2024年最新のJN0-251試験資料JN0-251学習ガイド [Q36-Q61]

2024年最新のJN0-251試験資料JN0-251学習ガイド

お手軽に合格させるJN0-251試験にはこちらが提供する問題集PDFテストエンジン

JN0-251試験は、ネットワークエンジニアリング、ワイヤレスネットワーク、またはクラウドコンピューティングのキャリアを追求したいITプロフェッショナルにとって必要な認定です。Mist AI技術は業界でますます人気が高まっており、組織はMist AIネットワークを展開し、管理するスキルと知識を持つITプロフェッショナルを求めています。JN0-251試験に合格し、JNCIA-MistAI認定を取得することは、ITプロフェッショナルがこの新興技術の専門知識を証明し、キャリアを進めるための優れた方法です。

質問 # 36
How does Mist detect rogue APs?

A. by using the AP's third dedicated radio
B. by using Radio Resource Management (RRM)
C. by using the AP's 5 GHz radio band
D. by using the AP's 2.4 GHz radio band

正解：C

質問 # 37
Which two Mist-supported APIs are considered event-driven? (Choose two.)

A. gRPC
B. WebSocket
C. Webhook
D. RESTful

正解：B、C

解説：
According to the web search results, WebSocket and Webhook are two Mist-supported APIs that are considered event-driven. Event-driven APIs are APIs that allow the server to push information to the client asynchronously, instead of requiring the client to poll the server for updates. Event-driven APIs can provide real-time data, decoupled systems, and improved scalability and performance.
WebSocket is a protocol that enables bidirectional communication between a client and a server over a single TCP connection1. WebSocket allows the server to send messages to the client without waiting for a request, and vice versa1. WebSocket can be used for event-driven APIs that require continuous and interactive data exchange, such as chat applications, online games, or live streaming1.
Webhook is a way of sending data from the server to a third-party application or service when a certain event occurs2. Webhook allows the server to notify the client about an event, such as a new order, a payment confirmation, or a user registration2. Webhook can be used for event-driven APIs that require one-way notifications or integrations with other platforms, such as Slack, Splunk, or ServiceNow2.

質問 # 38
Alert templates are assigned to sites in which area of the Mist GUI?

A. Alert Template Configuration
B. Site Group
C. Organization Settings
D. Site Configuration

正解：A

質問 # 39
Which two methods are supported for configuring a Mist environment? (Choose two.)

A. Use NETCONF.
B. Use the CLI.
C. Use the API.
D. Use the GUI.

正解：C、D

解説：
Reference:
According to the Juniper Networks documentation, there are two methods that are supported for configuring a Mist environment: using the API and using the GUI1. The API is a programmatic interface that allows you to interact with the Mist cloud and perform various tasks, such as creating and managing organizations, networks, sites, devices, users, and policies2. The API uses the RESTful architecture and supports JSON and XML formats2. You can use the API to automate and customize your Mist environment according to your needs2.
The GUI is a graphical user interface that allows you to access and manage your Mist environment through a web browser1. The GUI provides a user-friendly and intuitive way to configure and monitor your Mist devices, networks, sites, users, and policies3. The GUI also provides various features, such as dashboards, reports, analytics, insights, troubleshooting tools, and Marvis virtual network assistant3. You can use the GUI to easily and quickly set up and optimize your Mist environment3.

質問 # 40
What is an 802.11 management frame transmitted by an AP?

A. ping
B. echo request
C. keepalive
D. beacon

正解：D

質問 # 41
What are three alert levels used in the Mist UI? (Choose three.)

A. informational
B. critical
C. notice
D. warning
E. error

正解：A、B、D

質問 # 42
You are inviting a new administrator into a Mist organization.
In this scenario, which two roles are valid? (Choose two.)

A. Helpdesk
B. Network Admin
C. Standard
D. System Admin

正解：A、B

解説：
Reference:
According to the Administrator Roles page, there are five types of roles that can be assigned to users in a Mist organization: Super User, Network Admin, Helpdesk, Observer, and Installer4. Each type of role has different read and write capabilities for the organization and its sites4. Helpdesk and Network Admin are two of the valid roles that can be selected when inviting a new administrator into a Mist organization4. Standard and System Admin are not valid roles in Mist.

質問 # 43
Which statement is correct about Bluetooth and BLE?

A. Bluetooth and BLE are compatible.
B. BLE is a newer technology than Bluetooth.
C. Bluetooth and BLE use the same radio channels.
D. BLE is an upgrade to Bluetooth.

正解：C

解説：
The correct answer is B. Bluetooth and BLE use the same radio channels. Bluetooth and BLE are both wireless technologies that operate in the 2.4 GHz ISM band1. They use the same 40 channels, each with a bandwidth of 1 MHz2. However, Bluetooth and BLE are not compatible, as they use different protocols and modulation schemes2. BLE is a newer technology than Bluetooth, as it was introduced in 2010 as part of the Bluetooth 4.0 specification3. BLE is designed to be more energy-efficient and suitable for low-power devices that transmit small amounts of data3.

質問 # 44
You have just brought online a new site of AP43s. While verifying that everything looks good, you notice that all of the access points (APs) are reporting "insufficient power." The APs are connected to an 802. 3at-capable switch.
In this scenario, what would be the cause of the error?

A. The APs' firmware must be upgraded.
B. The cable run to each AP is too long.
C. LLDP-MED is not configured on the switch.
D. The Ethernet cable is plugged into the wrong port on the AP.

正解：C

質問 # 45
What are two characteristics of the 2.4 GHz band when compared to the 5 GHz band? (Choose two.)

A. more congestion
B. lower frequency
C. shorter wavelength
D. less non-Wi-Fi interference

正解：A、B

質問 # 46
Referring to the exhibit, what do you determine about the site's Time to Connect SLE metric?

A. All clients cannot connect to the Internet.
B. Successful connect averaged 1.6 seconds.
C. Time to Connect Association DHCP failures impacted 80% of users.
D. Eighty percent of the Time to Connect failures are related to DHCP failures

正解：D

解説：
The correct answer is B. Eighty percent of the Time to Connect failures are related to DHCP failures. This is what you can determine about the site's Time to Connect SLE metric from the exhibit. The exhibit shows a root cause analysis chart that displays the Service Level Metrics and the Classifiers for the site. The Service Level Metrics section shows the percentage of time to connect, which is the time it takes for a client device to connect to the wireless network. The Classifiers section shows the percentage of authorization, association, internet services, and DHCP, which are the steps involved in the connection process. The blue line connects the two sections and shows the correlation between them.
The exhibit shows that the site has a Time to Connect SLE metric of 20%, which means that only 20% of the client devices were able to connect to the wireless network within the expected time. The exhibit also shows that 80% of the Time to Connect failures are related to DHCP failures, which means that 80% of the client devices were not able to obtain an IP address from the DHCP server. This indicates that there is a problem with the DHCP service or configuration at the site.

質問 # 47
You attempt to log in to manage.mist.com, however you receive a 404 error from your browser. You are able to browse other public websites and you suspect a problem with manage.mist.com.
In this scenario, which step would you take to immediately find out the status of the Mist cloud?

A. Visit https://support.juniper.net/support/.
B. Visit https://status.mist.com.
C. Visit https://mist.com/status.
D. Visit https://www.mist.com/support.

正解：B

解説：
The step that you would take to immediately find out the status of the Mist cloud is to visit https://status.mist.com. This is the official website that provides real-time information and updates on the availability and performance of the Mist cloud services, such as the Mist portal, the Mist API, the Mist AI engine, and the Mist regions. You can also subscribe to receive notifications via email, SMS, or webhook when there are any incidents or maintenance events affecting the Mist cloud.

質問 # 48
Under ideal conditions, which frequency band will have the farthest usable range?

A. 5 GHz
B. 900 MHz
C. 6 GHz
D. 2.4 GHz

正解：B

解説：
Reference:
The correct answer is A. 900 MHz. This is the frequency band that will have the farthest usable range under ideal conditions. The range of a wireless signal depends on several factors, such as the transmit power, the antenna gain, the receiver sensitivity, the propagation environment, and the interference level1. However, in general, lower frequency signals can travel farther than higher frequency signals, as they have less attenuation (signal loss) and can penetrate solid objects better2. The 900 MHz band is a lower frequency band than the 2.4 GHz, 5 GHz, and 6 GHz bands, which are commonly used for Wi-Fi and other wireless technologies3. Therefore, the 900 MHz band will have the farthest usable range under ideal conditions. However, the 900 MHz band also has less bandwidth and speed than the higher frequency bands, as well as more interference from other devices that use the same band3. Therefore, the 900 MHz band may not be suitable for some wireless applications that require high data rates or low latency.

質問 # 49
A Mist mesh network supports up to how many hops?

A. 3 hops
B. 2 hops
C. 1 hop
D. 4 hops

正解：B

解説：
The correct answer is B. 2 hops. A Mist mesh network supports up to two hops between the root AP and the leaf AP1. A mesh network is a wireless network that allows APs to communicate with each other without a wired connection. The root AP is the AP that has a wired connection to the network, and the leaf AP is the AP that connects to the root AP or another leaf AP wirelessly. A hop is the number of wireless links between the root AP and the leaf AP. A Mist mesh network can have up to two hops, meaning that a leaf AP can connect to another leaf AP that is one hop away from the root AP1. This allows for more flexibility and coverage in areas where wired connections are not available or feasible1.
1: Mist Mesh Network

質問 # 50
You are troubleshooting a signal strength issue when you notice that the signal strength changes from -70 to -73 dBm as you move from one room to another.
In this scenario, what is happening?

A. Signal strength has doubled.
B. Signal strength has halved.
C. Signal strength has decreased by 10x.
D. Signal strength has increased by 10x.

正解：C

解説：
According to the Wikipedia article on dBm1, a 10 dB increase in level is equivalent to a ten-fold increase in power, and a 10 dB decrease in level is equivalent to a ten-fold decrease in power. Therefore, a 3 dB change in level is approximately equivalent to doubling or halving the power.
In this scenario, the signal strength has changed from -70 dBm to -73 dBm, which is a 3 dB decrease in level. This means that the signal strength has halved, or decreased by 50%. To calculate the ratio of the signal strengths, we can use the following formula:
fracP1P2=10fracx1x210
where P1 and P2 are the powers in mW, and x1 and x2 are the levels in dBm. Plugging in the values from the scenario, we get:
fracP1P2=10frac-70-(-73)10=10frac310approx1.995
This means that the power at -70 dBm is about 2 times higher than the power at -73 dBm, or equivalently, the power at -73 dBm is about 0.5 times lower than the power at -70 dBm.

質問 # 51
Mist Insights will provide detailed information about which two categories? (Choose two.)

A. Client
B. Templates
C. AP
D. Organization

正解：B、D

質問 # 52
When would be the earliest opportunity to configure an access point (AP)?

A. after the AP is installed
B. after you are on the same network as the AP
C. after the AP is online
D. after the AP is claimed to inventory

正解：A

質問 # 53
When would be the earliest opportunity to configure an access point (AP)?

A. after the AP is installed
B. after you are on the same network as the AP
C. after the AP is online
D. after the AP is claimed to inventory

正解：D

解説：
Reference:
This is the earliest opportunity to configure an access point (AP) in the Juniper Mist cloud. According to the Juniper Mist documentation1, the steps to configure an AP are as follows:
Claim the AP to inventory: This step involves entering the serial number or MAC address of the AP in the Juniper Mist cloud portal, which will add the AP to the inventory and assign it a subscription.
Assign the AP to a site: This step involves selecting a site from the inventory and dragging and dropping the AP to the site. This will apply the site-level settings and policies to the AP.
Configure the AP settings: This step involves editing the AP settings, such as name, location, labels, templates, and radio profiles. This can be done individually or in bulk for multiple APs.

質問 # 54
Which Mist supported API is considered data-driven?

A. Webhook
B. RESTful
C. gRPC
D. WebSocket

正解：C

質問 # 55
In the Mist Access Point portfolio, which dedicated device would be used in location-based services (LBS)?

A. BT11
B. AP32
C. AP12
D. AP34

正解：A

質問 # 56
What happens when Mist subscriptions expire?

A. Devices retain their configurations but Mist management GUI functionality related to expired subscriptions are not configurable by the user.
B. Devices retain their configurations and all Mist management GUI functionality remains available to the user.
C. Devices retain their configurations for 90 days; if the subscriptions are not renewed, the configuration is deleted and the devices are reset to factory default.
D. Devices retain their configurations but the Mist user is prevented from accessing the Mist management GUI.

正解：A

質問 # 57
Which two categories are included in the Connectivity Marvis Action? (Choose two.)

A. ARP Failure
B. Bad Cable
C. Offline AP
D. DNS Failure

正解：C、D

質問 # 58
What is an 802.11 management frame transmitted by an AP?

A. ping
B. echo request
C. keepalive
D. beacon

正解：D

解説：
Reference:
According to the Wikipedia article on 802.11 Frame Types1, a beacon frame is a type of management frame that contains information about the network and is broadcast by the access point (AP) periodically to announce its presence and provide the necessary information for other devices to join the network. A beacon frame includes the following information elements:
Timestamp: a 64-bit value that represents the time when the AP started to transmit the frame.
Beacon Interval: a 16-bit value that indicates the time interval between beacon transmissions, measured in time units (TUs) of 1024 microseconds.
Capability Information: a 16-bit bitmap that specifies the supported features and capabilities of the network, such as encryption, authentication, and power management.
SSID: a variable-length field that contains the name of the network.
Supported Rates: a variable-length field that lists the data rates supported by the network, in units of 500 kbps.
Other optional information elements, such as country code, channel number, HT and VHT operations, RSN settings, and WMM parameters.

質問 # 59
Which two statements about the Mist UI are true? (Choose two.)

A. It can initiate a BLE packet capture.
B. It can initiate a packet capture on cloud uplink.
C. It can initiate a wired packet capture.
D. It can initiate a wireless packet capture.

正解：C、D

解説：
Reference:
According to the official Mist documentation1, wireless packet captures are helpful when trying to dissect and dig down into the root cause of any wireless issue between a client and AP. You can determine if packets being sent are actually reaching their destination as well as identify if packets are corrupted. With the enhanced packet capture flow, Mist also introduced the ability to capture packets on the wired side of your network as well. This data is captured from the Eth0 port of your AP, and will examine the packets between the AP and the rest of your wired network. This includes any RADIUS, DHCP, or DNS servers you have set up.
The Mist UI does not support BLE packet capture or packet capture on cloud uplink.

質問 # 60
You are asked to invite a new user to administer specific sites in read-only mode.
Which two roles are available to the new user? (Choose two.)