Bonding multiple 20MHz wide 802.11 channels is a technique to create a wider bandwidth channel that supports higher data rate transmissions. It can increase the throughput between the client and AP by using more spectrum resources and reducing interference. Reference: https://ieeexplore.ieee.org/document/9288995 Bonding multiple 20MHz wide 802.11 channels is a technique used to increase the throughput between the client device and the Access Point (AP). By combining two or more 20MHz channels into a wider channel (e.g., 40MHz, 80MHz, or even 160MHz), the data carrying capacity and, consequently, the overall throughput of the wireless connection are increased. This method is particularly useful in high-bandwidth applications or environments where higher data rates are required.

Explanation
Virtual Switching Extension (VSX) is a feature that allows two Aruba CX switches to operate as a single logical device with a single control plane and data plane. VSX provides high availability, scalability, and simplified management for campus and data center networks3. In VSX, one switch is designated as the primary switch and the other as the secondary switch. The primary switch owns and responds to ARP Address Resolution Protocol. ARP is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. requests for the virtual IP address of the VSX pair4. The virtual IP address is used as the default gateway for clients connected to the access switch. If the primary switch fails, the secondary switch takes over the virtual IP address and continues to forward traffic for the clients5.
References: 3
https://www.arubanetworks.com/techdocs/AOS-CX_10_04/UG/Content/cx-ug/vsx/vsx-overview.htm 4
https://www.arubanetworks.com/techdocs/AOS-CX_10_04/UG/Content/cx-ug/vsx/vsx-ip-addressing.htm 5
https://www.arubanetworks.com/techdocs/AOS-CX_10_04/UG/Content/cx-ug/vsx/vsx-failover.htm

Explanation
Aruba Central allows you to create device configuration groups that define common settings for devices within each group. You can create different types of groupsdepending on your network requirements and management preferences. Two types of groups that you can define in Aruba Central during group creation are:
Template group: A template group allows you to create configuration templates using variables and expressions that can be applied to multiple devices or device groups. Template groups provide flexibility and scalability for managing large-scale deployments with similar configurations.
Default group: A default group is automatically created when you add devices to Aruba Central for the first time. The default group contains basic configuration settings that are applied to all devices that are not assigned to any other group. You can modify or delete the default group as needed.
References: https://www.arubanetworks.com/techdocs/Central/latest/content/nms/device-groups.htm
https://www.arubanetworks.com/techdocs/Central/latest/content/nms/template-groups.htm
https://www.arubanetworks.com/techdocs/Central/latest/content/nms/default-group.htm

Explanation
The signal to noise ratio (SNR) is a measure that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels (dB). A high SNR means that the signal is clear and easy to detect or interpret, while a low SNR means that the signal is corrupted or obscured by noise and may be difficult to distinguish or recover3. To calculate the SNR in dB, we can use the following formula:
SNR (dB) = Signal power (dBm) - Noise power (dBm)
In this question, we are given that the noise floor measures -90 dBm (0.000000001 milliwatts) and the receiver's signal strength is -65 dBm (0.000316 milliwatts). Therefore, we can plug these values into the formula and get:
SNR (dB) = -65 dBm - (-90 dBm) SNR (dB) = -65 dBm + 90 dBm SNR (dB) = 25 dBm Therefore, the correct answer is that the SNR is 25 dBm.
References: 3 https://en.wikipedia.org/wiki/Signal-to-noise_ratio

For "headless" devices that lack 802.1X support, Multi-Preshared Keys (mPSK) provide a more secure alternative to WPA2-Personal, which uses a single preshared key. mPSK allows for the assignment of unique PSKs to devices or groups of devices, which enhances security by not sharing a single PSK across multiple devices.