Chapter 14: Wireless Networking Flashcards
The ____ standard defines both how wireless devices communicate and how to secure that communication.
802.11
What is Wi-Fi?
A family of protocols based on IEEE 802.11 standards.
What is a Wireless Access Point (WAP or AP)?
A device designed to interconnect wireless network nodes with wired networks and also bridges wireless network segments to wired network segments.
What is the 802.11 network operation mode where two or more devices communicate directly without any other intermediary hardware?
ad hoc mode
What is the 802.11 network operation mode that uses one or more WAPs?
infrastructure mode
Two or more wireless nodes communicating in ad hoc mode form a/an ____.
IBSS (Independent Basic Service Set)
A single WAP servicing a given area is called a/an ____.
BSS (Basic Service Set)
Multiple WAPs servicing an area is called a/an ____.
ESS (Extended Service Set)
What is a Basic Service Set Identifier (BSSID)?
The MAC address of a wireless access point.
What is a 32-bit identification string, sometimes called a network name, that’s inserted into the header of each data packet processed by a WAP (wireless access point)?
Service Set Identifier (SSID)
A spread-spectrum broadcasting method defined in the 802.11 standard that sends data out on different frequencies at the same time is called ____.
Direct-Sequence Spread-Spectrum (DSSS)
A spread-spectrum broadcasting method defined in the 802.11 standard that sends data on one frequency at a time, constantly shifting (or hopping) frequencies is called ____.
Frequency-Hopping Spread-Spectrum (FHSS)
A spread-spectrum broadcasting method defined in the 802.11 standard that combines the multiple frequencies of DSSS with FHSS’s hopping capability is called ____.
Orthogonal frequency-division multiplexing (OFDM)
Every Wi-Fi network communicates on a ____, a portion of the available spectrum.
channel
For the ____GHz band, the 802.11 standard defines 14 channels (US limits it to channels 1-11) of 20 MHz each.
2.4 GHz
What three channels in the 2.4 GHz band should be used on WAPs to avoid overlap?
1, 6, and 11
The versions of 802.11 that use the ____GHz and ____GHz bands use automatic channel switching and in general have around 40 different channels in the spectrums.
5.0 GHz, 6.0 GHz
Is radio a half-duplex or full-duplex transmission method?
half-duplex
Wi-Fi networks use carrier-sense multiple access with ____ (CSMA/____)?
collision avoidance (CSMA/CA)
Current CSMA/CA Wi-Fi devices use the ____ method for collision avoidance.
Distributed Coordination Function (DCF)
802.11-1997
Frequency
Spectrum
Speed
Range
Frequency: 2.4 GHz
Spectrum: DSSS
Speed: 2 Mbps
Range: ~300 feet
802.11b
Frequency
Spectrum
Speed
Range
Frequency: 2.4 GHz
Spectrum: DSSS
Speed: 11 Mbps
Range: ~300 feet
802.11a
Frequency
Spectrum
Speed
Range
Frequency: 5.0 GHz
Spectrum: OFDM
Speed: 54 Mbps
Range: ~150 feet
802.11g
Frequency
Spectrum
Speed
Range
Frequency: 2.4 GHz
Spectrum: OFDM
Speed: 54 Mbps
Range: ~300 feet
802.11n (Wi-Fi 4)
Frequency
Spectrum
Speed
Range
Frequency: 2.4 GHz
Spectrum: OFDM (QAM)
Speed: 100+ Mbps
Range: ~300 feet
____ is a feature in 802.11n and later WAPs that enables them to make multiple simultaneous connections called streams.
Multiple Input/Multiple Output (MIMO)
____ is a multiple-antenna technology in 802.11n WAPs that helps get rid of dead spots.
Transmit beamforming
802.11ac (Wi-Fi 5)
Frequency
Spectrum
Speed
Range
Frequency: 5.0 GHz
Spectrum: OFDM (QAM)
Speed: Up to 1 Gbps
Range: ~300 feet
____ is a feature of 802.11ac and later networking that enables a WAP to broadcast to multiple users simultaneously.
Multi-User MIMO (MU-MIMO)
802.11ax (Wi-Fi 6/6E)
Frequency
Spectrum
Speed
Range
Frequency: 2.4 GHz, 5.0 GHz, 6.0 GHz
Spectrum: OFDMA (1024 QAM)
Speed: Up to 10 Gbps
Range: ~300
What is Wi-Fi Protected Setup (WPS) and how does it work?
An automated and semi-automated process to connect a wireless device to a WAP. The process is either pressing a button on the device or pressing the button and then entering a PIN code.
____ is an early wireless security protocol for Wi-Fi that uses the RC4 encryption algorithm and is no longer used due to major security vulnerabilities.
WEP or Wired Equivalent Privacy
____ is a wireless security protocol that addresses weaknesses and acts as an upgrade to WEP. It also supports authentication using EAP.
WPA or Wi-Fi Protected Access
____ is an authentication wrapper that ___-compliant applications can use to accept one of many types of authentication. It is a general-purpose authentication wrapper mainly used in wireless networks.
EAP or Extensible Authentication Protocol
____ is a port-based authentication network access control mechanism for networks. It’s a complete authentication standard designed to force devices to go through a full AAA process to get anywhere past the interface on a network connection device such as a WAP (aka. network access server or NAS).
802.1X
____ is the consumer name for the IEEE 802.11i standard and the replacement for the WPA protocol. It uses the AES (Advanced Encryption Standard) algorithm.
WPA2
The process of using a mobile device’s built-in GPS capabilities and mobile networking capabilities to set geographical constraints on where the mobile device can be used is called ____.
geofencing
A switch that’s designed to handle a number of WAPs simultaneously and does the job of configuring them is called a/an ____.
wireless LAN controllers
____ is a method to load-balance wireless network clients associated with a single SSID. It distributes clients across many VLANs to avoid excessive levels of broadcast traffic.
VLAN pooling
____ is a standard that enables wireless access points (WAPs) to receive their power from the same Ethernet cables that transfer their data.
PoE or Power over Ethernet
An ____ radiates signal outward from the WAP in all directions.
omnidirectional antenna
The strengthening and focusing of radio frequency output from a WAP is called ____.
gain
An antenna that focuses all of its transmission energy in a single, relatively narrow direction is called ____. It’s design limits its ability to receive signals that are not aligned with the focused direction.
unidirectional
____ are flat, plate-shaped antennas that generate a half-sphere beam and are placed on walls.
Patch antennas
All radio signals have a property called ____, which describes the orientation of the radio waves which depends on the antenna.
polarization
____ wireless bridges can only communicate with a single other bridge and are used to connect two wired network segments.
Point-to-point
____ wireless bridges can talk to more than one other bridge at a time and can connect multiple network segments.
Point-to-multipoint
Wi-Fi ____ is the loss of packets due to an overworked WAP.
jitter
Wi-Fi ____ is when data stops moving for a moment due to a WAP being unable to do the work.
latency
____ is when the frequency of a band is filled to capacity due to a large number of devices using the same bandwidth.
Bandwidth saturation
What are the three physical problems that cause attenuation in Wi-Fi networks, the progressive loss of radio signal strength as the radio wave passes through different mediums?
Absorption
Reflection
Refraction
A ____ is a Wi-Fi network implementation used in some public facilities that directs attempts to connect to the network to an internal Web page for that facility; generally used to force terms of service on users.
captive portal
What is the progressive loss of radio signal passing through different media called?
Attenuation
Which technology enables use of a WAP without directly connecting the WAP to an AC power outlet?
PoE
What feature enabled 802.11n networks to minimize dead spots?
Transit beamforming
When setting up WPA2-PSK on your wireless network, you have the option to choose TKIP or AES. Which should you implement?
AES
What type of server supports EAP-encrypted passwords in accordance with the 802.1X standard?
RADIUS server
