Wireless Networking Final

What are some problems that can occur when an indoor access point is transmitting at full power? (Choose all that apply) Answer Co-Channel Interference Answer Hidden Node Intersymbol interference Sticky clients Band hopping

Answer Co-Channel Interference Answer Hidden Node Sticky clients

Which 802.11ax technology has the potential to decrease co-channel interference (CCI)?

BSS Color

Match the data units to their corresponding OSI layer.

Bits > Layer 1 Frames > Layer 2 Packets > Layer 3

This type of control frame is used to acknowledge Frame Bursts and Aggregate Frames.

Block Acknowledgements

When the guest wireless network is configured to prevent mobile devices from communicating with eachother, this is called? This configuration can help prevent peer-to-peer attacks.

Client Isolation

In regards to network security, CIA stands for?

Confidentiality, Integrity, Availability

Which of the following is typically the most important design goal when designing a warehouse WLAN?

Coverage

On which of these transportation networks is satellite a functional and likely solution for providing up-link to the Internet?

Cruise Ship

When implementing 802.11ac, the following must be considered with regards to the wired Ethernet infrastructure. (Choose 2) Etherenet speed / throughput capabilities Ethernet Switch Manufacturer 802.11ac requires fiber optic cable PoE capabilities 802.11ac requires shielded Cat6a cable

Etherenet speed / throughput capabilities PoE capabilities

Every broadcast frame on an 802.11 wireless network requires an acknowledgement.

False

WIDS can detect an evesdropping attack.

False

WPA-Personal (also known as WPA-PSK) uses a pre-shared key and therefore has the same security issues as WEP which used shared key authentication.

False

This occurs when all client stations can communicate with the access point but one or more client stations cannot hear transmissions from other client stations due to an obstacle or large distances between client stations.

Hidden Node

Hotels and hospitality environments often present which of the following challenges?

High aesthetic demands

Warehouses and manufacturing environments often present which of the following challenges?

High levels of reflection and RF Interference

Which type of organization often has a person responsible for keeping track of frequency usage inside the organization?

Hospital

In a PoE implementation, this device is often used to add PoE capabilities when the existing network switch is not capable of providing PoE:

Midspan Power Sourcing Equipment

This platform is used to manage, monitor, and secure mobile devices within an organization. With this platform, IT administrators can create policies for mobile devices which are enrolled to the system. These policies ensure that the mobile devices and users adhere to corporate security standards and usage policies.

Mobile Device Management

This occurs during the contention window and prevents stations which are transmitting the same type of frame (using the same IFS), from causing a collision.

Random Backoff Timer

This was introduced in 802.11n for use during frame bursts in greenfield mode, but is now obsolete in 802.11ac.

Reduced Interfame Space

This power save mode is used by MIMO devices and allows the device to power down all but one radio in the radio chain.

SM Power Save

Which one of these wireless security implementations would typically be used on a guest network or public hostspot network?

Open System

This sublayer exists at layer one and is responsible for modulating the data onto the physical medium. The physical modulation at this sub-layer will be determined by the physical medium type (Copper, Fiber Optic, Wireless, etc).

PMD

This is a method which can be implemented to ensure that clients stations meet a minimum standard, such as up-to-date antivirus definitions, before being allowed access to the network.

Posture Assessment

In a PoE implementation, the device which consumes power is called:

Powered Device

Hospitals often present which of the following challenges?

Sensitive equipment which can be disrupted by 802.11 frequencies

This feature of 802.11n and 802.11ac reduces the space between symbol transmissions resulting in increased throughput.

Short Guard Interval

Introduced in 802.11n, this technology utilizes multiple transmitters and receivers to increase resiliency and throughput. Unlike switched diversity, this technology leverages multipath instead of attempting to mitigate it.

Single User MIMO

The proper tool to discover and measure RF interference is:

Spectrum Analyzer

With traditional 802.11 Power Save Mode, client stations check this when they wake up to see if the access point has buffered unicast traffic that is pending transmission to the client station.

Traffic Indication Map (TIM)

These frames are used to allocate resource units for multi-user communication within OFDMA.

Trigger Frames

802.11 stations cannot positively identify collisions on the wireless medium.

True

Every unicast frame on an 802.11 wireless network requires an acknowledgement.

True

WIDS can detect rouge wireless access points.

True

When using an unencrypted public hotspot, which of the following can provide data confidentiality for the end user?

Use a VPN

WPA-Personal (also known as WPA-PSK) uses a pre-shared key and therefore is vulnerable to brute force or dictionary based authentication attacks. The best way to mitigate this risk is to do the following.

Use strong and complex randomly generated pre-shared keys which do not contain dictionary words

This layer 2 technology can be used to segregate logical networks within the network. This should be used to separate insecure network segments, such as guest networks, from secure network segments.

VLAN

This solution can be used by wireless users to protect from evesdropping attacks when using unsecured public hostspots or guest networks.

VPN

Which of the following uses a static encryption key that is the same for all wireless users on the network?

WEP

This power save mode is used buy Wireless QoS capable devices and allows the client application to control doze and awake periods. This power save method is not dependent on the TIM field in the beacon frame and uses trigger frames instead of PS Poll frames.

WMM Power Save

Which of the following wireless security implementations utilizes unique authentication credentials for each wireless user?

WPA-Enterprise

Which of these wireless security implementations utilizes a single pre-shared key used by all wireless users for authentication?

WPA-Personal

Which of the following use a per session, per user, dynamic encryption key called a Pairwise Transient Key? (Choose all that apply) WPA-Personal WEP WPA-Enterprise Dynamic WEP WPA-PSK (Pre-Shared Key)

WPA-Personal WPA-Enterprise WPA-PSK (Pre-Shared Key)

Which of the following are fully compliant with the IEEE 802.11i standard? (Choose all that apply) BSA WPA2 WPA WEP

WPA2

Using channel bonding, the maximum channel bandwidth for 802.11ac is?

160 MHz

802.11n may use which frequency bands? (Select all that Apply) 2.4GHz 900 MHz 5.0 GHz 1.2 GHz

2.4GHz 5.0 GHz

Within 802.11ax, OFDMA uses how many subcarriers within a 20MHz wide channel? These subcarriers may also be called tones.

256

At maximum data rate, 802.11ac uses which modulation scheme?

256-QAM

The maximum number of spatial streams supported by 802.11ac clients is?

4

The maximum number of spatial streams supported by 802.11n is?

4

Using channel bonding the maximum channel bandwidth for 802.11n is?

40 MHz

Mobile office networking and temporary offices can often benefit greatly from which of the following WAN technologies?

4G LTE

802.11ac may use which frequency bands? (Choose all that apply) 5.0 GHz 2.4 GHz 900 MHz 1.2 GHz

5.0 GHz

The maximum data rate for 802.11n is? 100 Mbps 600 Mbps 300 Mbps 200 Mbps

600 mbps

At maximum data rate 802.11n uses which modulation scheme?

64-QAM

The maximum number of spatial streams supported by 802.11ac access points is?

8

This PoE Standard was approved in 2003 and is capable of providing approximately 15 watts of power.

802.3af

This PoE Standard was ratified in 2009 and is capable of providing approximately 30 watts of power.

802.3at

Within 802.11ax, what is the maximum number of simultaneous clients supported by a OFDMA using a 20MHz channel.

9 clients

This aggregate frame type is supported in 802.11n but all frames are transmitted using this aggregate frame format in 802.11ac.

A-MPDU

Match each frame with the associated frame type:

ACK > Data Frames Beacon > Control Frames RTS/CTS > Data Frames Authentication > Management Frame

Which method is used by wireless stations to determine that a collision may have occurred and that a layer 2 re transmission is necessary.

ACK frames / Acknowledgement Timers

The following are possible ways to mitigate hidden node issues. (Choose Three) Increase the power of the access point Decrease power on the hidden node station Add additional access points Move the hidden node client station(s) Remove the obstacle

Add additional access points Move the hidden node client station(s) Remove the obstacle

Name a unique consideration when deploying a wireless network in a hotel or other hospitality business. (Choose the best answer) Segmentation Aesthetics User Management Roaming

Aesthetics

Which method is used by wireless stations to coordinate access to the wireless medium?

CSMA/CA

A web based interface which requires guest users to authenticate or agree to an Acceptable Use Policy (AUP) prior to allowing access to the public Internet is called?

Captive Web Portal

Which of the following is least likely to be offered by a hotspot provider?

Data Encryption

The following is the most appropriate solution for mismatched power issues.

Decrease cell sizes and add more access points

This is the method used by 802.11 stations for CSMA/CA. While the other method is optionally supported by 802.11, no wireless vendors have implemented it.

Distributed Coordination Function (DCF)

This value is read from the frame header and notifies wireless stations that a conversation will be taking place for a specified period of time. All stations must count down the specified value and cannot proceed with medium contention until this timer is zero.

Duration / ID Field

This is a method by which employees can create user IDs for guest users.

Employee Sponsorship

Hotspot 2.0 provides which advantage for guest wireless network implementations?

Encrypted Guest Access

In a PoE implementation, a PoE capable network switch which provides power to network devices is called:

Endpoint Power Sourcing Equipment

This timer in CSMA/CA allows control frames, such as ACK frames, priority access to the wireless medium over typical data frames.

Interframe Space (IFS)

Corporations often install wireless networks to provide which of the following capabilities? (Choose Three) Highest-speed network access when compared to wired networking Internet access for visitors and guests The ability to add network access in areas where wired connections are unavailable End User Mobility

Internet access for visitors and guests The ability to add network access in areas where wired connections are unavailable End User Mobility

Which of the following is typically the main purpose of a SOHO 802.11 network?

Internet gateway

What are some of the negative effects of layer 2 re-transmissions (Choose all that apply) Jitter Excessive MAC sublayer overhead Increased latency Decreased latency Decreased range

Jitter Excessive MAC sublayer overhead Increased latency

Layer 2 re-transmissions occur when frames become corrupted. What are some of the causes of layer 2 re-transmissions. (Choose all that apply) Co-channel interference Low SNR Adjacent channel interference RF Interference High SNR

Low SNR Adjacent channel interference RF Interference

What is the largest problem with using MAC Address Filters for wireless network authentication?

MAC addresses are easily spoofed

Within 802.11ax, this technology supports silmultanious multi-user transmissions through the use of multiple spatial streams and requires the use of transmit beamforming.

MU-MIMO

Introduced with 802.11ac, this allows access points to communicate with up to 4 client stations simultaneously using two spatial streams per client.

Multiuser MIMO

Normal RF interference is typically

Narrow Band

Within 802.11ax this feature subdivides the channel to support simultaneous multi-user transmissions of small frames. This feature creates a more efficient use of the channel and is optimal for smaller frames which account for up to 80% of WiFi transmissions.

OFDMA

WPA offers which of the following encryption protocols? (Choose All That Apply) AES DES 3DES TKIP

TKIP

WPA2 offers which of the following encryption protocols? (Choose All That Apply) TKIP AES DES 3DES

TKIP AES

Why would TKIP/RC4 be used in a modern wireless network implementation?

TKIP/RC4 is a stream cipher and is more appropriate for VoIP implementations

Which 802.11ax technology defines new power-saving capabilities that could be beneficial for IoT devices?

Target Wake Time

Why is SSID cloaking (hidden SSID) an ineffective form security?

The SSID can be easily found by eavesdropping