Juniper JN0-251 Exam

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.

According to the Cisco Content Hub1, Wi-Fi is half duplex, meaning we can either transmit (Tx) or receive (Rx) on the medium, the clients and the network take turns accessing the medium. Wi-Fi is contention based, meaning there are rules for stations trying to access the medium and collisions (due to two or more stations simultaneously accessing the medium) are worked out fairly so everyone gets a chance.

According to the web search results, the Mist Location Engine is a service that provides location-based services (LBS) for wireless networks, such as indoor positioning, wayfinding, or asset tracking1.The Mist Location Engine uses a patented dynamic BLE array that consists of 16 directional antennas that transmit BLE signals in eight different directions2.The user device, such as a smartphone or a tablet, can receive these signals and send the signal information, such as the RSSI and the device sensor data, back to the Mist Location Engine via Wi-Fi or cellular2.

The Mist Location Engine then processes the signal information and uses machine learning and probability surfaces to determine the location of the user device2.The location is expressed as an x,y coordinate on a floor plan map that represents the highest probability of where the user device is located2.The Mist Location Engine can also provide other information, such as the location accuracy, the location history, and the location events of the user device2.

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=10frac70(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.

According to the web search results, TCP/443 is the port that must be allowed on your company's firewall for AP access to the Mist cloud.TCP/443 is the port that is used for HTTPS, which is a secure version of HTTP that encrypts the data sent between the client and the server1.Mist APs use HTTPS to communicate with the Mist cloud and receive their configuration, firmware, and policies2.TCP/443 is also the port that is used for ep-terminator, which is a service that provides encrypted tunneling between Mist APs and the Mist cloud3. Therefore, TCP/443 is the port that must be allowed on your company's firewall for AP access to the Mist cloud.