Chapter 9 Review Questions

Which one of the following would be a likely cause of an older 802.11b device being unable to connect to the WLAN provided by an 802.11n AP in 2.4 GHz, if the signal strength in the area is -62 dBm and the noise floor is at -93 dBm?

• Insufficient SNR

• Weak signal

• Disabled data rates

• 802.11n APs cannot talk to 802.11b devices

A user reports that he is not seeing any wireless networks. Other clients near him see several wireless networks. What common problem should you check first?

• Low output power on the APs

• Disabled data rates

• NIC switch settings

• None of these

What tool is most useful for locating sources of non-Wi-Fi interference?

• Protocol analyzer

• Throughput tester

• Load tester

• Spectrum analyzer

A client near the lunch room using a 2.4 GHz device is experiencing intermittent connection problems. You suspect an interference problem. What kind of device may be causing the interference?

• 5 GHz HDMI wireless adapters

• Microwave oven

• 60 GHz 802.11ad devices

• TVHT devices

You are using 802.11n APs. Because of older devices, you are using WPAPersonal for security on all SSIDs. The 802.11n client devices are getting performance far below 802.11n capabilities. What is the problem?

• TKIP causes higher data rates to be disallowed

• Older devices cannot communicate with 802.11n networks

• The AP is not sufficiently powered by PoE

• None of these

You run seven SSIDs on each AP radio. The APs are 802.11ac APs, and all clients are 802.11n or 802.11ac clients. The data rates of 1 and 2 Mbps are disabled in all 2.4 GHz channels. The users complain that the performance is not acceptable. What single change would have the most significant positive impact on performance in this scenario?

• Enable the lower data rates

• Reduce the number of SSIDs

• Replace all 802.11n clients with 802.11a/g clients

• None of these options will improve performance

What is a potential solution to CCI problems?

• Install more APs on the same channel

• Increase the output power on all APs

• Change the channel on some APs

• None of these

What is required to configure the connection between the AP and the RADIUS server?

• Shared secret

• WPA2-Personal passphrase

• VLAN ID of the RADIUS server

• VLAN ID of the AP

When the 4-way handshake fails in a WPA2-Personal configuration, and the signal strengths to the client and to the AP are both good, what is the likely problem?

• Incorrect passphrase

• Incorrect fragmentation threshold

• Poor signal quality

• None of these

When a client OS update occurs, and the client can no longer connect to the WLAN, what is a possible problem that was introduced by the OS update?

• Non-Wi-Fi interference

• Insufficient DHCP pool size

• Faulty drivers

• None of these