
Network Address
Another name for the layer 3 address (routers use the network address to route packets)
281
Network Slowdown
Degraded network performance
282
Power On/Off
Turns on/off electrical power to the router
283
Router Interface
The physical connection where the router connects to the network; serial, ethernet, and auxiliary can all be
used to connect to the network.
284
Routing Table
Keeps track of the routes to use for forwarding data to its destination
285
Secure Address
The switch port will automatically disable itself if a device with a different MAC address connects to the
port
286
Serial Port (S0/0, S0/1, So/2,...)
Naming of the serial ports on the router
287
Serial Ports
Provides a serial data communication link into and out of the router, using V.35 serial interface cables
288
Store-and-Forward
The entire frame of data is received before any decision is made regarding forwarding the data packet
to its destination
289
Switch Latency
The length of time a data packet takes from the time it enters a switch until it exists
290
Translation Bridge
Used to interconnect two LANs that are operating two different networking protocols
291
Transparent Bridge
Interconnects two LANs running the same type of protocol
292
Wire Speed Routing
Data packets are processed as quickly as they arrive
293
Access Point
A transceiver used to interconnect a wireless and a wired LAN (looks at the SSID to determine if the data
packet is intended for its network)
294
Ad Hoc
Another term used to describe an independent network
295
Backscatter
Refers to the reflection of the radio waves striking the RFID tag and reflecting back to the transmitter source
296
Basic Service Set (BSS)
Term used to describe an independent network
297
Beacon
Used to verify the integrity of a wireless link
298
BWA
Broadband wireless access
299
CSMA/CA
Carrier sense multiple access/collision avoidance
300
DSSS
Direct sequence spread spectrum
301
Extended Service Set (ESS)
The use of multiple access points to extend user mobility (allows a wider range of wireless signals using
roaming)
302
FHSS
Frequency hopping spread spectrum
303
Hand-off
When the user's computer establishes an association with another access point
304
Hopping Sequence
The order of frequency changes
305
Inquiry Procedure
Used by Bluetooth to discover other Bluetooth devices or to allow itself to be discovered
306
ISM
Industrial, scientific, and medical
307
Last Mile
The last part of the connection from the telecommunications provider to the customer
308
MIMO
A space-division multiplexing technique where the data stream is split into multiple parts called spatial
streams (uses space-division multiplexing to transmit different data streams in parallel)
309
NLOS
Non-line-of-sight
310
OFDM
Orthogonal frequency division multiplexing
311
Paging Procedure
Used to establish and synchronize a connection between two Bluetooth devices
312
Pairing
When a Bluetooth device is set up to connect to another Bluetooth device
313
Passkey
Used in Bluetooth Security to limit outsider access to the pairing
314
Piconet
An ad hoc network of up to eight Bluetooth devices
315
Pseudorandom
The number sequence appears random but actually repeats
316
Radio Frequency Identification (RFID)
A technique that uses radio waves to track and identify people, animals, objects, and shipments (full speed
tollbooths, tracking shipments, border crossings) Parameters that define an RFID system is frequency of operation, power, and protocol
317
RADIUS
Remote Authentication Dial-In User Service (prevents unauthorized users to connect to the network as well as preventing users form connecting to rogue access
points)
318
Roaming
The term used to describe a user's ability to maintain network connectivity as he moves through the
workplace
319
Site Survey
Performed to determine the best location(s) for placing the access point(s) to provide maximum RF coverage
for the wireless clients (conducted both inside and outside)
320
Slotted Aloha
A wireless network communications protocol technique similar to the Ethernet protocol
321
Transceiver
A transmit/receive unit
322
U-NII
Unlicensed National Information Infrastructure
323
Wi-Fi
Wi-Fi Alliance(md) and organization that tests and certifies wireless equipment for compliance with the
802.11x standards
324
WiMAX
A broadband wireless system based on the IEEE 802.16e standard (30 miles max range)
325
WLAN
Wireless local area network
326
WPA
Wi-Fi Protected Access
327
The Transport Layer (4th layer)
The transport layer protocols in TCP/IP are very important in establishing a network connection, managing the delivery of data between a source and destination host, and terminating the data connection (TCP and UDP are the only protocols on the Transport layer).
328
HTTP Port Number
80
329
Bluetooth
Operates in the 2.4 GHz band; 802.11n, 802.11b, 802.11g (802.11a operates in the 5Gz range)
330
Core size of multimode cables
62.5
331
Patch Cable
Used to make the physical connection to the wall plate
332
Stretching of a received pulse is due to
Pulse-dispersion and Multiple paths taken by the light waves
333
EIA/TIA568-B.2 and 568-2.1
specify the cabling components and transmission of copper cabling hardware
334
10.10.20.250
Example of a private IP address, a nonroutable Internet IP address, Class A address
335
Antivirus software
Signatures or definitions contain traits of the specific virus or worm
336
MAC address filtering
Only devices with specified layer 2 addresses will be allowed to access the network... lets you specify which
devices can connect to the network
337
10101010
Provide MAC functions to allow users to connect to each other; provides 802.11 MAC layer functions
338
Cisco LEAP
User must provide the correct password
339
Router Routing tables
Keep track of the addresses needed to route data. Contains addresses of adjacent routers and the
networks that they can reach. It also includes the metric and method of learning the route. Use the ip route command to the the routing table.
340
Maximum length for multimode fiber optic cable
2000 meters or 2 km
341
Wired networks
Can have data rates as high as 100Gbps
342
no ip directed-broadcast network command
Prevents networks from becoming intermediate sites for network attacks. On a Cisco router prevents a
network form becoming an intermediate site for a network attack
343
Hexadecimal equivalent of 1011
B = 1011 = 11
344
Serial Interface
Used to create a T1 connection; sometimes has a built-in CSU/DSU
345
802.11 technologies
Don't use visible light; use FHSS, DSSS, infrared
346
Secure a wireless home network
Turn on encryption; turning on WEP, WPA or WPA-2 will encrypt the data
347
Class C usable IP network addresses
192.0.0.0 - 223.255.255.255 (there are 24 network bits; the first three octets are used with 24 bits total)
348
150.25.191.255
broadcast address for 150.25.151.68 with a mask of 255.255.192.0
349
How many wire pairs are used for gigabit Ethernet
4: all 4 wire pairs are used for transmission at 1 Gbps speeds
350
Wireless security guidelines
Use firewalls, turn on access point security features. Technology in any frequency band may be used and
3rd party tools must be used end-to-end.
351
Network Segment
A segment is associated with each networking device; the networking link between 2 LANs
352
Intrusion detection
the monitoring of data packets passing through the network to catch potential attacks; the monitoring of
data packets passing through the network to catch ongoing attacks. The first issue of intrusion is Social Engineering.
353
Private IP address
Cannot be used on the Internet, only Intranets
354
OC-3 bit rate
155.52 Mbps
355
UTP wire pair length difference
can be due to poor manufacturing, can be due to inconsistent twists, cause the cable not to be certified... cable testing will reveal these issues. The inconsistent length can cause failure if one wire is over 100 meters while the others are not. Due to the difference in the cable twists for each wire pair.
356
255.255.255.224
Expressed as a /27 using CIDR notation because there are 27 1s in the subnet mask
357
192.168.55.0 dived into multiple subnets, need at lest 30 host ID's in each subnet; maximum number of subnets you could have?
8: Class C address and we must use 5 bits for our hosts (2 to the 5th -2 = 30 hosts). That leaves 3 bits to use for subnets. 2 to the 3rd = 8 subnets.
358
Probing
Indicators of repeated attempts to make connections to certain machines
359
Core
Carries the light signals in a fiber optic cable
360
Static assignment
MAC address that has been manually assigned
361
SMTP Port Number
25
362
Router
Interconnect LANs; routers know where to send packets coming into or leaving the LAN; router ports
commonly refereed to as interfaces which provide the physical connection to the network
363
Ethernet (DIX) frame after the Preamble
Destination address, Source address, Type/Length, Data, Pad, FCS
364
Fiber optic communication system
Source, cable, connectors, photodiode... the link may have splices but it must have connectors
365
255.255.252.0
Expressed as /22 using CIDR notation becasue there are 22 1s in the subnet mask
366
Well-known ports
ICANN reserves these ports for particular protocols
367
SYN Flood
Attackers send SYN packets to set up virtual connections that use up the connection buffer...
denial-of-service attack characterized by using all connections available on a computer
368
How many usable host IP addresses are provided: network IP address of 192.168.12.0 and a subnet
mask of 255.255.255.252
2
369
Telnet Port
23
370
DSL Modem
Used to connect to a broadband network through your telephone connection only. Broadband modems can
connect using cable or telephone technology.
371
Physical Architecture of a computer network
Topologies, A physical topology is the actual layout of the network.
372
SLA ID
Used to identify subnets in an IPv6 address
373
802.11u
802.11x standard increases security by incorporating user authentication, not 802.11u
374
Correct order sequence of packets that are sent to set up a virtual TCP connection
The three-way handshake is used to create virtual TCP connections: SYN, SYN-ACK, ACK
375
802.11g advantage
Compatible with 802.11b, high speed
376
What tools are needed to make a UTP cable?
Crimping Tool and strippers are used to terminate UTP cables
377
FTP Port Number
21
378
Layered Protocol Specifications
Multi vendor interoperability, easier to develop, easier to learn; Multivendor engineering not a benefit because doesn't specify how it should work, just what it needs to be able to do.
379
Designing a LAN
1. document all devices 2. develop and addressing scheme, physically connect devices and configure
devices to communicate
380
With an address of 197.15.22.31 and a subnet mask of 255.255.255.224 how many bits have been borrowed to create a subnet?
3. 224 = 11100000, 3 bits on
381
Light detector characteristics
Responsitivity, response speed, spectral response
382
Decimal equivalent of 11110000
11110000 = 240
