EMT Practice Test

1. Question Content...

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Question1: You support a WLAN using dual-band 802.11ac three stream access points. All access points have both the 2.4 GHz and 5 GHz radios enabled and use 40 MHz channels in 5 GHz and 20 MHz channels in 2.4 GHz. A manager is concerned about the fact that each access point is connected using a 1 Gbps Ethernet link. He is concerned that the Ethernet link will not be able to handle the load from the wireless radios.
What do you tell him?

Question2: You are troubleshooting a problem with interference from a non-802.11 device. Given that the device is not a WLAN device, you cannot use a protocol analyzer and have chosen to use a spectrum analyzer. You want to view the signal from the interfering device over time to see the activity that is generating.
What common spectrum analyzer view should you use for this analysis?

Question3: You are installing an AP to be used by 23 laptops. All laptops will connect on the 5 GHz frequency band. A neighbor network uses channels 1 and 6. What channel should be used for this AP and why?

Question4: Return Loss is the decrease of forward energy in a system when some of the power is being reflected back toward the transmitter.
What will cause high return loss in an RF transmission system, including the radio, cables, connectors and antenna?

Question5: Your manager asked you to locate a solution that allows for centralized monitoring of WLAN performance over time. He wants a single pane of glass for administration and monitoring of the solution. What do you recommend?

Question6: You are using a site survey tool for post-implementation validation. You have installed the appropriate adapter driver and imported a floor plan. Now, you want to take the next step in proper tool use. What must you do before gathering survey data after the floor plan is imported?

Question7: What is always required to establish a high quality 2.4 GHz RF link at a distance of 3 miles (5 kilometers)?

Question8: When a client station sends a broadcast probe request frame with a wildcard SSID, how do APs respond?

Question9: You are troubleshooting a client problem with a 2.4 GHz WLAN connection. The client is experiencing surprisingly low data rates during the work day. You analyze the workspace outside of business hours and detect a strong signal with a typical noise floor at the client location. During working hours, the user works with a laptop in the area and uses an external USB hard drive for continuous data access. The user also states that the laptop works as expected on her home network. The user working approximately 8 feet away from this client experiences no problems.
Based on this information, what is the likely cause of the problem?

Question10: What security solution is deprecated in the 802.11 standard and should never be used in any modern WLAN deployment?

Question11: You recently purchased four laptops containing dual-band 802.11ac adapters. The laptops can connect to your 2.4 GHz network, but they cannot connect to the 5 GHz network. The laptops do not show the 5 GHz SSIDs, which are different than the 2.4 GHz SSIDs. Existing devices can connect to the 5 GHz SSIDs with no difficulty. What is the likely problem?

Question12: Which one of the following 802.11 PHYs is more likely to be used in an industrial deployment but not likely to be used in standard office deployments?

Question13: What common feature of MDM solutions can be used to protect enterprise data on mobile devices?

Question14: You administer a small WLAN with nine access points. As a small business, you do not run a RADIUS server and use WPA2-Personal for security. Recently, you changed the passphrase for WPA2-Personal in all APs and clients. Several users are now reporting the inability to connect to the network at times and it is constrained to one area of the building. When using a WLAN scanner, you see that the AP covering that area is online and has a strong signal. No other changes have been made to the environment and all access points are the same model. What is the likely problem?

Question15: What Linux shell command can be used to view the hardware and PHY capabilities of a wireless adapter in detail including channel widths, output power settings, channels supported, and more?

Question16: A non-802.11 device is suspected of causing interference on the WLAN. You are not certain of the location or type of device. What is the best solution for locating this non-802.11 device?

Question17: What non-standard WLAN solution attempts to give a longer transmission windows to devices with higher data rates than devices with lower data rates?

Question18: When implementing PoE, what role is played by a switch?

Question19: In which plane of the three networking planes is an access point configured by a WLAN controller?

Question20: You are reconfiguring an AP to use the short guard interval. How long will the new guard interval duration be after the change?

Question21: You are attempting to locate the cause of a performance problem in two WLAN cells in a mostly overlapping coverage area. You note that one AP is on channel 1 and the other is on channel 2. When you document your findings, what term do you use to describe the problem in this configuration?

Question22: What security method is commonly used for VoIP handsets when the infrastructure does not support OKC or FT roaming?

Question23: When compared with legacy Power Save mode, how does VHT TXOP power save improve battery life for devices on a WLAN?

Question24: You administer a WLAN that offers a guest SSID of GUESTNWORK. Users connect to the GUESTNWORK SSID, but report that they cannot browse the Internet. The devices simply report no Internet connection. What common problem causes this scenario?

Question25: As an RF wave propagates through space, the wave front experiences natural expansion that reduces its signal strength in an area. What term describes the rate at which this expansion happens?

Question26: During a post-implementation survey, you have detected a non-802.11 wireless device transmitting in the area used by handheld 802.11g scanners. What is the most important factor in determining the impact of this non-802.11 device?

Question27: You are implementing a multi-AP WLAN and fast secure roaming is essential. Which one of the following methods is an IEEE 802.11 standard method for fast roaming?

Question28: You are troubleshooting an issue reported by several wireless users. The problem is contained to one cell (several users connected to the same AP). You manage the WLAN and no other network devices. After analysis it appears to be a switch problem. What action should be taken?

Question29: What is appended to the end of each 802.11 data frame after the payload?

Question30: Lynne runs a small hotel, and as a value added for his customers he has implemented a Wi-Fi hotspot.
Lynne has read news articles about how hackers wait at hotspots trying to take advantage of unsuspecting users. He wants to avoid this problem at his hotel.
What is an efficient and practical step that Lynne can take to decrease the likelihood of active attacks on his customers' wireless computers?

Question31: What factor is likely to cause the least impact on the application layer throughput of an 802.11n client station in a 2.4 GHz HT BSS?

Question32: You have been tasked with creating a wireless link between two buildings on a single campus. The link must support at least 150 Mbps data rates. What kind of WLAN technology role should you deploy?

Question33: The requirements for a WLAN you are installing state that it must support unidirectional delays of less than
150 ms and the signal strength at all receivers can be no lower than -67 dBm. What application is likely used that demands these requirements?

Question34: Option 43 must be configured to allow access points to locate controllers. In what network service should this option be configured?

Question35: You are planning for PoE in a standard office deployment. Which one of these devices is least likely to be a PoE PD?

Question36: To ease user complexity, your company has implemented a single SSID for all employees. However, the network administrator needs a way to control the network resources that can be accessed by each employee based in their department.
What WLAN feature would allow the network administrator to accomplish this task?

Question37: You are deploying a WLAN with the access points configured for 10 mW of output power on the 2.4 GHz radios and 20mW of output power on the 5GHz radios. Some semi-directional antennas are also in use.
What kind of deployment is described?

Question38: You were previously onsite at XYZ's facility to conduct a pre-deployment RF site survey. The WLAN has been deployed according to your recommendations and you are onsite again to perform, a post- deployment validation survey.
When performing this type of post-deployment RF site survey voice over Wi-Fi, what is an action that must be performed?

Question39: You manage a WLAN with 100 802.11ac access points. All access points are configured to use 80 MHz channels. In a particular BSS, only 40 MHz communications are seen. What is the likely cause of this behavior?

Question40: What is the most effective method of testing roaming in relation to 802.11 VoIP handsets?

Question41: You are troubleshooting a WLAN problem and you suspect hidden node as the cause. What should you look for in a protocol analyzer?

Question42: Three access points are used within a facility. One access point is on channel 11 and the other two are on channel 1. The two access points using channel 1 are on either side of the access point using channel 11 and sufficiently apart so that they do not interfere with each other when they transmit frames. Assuming no other APs are in the vicinity, is CCI still a possibility in this network and why?

Question43: ABC Company is planning a point-to-multipoint bridge deployment with standalone (autonomous) 802.11 bridge units. 802.1X/EAP will be used for bridge authentication. A Linux-based RADIUS server will be used for authentication. What device in the bridge implementation acts as the 802.11X Authenticator?

Question44: A dual-band 802.11ac AP must be powered by PoE. As a class 4 device, what power level should be received at the AP?

Question45: The center frequency of channel 1 in the 2.4 GHz band is 2.412 GHz (2412 MHz). What is the center frequency of channel 4?

Question46: You have received a report of poor wireless connections on the third floor of a building under your administration. Three individuals have reported the problem. Apparently, the connections are reporting a strong signal, but the users cannot access the Internet. With the problem identified, what is the next logical step in the troubleshooting process?

Question47: When an ACK frame is not received by the transmitting STA, what is assumed?

Question48: What 802.11 network configuration would result in multiple stations broadcasting Beacon frames with the same BSSID but with different source addresses?

Question49: When using a spectrum analyzer to look for non-Wi-Fi interference sources, you notice significant interference across the entire 2.4 GHz band (not on a few select frequencies) within the desktop area of a user's workspace, but the interference disappears quickly after just 2 meters. What is the most likely cause of this interference?

Question50: A WLAN is implemented using wireless controllers. The APs must locate the controllers when powered on and connected to the network. Which one of the following methods is commonly used to locate the controllers by the APs?

Question51: What cipher suite is specified by the 802.11-2016 standard and is not deprecated?

Question52: In an 802.11 2.4 GHz system, what 22 MHz channels are considered non-overlapping?

Question53: A standard PoE injector is used to power an access point requiring 802.3at. CAT6 cabling is in use. What is the maximum distance supported between the access point and the Ethernet switch with the use of a midspan power injector?

Question54: What statement about 802.3, Clause 33 Power over Ethernet is true?

Question55: What statement describes the authorization component of a AAA implementation?

Question56: In WLAN security, what authentication method always creates Layer 2 dynamic encryption keys?

Question57: You are the network administrator for ABC Company. Your manager has recently attended a wireless security seminar. The seminar speaker taught that a wireless network could be hidden from potential intruders if you disable the broadcasting of the SSID in Beacons and configured the access points not to respond to Probe Request frames that have a null SSID field.
Your manager suggests implementing these security practices. What response should you give to this suggestion?

Question58: What is the final step in an effective troubleshooting process?

Question59: You are managing a wireless access point in autonomous mode using the Web based interface. You capture traffic during this management task and notice that you can see the HTML code of the Web pages for access point management. What error in administration could be the cause of the security concern?

Question60: What primary metric of scanning can stations use to select the best AP for connectivity to the desired BSS?

Question61: You are deploying a WLAN monitoring solution that utilizes distributed sensor devices. Where should sensors be deployed for best results?

Question62: What statement about the IEEE 802.11-2016 QoS facility is true?

Question63: You are tasked with performing a throughput test on the WLAN. The manager asks that you use open source tools to reduce costs. What open source tool is designed to perform a throughput test?

Question64: Which unit of measurement is an absolute unit that is used to quantify received signal power levels on a logarithmic scale?

Question65: You are performing a post implementation validation survey. What basic tool can be used to easily locate areas of high co-channel interference?

Question66: You are attempting to explain RF shadow and how it can cause lack of coverage. What common building item frequently causes RF shadow and must be accounted for in coverage plans?

Question67: You are troubleshooting a controller-based AP that is unable to locate the controller. DHCP is not used and the controller is located at 10.10.10.81/24 while the AP is on the 10.10.16.0/24 network. What should be inspected to verify proper configuration?

Question68: You are reporting on the RF environment in your facility. The manager asks you do describe the noise floor noted on the report. Which of the following is the best explanation?

Question69: What statement about 802.11 WLAN performance is true?

Question70: A natural disaster has occurred in a remote area that is approximately 40 miles from the response team headquarters. The response team must setup a local wireless network using 802.11 WLAN access points.
What is the best method, of those listed, for implementation of a network backhaul for communications across the Internet in this scenario?