Free CWNA Wireless Network Administrator MCQ Questions and Answers

Question 1

What is the center frequency of channel 40 in the U-NII-1 band?

Accepted Answer

5.2 GHz

Answer

The U-NII-1 band for 5 GHz Wi-Fi operates from 5.150 GHz to 5.250 GHz. Within this band, channels are spaced 20 MHz apart. Channel 36 has a center frequency of 5.180 GHz, and channel 40 is the next channel up. Therefore, the center frequency for channel 40 is 5.180 GHz + 20 MHz = 5.200 GHz, or 5.2 GHz.

Question 2

What are a few of layer two retransmissions' drawbacks?

Accepted Answer

Excessive MAC sublayer overhead

Answer

Layer two retransmissions, common in wireless networks like Wi-Fi, occur when data frames are not successfully received and acknowledged. While necessary for reliability, frequent retransmissions consume valuable airtime and processing power at the MAC sublayer. This leads to excessive overhead, reducing the network's overall efficiency and effective throughput, as more time is spent re-sending data rather than transmitting new information.

Question 3

Which of the subsequent statements is accurate?

Accepted Answer

When a downgrade occurs, the final received signal will never be stronger than the originally transmitted signal.

Answer

Signal 'downgrade' or 'fade' refers to the attenuation or weakening of a signal as it travels through a medium. Due to factors like absorption, reflection, and scattering, the received signal will always be weaker than the signal originally transmitted from the source. Therefore, a downgrade inherently means the final received signal cannot be stronger than the initial transmission.

Question 4

What is a PD Class 0 device's maximum power consumption?

Accepted Answer

12.95 W

Answer

According to the IEEE 802.3af Power over Ethernet (PoE) standard, a Powered Device (PD) classified as Class 0 is designed to draw a maximum power of 12.95 watts. This classification helps Power Sourcing Equipment (PSE) manage and allocate power efficiently to connected devices on the network.

Question 5

Which of these cryptographic techniques has been broken?

Accepted Answer

64-bit WEP

Answer

Wired Equivalent Privacy (WEP), particularly its 64-bit and 128-bit versions, is a deprecated and highly insecure encryption protocol for Wi-Fi. It has been widely broken due to fundamental cryptographic flaws, such as a weak initialization vector (IV) and vulnerabilities in its RC4 stream cipher implementation. These weaknesses allow attackers to easily recover the WEP key, rendering it ineffective for securing wireless communications.

CWNA - Wireless Network Administrator Practice Test

CWNA - Wireless Network Administrator Practice Test

Free CWNA Wireless Network Administrator MCQ Questions and Answers