CNT120 CHAP 6
WPA
encryption that dynamically assigns every transmission its own key
WEP
encryption that uses a static key to authenticate and encrypt the clients data - use of the shared key makes it more susceptible to discovery - has been replaced by WPA/WPA2
management frame
frame involved in association and reassociation - such as probe and beacon
data frames
frames involved in carrying the data between stations
active scanning
the station transmits a special frame, known as a probe, on all available channels within its frequency range
CSMA/CD
IEEE 802.3 Wired Ethernet Networks
True
Most WLANs utilize frequencies around 2.4 GHz or 5 GHz to send and receive wireless signals.
WLANs
Networks that transmit signals through the air via radio frequency (RF) waves are known as ____________.
BSS
a group of nodes that share an access point
Frame Aggregation
-Combine multiple frames into one larger frame -Reduces Overhead
attenuation
After a signal is transmitted, the farther it moves away from the transmission source, the more it weakens. Similar to wired transmission, wireless signals can be amplified by increasing the power of the transmission or extended by repeating the signal from a closer broadcast point called a wireless range extender.
True
Collectively the IEEE 802.11 standards and their amendments, extensions, and corrections are known as Wi-Fi, which stands for Wireless Fidelity.
DSSS
Data streams are divided and encoded into small chunks, which are spread over all available frequencies within one of three, wide channels, all at the same time.
CSMA/CA
IEEE 802.11 Wireless Ethernet Networks
3
Wired and Wireless signals share many similarities, including the use of the same Layer _____ and above protocols.
RFID
________ uses electromagnetic fields to store data on a small chip in an ________ tag, which includes an antenna that can both transmit and receive, and possibly a battery. The tag holds 1 to 8 KB of data, such as serial number, credit card info, or medical data, which can transmit to a nearby reader.
spectrum analyzer
a device that can assess the quality of the wireless signal - helps with identifying where interference is greatest
heat map
a map of Wi-Fi signals and noise in your location
captive portal
the first page a new wireless client sees in the browser when connecting to a guest network
passive scanning
the station listens on all channels within its frequency range for a special signal, known as a beacon frame, issued from an access point
SSID
The ______ is a unique character string used to identify an access point.
more overhead
The use of ACK packets to verify every transmission means that 802.11 networks require __________________ than 802.3 networks.
1 and 2
WLANs work at OSI Layers ______. They support the same TCP/IP higher-layer OSI protocols and operating systems (Windows, Unix, Linux, Apple) as wired LANs.
diffraction
When a wireless signal is split into secondary waves when it encounters an obstruction. The waves appear to "bend around an obstacle". This is caused by objects with sharp edges including corners of walls or desks.
reflection
When waves encounter an obstacle and the signals "bounce off". This is usually caused by large flat surfaces - walls, ceilings, floors, etc...
off-boarding
Removing the app or agent that gave devices special permissions on the network
MIMO
-Multiple antennas on access points and client devices process incoming and outgoing data simultaneously -Increases network's throughput, access point's range -First Available in 802.11n Access Points
Channel Bonding
-Two adjacent 20-MHz channels bonded to make 40-MHz channel -Doubles the bandwidth available in single 20-MHz channel
MU-MIMO
-that allows multiple antennas to service multiple clients simultaneously -Reduces congestion and contributes to faster data transmission -Available with WAVE 2 802.11ac products
War Driving
A hacker searches for unprotected wireless networks by driving around with a laptop configured to receive and capture wireless data transmissions
WPAN
A mini version of a LAN is a PAN, and the purely wireless version is a ________, as defined by the IEEE 802.15 specifications.
Evil Twin
A rogue AP planted in a network's geological area to pose as an authorized AP
FHSS
Short bursts of data are transmitted on a particular frequency within the band and the next burst goes to the next frequency in the sequence.
less
A wireless network with a theoretical maximum throughput of 10 Mbps will, in fact, transmit _________ data per second than a wired Ethernet network with the same theoretical maximum throughput of 10 Mbps.
IoT
All sorts of things can be connected to a network, from toasters, refrigerators, bathrooms scales, and garage doors to watches, lamps, cars and even the kitchen sink. This _____ is made up of any device that can be connected to the Internet - that is any sensor, computer or wearable device that talks to other devices over a network.
wireless spectrum
All wireless signals are carried through the air by electromagnetic waves. The ______________, commonly called the airwaves, is the frequency range of electromagnetic waves used for data and voice communications.
radiation pattern
An antenna's ___________________ describes the relative strength over a three-dimensional area of all the electromagnetic energy the antenna sends or receives.
rogue access point
An unauthorized wireless access point is called a(n) _____________.
fading
As a signal runs into various obstacles, its energy will gradually fade, which causes the strength of the signal that reaches the receiver to be lower than the transmitted signal's strength.
refraction
As waves travel into and through a different transmission medium, such as traveling through glass or other solids, the wave's direction, speed, and wavelength are altered, or "bent".
ESSID
BSSes that belong to the same ESS share a special identifier
ZigBee
Based on the IEEE 802.15.4 standard, _______ is a low-powered, battery-conserving wireless technology. It is designed to handle small amounts of data and is therefore ideal for use in ISM sensors. _____ is also used for IoT devices for purposes of building automation, HVAC control, AMR, and fleet management.
Wireless USB
Certified ______ products mimic wired USB 2.0 connections with similar speeds, security, ease of use and compatibility. _________ radios transmit in the range between 3.1 and 10.6 GHz.
interference
Electromagnetic waves in the atmosphere can interfere with wireless communications similar to how EMI affects wired transmissions.
802.11b
Freq Band - 2.4 GHz Max Throughput - 11 Mbps Effective Throughput - 5 Mbps Average Range - 100m
802.11g
Freq Band - 2.4 GHz Max Throughput - 54 Mbps Effective Throughput - 20-25 Mbps Average Range - 100m
802.11n
Freq Band - 2.4 GHz or 5 GHz Max Throughput - 600 Mbps Effective Throughput - 65-500 Mbps Average Range - Indoor 70m - Outdoor 250m
802.11ac
Freq Band - 5 GHz Max Throughput - 1.3 Gbps - 6.9 Gbps Effective Throughput - 561 Mbps per client Average Range - Indoor 70m - Outdoor 250m
802.11a
Freq Band - 5 GHz Max Throughput - 54 Mbps Effective Throughput - 11-18 Mbps Average Range - 50m
War Chalking
Hackers draw symbols with chalk on the sidewalk or wall near a vulnerable AP ... to make it known to other hackers
FCC
In the United States, the collection of frequencies available for communication - known as "the airwaves" - is considered a natural resource available for public use. The ____ grants organizations in different locations exclusive rights to use each frequency.
on-boarding
Installing a specific app or agent onto a device to give it trusted access to certain portions of the network
WPA Attacks
Involves an interception of the network keys communicated between stations and APs
site survey
Larger WLANs warrant a more systematic approach to access point placement. Before placing APs in every data room, it's wise to conduct a(n) __________. A(n) ___________ assesses client requirements, facility characteristics, and coverage areas to determine an AP arrangement that will ensure reliable wireless connectivity within a given area.
Address 1 & Address 4 fields
MAC address of sending node and MAC address of receiving node
ITU
The _____ is a United Nations agency that sets standards for international wireless services, including frequency allocation, signaling and protocols used by wireless devices; wireless transmission and reception equipment; satellite orbits and so on.
IEEE 802.11
The __________ data frame carries significant overhead - that is, it includes a large quantity of fields in addition to the data field.
9 kHz and 300 GHz
The wireless spectrum (as defined by the FCC) spans frequencies between _____ and _______.
RTS, CTS
WLANs can use the optional RTS/CTS protocol. The source node sends a ________ signal to the access point requesting the exclusive opportunity to transmit. If the access point agrees to the request it will respond with a ______ and will temporarily suspend communication through the access point and wait for the source node to complete transmission.
scattering
When a wireless signal encounters an object that has small dimensions compared with the signal's wavelength, it's diffused or "broken into pieces" into multiple directions. This is usually caused by rough surfaces. Indoors this can be caused by books, chairs, computers. Outdoors this can be caused by rain, mist, hail, and snow.
NFC
_____ is a form of RFID and transfers data wirelessly over very short distances (usually 10cm or less). A tiny antenna embedded in the device sends its radio signal at a fixed frequency of 13.56 MHz. The signal can also be transmitted one way by an _____ tag, or smart tag, such as when employees need to access a secure area of a building.
IR - Infrared
______ technology has found a new life in the world of IoT. ____ sensors are used to collect information such as: -presence or level of liquid -variations in reflections from skin caused by variations in blood flow which can be used to monitor heart rate -proximity to the device, which can trigger an action like steering a vehicle away from an object -commands from a control device
Z-Wave
_______ is a smart home protocol that provides 2 basic types of functions: signaling to manage wireless connections, and control, to transmit data and commands between devices. A ________ network controller, called a hub, receives commands from a smartphone or computer and relays the commands to various smart devices on its network.
Bluetooth
_______, defined by the IEEE 802.15.1 specifications, is named after a medieval king of Denmark. Like its namesake, ___________ technology unities separate entities - it unites mobile devices, PCs, and accessories under a single communication standard. Most ________ devices require close proximity to form a connection.
ANT+
________ technology is an ad-hoc wireless protocol operating at about 2.4 GHz. While _____ is a proprietary Garmin protocol, it is also open-source and therefore used by many manufacturers in addition to Garmin. ______ gathers and tracks information from sensors that are typically embedded in heart rate monitors, GPS devices, and other activity monitoring devices. _______ can also synch data from multiple devices for the same activity, such as a smartwatch, smartphone, bicycle computer, or fitness equipment.
ESS
a group of access points connected to the same LAN
Infrastructure WLAN
an intervening connectivity device (access point) accepts the signals from the nodes and re-transmits them to the rest of the network
control frame
frames related to medium access and data delivery - such as ACK and RTS/CTS
dead zone
gaps in Wi-Fi coverage at your location
frame control field
holds information about the protocol in use, the type of frame being transmitted, whether the frame is part of a larger, fragmented packet, whether the frame is one that was reissued, what type of security the frame uses, etc....
MAC filtering
method to prevent an AP from authenticating any device whose MAC address is not listed by network admin
authentication
process of comparing and matching a client's credentials with the credentials in a client database to enable the client to log on to the network
guest network
smart security precaution - gives guests access to Internet through an open network without opening doors to entire LAN on the router
wireless analyzer (Wi-Fi analyzer)
software that can evaluate Wi-Fi network availability, optimize Wi-Fi signal settings, and help identify Wi-Fi security threats
Address 2 & Address 3 fields
the MAC address of the access points or intermediary device on the wireless network
BSSID
the identifier for the group of nodes that share the same access point
encryption
use of an algorithm to scramble data into a format that can be read only by reversing the algorithm - purpose is to keep information private
sequence control field
used to indicate how a large packet is fragmented for more reliable delivery
unidirectional antenna
used when a source needs to communicate with one destination - point-to-point link
omnidirectional antenna
used when many different receivers must be able to pick up the signal - point-to-multipoint links
Ad Hoc WLAN
wireless nodes transmit directly to each other via wireless NICs without and intervening connectivity device
