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Aruba ACMP practice questions

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Question 1Plan and design the wireless network (RF planning, coverage and capacity requirements)

A radio signal measured at 20 dBm corresponds to what transmit power in milliwatts?

  1. 100 mW Correct answer.
  2. 200 mW
  3. 20 mW
  4. 10 mW

Explanation

dBm is a logarithmic power unit, where dBm = 10 × log10(mW). Solving 10 × log10(100) = 20 shows that 20 dBm equals 100 mW. Each 10 dB step represents a tenfold change in power.

Question 2Plan and design the wireless network (RF planning, coverage and capacity requirements)

In the 2.4 GHz band, which set of channels is conventionally non-overlapping in North America?

  1. Channels 2, 7, and 12
  2. Channels 1, 6, and 11 Correct answer.
  3. Channels 1, 4, and 8
  4. Channels 1, 5, and 9

Explanation

2.4 GHz channels are spaced 5 MHz apart while a channel occupies about 22 MHz. Only 1, 6, and 11 are far enough apart to avoid overlapping spectrum in North America.

Question 3Plan and design the wireless network (RF planning, coverage and capacity requirements)

In free space, doubling the distance between an AP and a client increases path loss by approximately how many dB?

  1. 6 dB Correct answer.
  2. 20 dB
  3. 10 dB
  4. 3 dB

Explanation

Free-space path loss rises with 20 × log10(distance). Doubling distance therefore adds 20 × log10(2), which is about 6 dB.

Question 4Plan and design the wireless network (RF planning, coverage and capacity requirements)

When planning a WLAN for voice, what minimum RSSI at the cell edge is commonly recommended?

  1. -75 dBm
  2. -80 dBm
  3. -72 dBm
  4. -67 dBm Correct answer.

Explanation

Voice clients need roughly -67 dBm or better at the cell edge to keep retries low and latency bounded. Designing to a stronger target such as -65 dBm adds margin for fading.

Question 5Plan and design the wireless network (RF planning, coverage and capacity requirements)

What cell overlap between adjacent APs is typically recommended to support seamless roaming?

  1. 50 to 60 percent
  2. 15 to 20 percent Correct answer.
  3. 80 to 90 percent
  4. 0 to 5 percent

Explanation

Adjacent cells should overlap enough for a client to roam before the signal degrades, typically 15 to 20 percent. Too little overlap causes sticky clients and dropped sessions.

Question 6Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which design action most directly increases capacity in a dense office?

  1. Disabling the 5 GHz radios to reduce noise
  2. Raising transmit power on all access points
  3. Adding APs and lowering transmit power Correct answer.
  4. Bonding 2.4 GHz channels to 40 MHz

Explanation

Capacity scales with the number of cells, so adding APs at lower power creates smaller cells and more reuse. Raising power on existing APs increases co-channel interference without adding capacity.

Question 7Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which statement about DFS channels in the 5 GHz band is correct?

  1. DFS channels are reserved for outdoor bridging only
  2. DFS channels are limited to 2.4 GHz operation
  3. DFS channels cannot be used with 80 MHz widths
  4. The AP vacates the channel when radar is detected Correct answer.

Explanation

DFS channels are shared with radar systems, so an AP must detect radar and move off the channel. This can cause a brief outage while the AP selects a new channel.

Question 8Plan and design the wireless network (RF planning, coverage and capacity requirements)

An antenna rated 6 dBi is compared with one rated 3 dBi. What is the difference in gain?

  1. 3 dB Correct answer.
  2. 2 dB
  3. 6 dB
  4. 9 dB

Explanation

Antenna gain adds directly in dB, so 6 dBi minus 3 dBi is a 3 dB increase. A 3 dB gain doubles the radiated power in the favored direction.

Question 9Plan and design the wireless network (RF planning, coverage and capacity requirements)

An AP transmits at 18 dBm into a 6 dBi antenna with 3 dB of cable loss. What is the EIRP?

  1. 24 dBm
  2. 27 dBm
  3. 15 dBm
  4. 21 dBm Correct answer.

Explanation

EIRP equals transmit power plus antenna gain minus cable loss: 18 + 6 - 3 = 21 dBm. Regulatory limits apply to this calculated EIRP, not to radio power alone.

Question 10Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which survey places a real AP at each candidate location to measure actual coverage?

  1. Predictive
  2. Spectrum analysis
  3. AP-on-a-stick Correct answer.
  4. Passive

Explanation

An AP-on-a-stick survey places a real AP at each candidate location and measures actual coverage. This validates mounting, attenuation, and cell overlap before final installation.

Question 11Plan and design the wireless network (RF planning, coverage and capacity requirements)

A signal measures -67 dBm and the noise floor is -95 dBm. What is the SNR?

  1. 38 dB
  2. 18 dB
  3. 162 dB
  4. 28 dB Correct answer.

Explanation

SNR is signal minus noise in dB: -67 - (-95) = 28 dB. A 28 dB SNR is generally sufficient for high data rates and voice.

Question 12Plan and design the wireless network (RF planning, coverage and capacity requirements)

What is the main effect of changing a 5 GHz channel from 20 MHz to 40 MHz?

  1. It reduces co-channel interference
  2. It doubles the number of available channels
  3. Higher peak rate, fewer reuse options Correct answer.
  4. It lowers the noise floor by 3 dB

Explanation

Wider channels double the peak data rate but consume two 20 MHz channels, reducing the number of reusable channels. That raises co-channel interference risk in dense deployments.

Question 13Plan and design the wireless network (RF planning, coverage and capacity requirements)

What is the primary way to reduce co-channel interference in a multi-AP deployment?

  1. Increasing transmit power on every AP
  2. Planning adequate channel reuse distance Correct answer.
  3. Enabling 802.11b data rates
  4. Using wider channel bonds

Explanation

Co-channel interference is controlled by physical separation and channel reuse planning. Higher power and wider channels increase the interference footprint.

Question 14Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which approach is best for a high-density auditorium with hundreds of seated clients?

  1. A single AP with 80 MHz channels
  2. APs mounted at floor level behind seats
  3. One high-power AP in the center of the room
  4. Many low-power APs with directional antennas Correct answer.

Explanation

High-density rooms need many small cells with low power and directional patterns to serve clients without overshooting. Disabling low rates also reduces airtime overhead.

Question 15Plan and design the wireless network (RF planning, coverage and capacity requirements)

How many non-DFS 20 MHz channels are available in the US 5 GHz UNII-1 and UNII-3 bands combined?

  1. 8
  2. 4
  3. 9 Correct answer.
  4. 13

Explanation

In the US, UNII-1 provides four 20 MHz channels and UNII-3 provides five, for nine non-DFS channels. DFS channels add more but require radar detection.

Question 16Plan and design the wireless network (RF planning, coverage and capacity requirements)

For a point-to-point outdoor link, what minimum clearance of the first Fresnel zone is recommended?

  1. 60 percent Correct answer.
  2. 100 percent
  3. 40 percent
  4. 20 percent

Explanation

At least 60 percent of the first Fresnel zone should be clear of obstructions for a reliable outdoor link. More clearance improves signal and reduces multipath fading.

Question 17Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which material attenuates a 5 GHz signal most strongly?

  1. Single-pane glass window
  2. Hollow wood door
  3. Interior drywall partition
  4. Rebar-reinforced concrete wall Correct answer.

Explanation

Concrete with rebar contains metal and dense material that absorbs and reflects 5 GHz energy strongly. Drywall, glass, and wood attenuate far less.

Question 18Plan and design the wireless network (RF planning, coverage and capacity requirements)

A 4x4:4 AP serves a 2x2 client. How many spatial streams can that client use at most?

  1. 4
  2. 8
  3. 1
  4. 2 Correct answer.

Explanation

Spatial streams are limited by the smaller of the AP and client radio chains, so a 2x2 client uses two streams. The extra AP chains improve diversity but do not create extra streams for that client.

Question 19Plan and design the wireless network (RF planning, coverage and capacity requirements)

What is the purpose of Aruba ARM in a wireless design?

  1. It balances clients across SSIDs
  2. Automated channel and power Correct answer.
  3. It encrypts management frames
  4. It enforces role-based access

Explanation

ARM continuously monitors the RF environment and adjusts channel and power to reduce interference. It is not an encryption, SSID balancing, or role feature.

Question 20Plan and design the wireless network (RF planning, coverage and capacity requirements)

What does band steering do for dual-band clients?

  1. Steers dual-band clients to 5 GHz Correct answer.
  2. It forces all clients to 2.4 GHz
  3. It doubles the channel width on 5 GHz
  4. It disables 802.11ax on 5 GHz

Explanation

Band steering nudges capable clients to 5 GHz, which has more channels and less interference. This leaves 2.4 GHz for legacy and IoT devices.

Question 21Plan and design the wireless network (RF planning, coverage and capacity requirements)

Sixty clients each need 2 Mbps of throughput, and an AP delivers 100 Mbps of usable capacity. What is the minimum number of APs for capacity?

  1. 2 Correct answer.
  2. 4
  3. 1
  4. 3

Explanation

Total demand is 60 × 2 = 120 Mbps. At 100 Mbps usable per AP, two APs are needed for capacity, before adding redundancy.

Question 22Plan and design the wireless network (RF planning, coverage and capacity requirements)

Why do designers often disable the lowest 802.11b data rates?

  1. It increases the coverage range of each AP
  2. Less management overhead, smaller cells Correct answer.
  3. It doubles the available 2.4 GHz channels
  4. It raises the noise floor for neighboring cells

Explanation

Disabling the lowest rates removes slow clients that consume excessive airtime and shrinks the effective cell. Coverage still exists at higher rates, but edge clients may drop.

Question 23Plan and design the wireless network (RF planning, coverage and capacity requirements)

What is the best mounting position for an office ceiling AP?

  1. Centered on the ceiling, unobstructed Correct answer.
  2. Against an exterior concrete wall
  3. On the floor beneath a desk
  4. Inside a metal enclosure overhead

Explanation

Ceiling-center mounting gives a symmetric radiation pattern and clear paths to clients. Metal enclosures and walls block or distort the signal.

Question 24Plan and design the wireless network (RF planning, coverage and capacity requirements)

What does a predictive site survey rely on?

  1. Measuring live RF with a laptop and adapter
  2. Modeling from floor plans and attenuation values Correct answer.
  3. Analyzing spectrum analyzer traces only
  4. Using an AP at each proposed location

Explanation

A predictive survey uses floor plans, wall attenuation values, and AP antenna patterns to model coverage before equipment is installed. It is faster but must be validated later.

Question 25Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which statement about 6 GHz operation is correct?

  1. A mandatory 80 MHz width for every client
  2. Heavy overlap with the 5 GHz UNII bands
  3. No support for band steering on the AP
  4. Many clean channels and no legacy clients Correct answer.

Explanation

6 GHz offers many more 20 MHz channels and only supports Wi-Fi 6E and later clients, so legacy interference is absent. That makes it valuable for capacity planning.

Question 26Plan and design the wireless network (RF planning, coverage and capacity requirements)

In RF planning, what does RSSI represent at a survey measurement point?

  1. Received signal strength Correct answer.
  2. Frame retry percentage
  3. Channel width in megahertz
  4. Client throughput demand

Explanation

RSSI is a relative measure of the received RF signal level at the measurement point. Designers compare RSSI against targets such as -67 dBm at the cell edge to judge coverage. It is not a throughput, channel-width, or retry metric.

Question 27Plan and design the wireless network (RF planning, coverage and capacity requirements)

For a voice-over-Wi-Fi design, what cell-to-cell overlap is commonly targeted at the coverage boundary?

  1. 50% to 60%
  2. 100%
  3. 0% to 5%
  4. 15% to 20% Correct answer.

Explanation

A 15% to 20% overlap gives clients enough secondary coverage to roam before the primary signal becomes unusable. More overlap than that increases co-channel interference without a meaningful roaming benefit.

Question 28Plan and design the wireless network (RF planning, coverage and capacity requirements)

What does a passive site survey primarily record?

  1. The number of clients associated to each AP
  2. The configuration of each AP radio
  3. The throughput of a client associated to each AP
  4. RF signal levels and interference at survey points Correct answer.

Explanation

A passive survey listens to the RF environment without associating a client or generating test traffic. It records signal levels, noise, and interference from all detectable sources. Active surveys are used when association and performance testing are required.

Question 29Plan and design the wireless network (RF planning, coverage and capacity requirements)

Under free-space path loss, how much additional loss occurs when the distance between transmitter and receiver doubles?

  1. 4 dB
  2. 3 dB
  3. 5 dB
  4. 6 dB Correct answer.

Explanation

Free-space path loss follows an inverse-square relationship with distance. Doubling distance adds 20 log10(2), which is approximately 6 dB. This rule is useful for quick range estimates before a detailed survey.

Question 30Plan and design the wireless network (RF planning, coverage and capacity requirements)

In a regulatory domain, what does the maximum EIRP limit constrain?

  1. Only the transmit power setting on the AP radio
  2. The number of clients that may associate to the AP
  3. The combined radio power, antenna gain, and cable loss Correct answer.
  4. Only the antenna gain rating of the AP

Explanation

EIRP is calculated from transmit power plus antenna gain minus cable loss, so the regulatory cap applies to the radiated result rather than to one component alone. An AP with high antenna gain may need lower radio power to stay within the limit. Client association limits are unrelated to RF regulations.

Question 31Plan and design the wireless network (RF planning, coverage and capacity requirements)

In a warehouse with very high ceilings, why might a directional antenna with downtilt be chosen over a wide-angle ceiling antenna?

  1. To allow the AP to use DFS channels
  2. To focus coverage in aisles and limit cell overlap Correct answer.
  3. To increase the number of spatial streams
  4. To increase the maximum EIRP allowed by regulations

Explanation

High ceilings make wide-angle antennas cover large overlapping areas, which can raise co-channel interference. A directional pattern with downtilt focuses energy toward the aisle and limits spill into neighboring cells. Spatial streams, DFS eligibility, and regulatory EIRP caps are not improved by downtilt.

Question 32Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which channel utilization reading most strongly suggests that a 5 GHz cell is approaching a capacity limit and should be split?

  1. 75% Correct answer.
  2. 5%
  3. 30%
  4. 10%

Explanation

Sustained channel utilization above roughly 70% leaves little airtime headroom for retries, management traffic, and latency-sensitive applications. A cell at 75% utilization is therefore a strong candidate for an additional AP or load balancing. Readings of 5% to 30% generally indicate available capacity.

Question 33Plan and design the wireless network (RF planning, coverage and capacity requirements)

For latency-sensitive voice over Wi-Fi, which minimum SNR is a common design target?

  1. 5 dB
  2. 25 dB Correct answer.
  3. 10 dB
  4. 15 dB

Explanation

Voice benefits from a higher SNR because it supports more robust modulation and fewer retries. A common target is about 25 dB SNR at the coverage boundary. Lower values may still pass data but often produce poor call quality.

Question 34Plan and design the wireless network (RF planning, coverage and capacity requirements)

Which antenna specification describes the angular width of coverage in the horizontal plane?

  1. Antenna gain
  2. Azimuth beamwidth Correct answer.
  3. Voltage standing wave ratio
  4. Polarization

Explanation

Azimuth beamwidth is the horizontal-plane angle over which the antenna radiates effectively. It helps the designer predict coverage shape and overlap between APs. Gain, polarization, and VSWR describe other antenna characteristics.

Question 35Plan and design the wireless network (RF planning, coverage and capacity requirements)

What distinguishes an active site survey from a passive survey?

  1. It records only the noise floor
  2. It requires no client device
  3. It uses predictive modeling instead of measurements
  4. It associates a client and tests performance Correct answer.

Explanation

An active survey uses an associated client to exchange test traffic and measure throughput, latency, and roaming behavior. A passive survey only listens to the RF environment. Predictive modeling is a separate design method that does not measure the installed RF environment.

Question 36Plan and design the wireless network (RF planning, coverage and capacity requirements)

Two outdoor bridges are aligned, but one uses vertical polarization and the other uses horizontal polarization. What is the most likely result?

  1. A small increase in EIRP
  2. Automatic channel bonding
  3. No change in received signal
  4. Significant additional signal loss Correct answer.

Explanation

A polarization mismatch reduces the coupling between transmit and receive antennas, often by 20 dB or more depending on the antennas. Both ends should use the same polarization for a point-to-point link. EIRP and channel bonding are not improved by mismatched polarization.

Question 37Plan and design the wireless network (RF planning, coverage and capacity requirements)

An AP transmits at 20 dBm into a 10 dBi antenna with 3 dB of cable loss. The client has a 2 dBi antenna and 1 dB of cable loss. The client receiver sensitivity is -85 dBm, and a 10 dB fade margin is required. What is the maximum allowable path loss?

  1. 100 dB
  2. 113 dB
  3. 93 dB
  4. 103 dB Correct answer.

Explanation

AP EIRP is 20 + 10 - 3 = 27 dBm. The client receive system adds 2 - 1 = 1 dB, so received power is 28 dBm minus path loss. The required minimum received level is -85 + 10 = -75 dBm, giving a maximum path loss of 28 - (-75) = 103 dB.

Question 38Plan and design the wireless network (RF planning, coverage and capacity requirements)

A survey shows that clients at the cell edge receive -60 dBm from the AP, but the AP receives those same clients at -80 dBm. Which design action best improves link balance?

  1. Disable all data rates below 24 Mbps
  2. Increase AP transmit power to improve the client receive level
  3. Increase the channel width to 80 MHz
  4. Reduce AP power to bring downlink and uplink closer Correct answer.

Explanation

The asymmetry indicates that the AP downlink is much stronger than the clients uplink, often because AP power is higher than client power. Lowering AP power can bring the two link directions closer and encourage clients to roam at a more appropriate boundary. Wider channels and higher basic rates do not correct the power imbalance.

Question 39Plan and design the wireless network (RF planning, coverage and capacity requirements)

During a pre-installation spectrum analysis, a warehouse shows intermittent high-energy interference in the 2.4 GHz band. Which design action is most appropriate?

  1. Enable 40 MHz channels in 2.4 GHz for more throughput
  2. Raise 2.4 GHz AP power to override the interference
  3. Plan all APs on 2.4 GHz channels 1, 6, and 11
  4. Use 5 GHz access and move APs away from the interference Correct answer.

Explanation

Non-Wi-Fi interference is best avoided by moving client access to a cleaner band and physically separating APs from the source where possible. Raising power or widening channels can make the interference problem worse. A conventional 2.4 GHz channel plan does not remove an intermittent interferer.

Question 40Plan and design the wireless network (RF planning, coverage and capacity requirements)

A predictive design predicts -67 dBm at a location, but post-install validation measures -78 dBm. Which is the most likely cause?

  1. The DHCP lease time is set too short
  2. Underestimated wall attenuation in the model Correct answer.
  3. The AP is configured with a 20 MHz channel
  4. The client device is actively using band steering

Explanation

Predictive surveys depend on assumptions about wall materials, attenuation, and AP placement. If actual walls attenuate more than modeled, measured coverage will be weaker than predicted. Band steering, channel width, and DHCP lease time do not explain a large RSSI shortfall.

Question 41Deploy and configure mobility controllers and access points

An ArubaOS access point is on a subnet with no controller and no DNS record. The DHCP server returns a controller address in a vendor-specific option. Which DHCP option carries this value?

  1. 60
  2. 82
  3. 66
  4. 43 Correct answer.

Explanation

DHCP option 43 is the vendor-specific information option. Aruba APs use the value returned in option 43 to learn a controller address when DNS and ADP do not provide one.

Question 42Deploy and configure mobility controllers and access points

Which DNS name does an ArubaOS access point query by default when it tries to discover a controller through DNS?

  1. aruba-mobility
  2. aruba-ap
  3. aruba-controller
  4. aruba-master Correct answer.

Explanation

By default an ArubaOS AP resolves the DNS name aruba-master to find a controller or Mobility Master. The DNS server must return an A record for that name.

Question 43Deploy and configure mobility controllers and access points

Which statement describes Aruba Discovery Protocol (ADP)?

  1. The AP multicasts or broadcasts a request and a controller replies. Correct answer.
  2. The AP contacts Aruba Activate to obtain a controller certificate.
  3. The controller periodically pushes its management address to every AP.
  4. The AP uses LLDP-MED to learn the controller address from the switch.

Explanation

ADP is an Aruba-proprietary discovery method. The AP sends a discovery request on the local subnet, and a reachable controller answers with its address.

Question 44Deploy and configure mobility controllers and access points

In a traditional ArubaOS master-local topology, which controller is authoritative for the running configuration?

  1. The standby master only
  2. The local controller with the highest priority
  3. The master controller Correct answer.
  4. The controller that owns the AP's LMS address

Explanation

The master controller holds the authoritative configuration and synchronizes it to local controllers. Local controllers use that configuration to run their APs.

Question 45Deploy and configure mobility controllers and access points

What is the purpose of an AP group on an Aruba controller?

  1. It sets the radio channel for every AP to the same value.
  2. It lets APs share common virtual APs and profiles. Correct answer.
  3. It defines the DHCP scope used by clients of the APs.
  4. It assigns a single IP address to all APs in the group.

Explanation

An AP group is a logical grouping that binds APs to a common set of virtual APs and profiles. APs in the same group inherit those settings from the group configuration.

Question 46Deploy and configure mobility controllers and access points

Which command saves the running configuration to flash on an ArubaOS controller?

  1. write memory Correct answer.
  2. save running
  3. copy flash startup
  4. commit config

Explanation

ArubaOS uses write memory to copy the running configuration into flash. The startup configuration is read when the controller boots.

Question 47Deploy and configure mobility controllers and access points

What must be installed on an Aruba controller before it will terminate a new campus AP?

  1. A VIA license
  2. An RF Protect license
  3. A PEF license
  4. An AP license Correct answer.

Explanation

Each terminated campus AP consumes an AP license on the controller. PEF, RF Protect, and VIA licenses enable other features and do not by themselves allow an AP to join.

Question 48Deploy and configure mobility controllers and access points

Why should NTP be configured on an Aruba controller before deploying certificates?

  1. To synchronize AP channel assignments across the network.
  2. To distribute the controller's VRRP priority to peers.
  3. To provide DHCP relay for AP management VLANs.
  4. To keep the clock accurate for certificate validity checks. Correct answer.

Explanation

Certificate validation depends on an accurate system clock. NTP keeps the controller time synchronized so certificates are not seen as expired or not yet valid.

Question 49Deploy and configure mobility controllers and access points

Two Aruba controllers are configured as a master/standby pair. Which protocol gives them a shared virtual IP address for APs and administrators?

  1. VRRP Correct answer.
  2. OSPF
  3. HSRP
  4. GLBP

Explanation

Aruba master redundancy uses VRRP to present a virtual IP address shared by the master and standby. If the master fails, the standby takes over the virtual address.

Question 50Deploy and configure mobility controllers and access points

An AP is assigned to a controller through the LMS setting in its AP system profile. What does LMS identify?

  1. The DHCP server that leases the AP's address
  2. The RADIUS server that authenticates wireless clients
  3. The syslog server that stores AP logs
  4. The controller that terminates the AP's GRE tunnel Correct answer.

Explanation

LMS stands for local management switch and identifies the controller that terminates the AP's GRE tunnel. The backup LMS is used if that controller becomes unreachable.