The likely cause of the issue of weak Wi-Fi coverage in the office is that the AP is using a directional antenna. A directional antenna is an antenna that radiates or receives radio waves more strongly in one or more directions, creating a focused beam of signal. A directional antenna can provide better coverage and performance for a specific area, but it can also create dead zones or weak spots for other areas. The other options are incorrect because they either do not affect the Wi-Fi coverage or do not match the scenario. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/wlan-rf/rf-fundamentals.htm https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/wlan-rf/antennas.htm

CoS and DSCP are both methods of marking packets for quality of service (QoS) purposes. QoS is a mechanism that allows network devices to prioritize and differentiate traffic based on certain criteria, such as application type, source, destination, etc. CoS stands for Class of Service and is a 3-bit field in the 802.1Q VLAN tag header. CoS can only be used on Ethernet frames that have a VLAN tag, and it can only be preserved within a single VLAN domain. DSCP stands for Differentiated Services Code Point and is a 6-bit field in the IP header. DSCP can be used on any IP packet, regardless of the underlying layer 2 technology, and it can be preserved throughout the IP packet flow, unless it is modified by intermediate devices. References: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos/configuration/15-mt/qos-15-mt-book/qos-overview.html https://www.cisco.com/c/en/us/support/docs/lan-switching/8021q/17056-741-4.html https://www.cisco.com/c/en/us/support/docs/quality-of-service-qos/qos-packet-marking/10103-dscpvalues.html

QoS stands for Quality of Service and is a mechanism that allows network devices to prioritize and differentiate traffic based on certain criteria, such as application type, source, destination, etc 3 .  QoS involves identifying specific traffic for special treatment and applying policies and actions to improve its performance or meet certain service level agreements (SLAs) 3 .  QoS can help network devices to manage congestion, delay, jitter, packet loss, bandwidth allocation, etc., for different types of traffic 3 .  QoS can be implemented at various layers of the network stack and across different network domains. References:  3   https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos/configuration/15-mt/qos-15-mt-book/qos-overview.html

The information that the Inter-Switch Link Protocol configuration uses in the configuration created is B. MAC tables.

The Inter-Switch Link Protocol (ISL) is a protocol that enables the synchronization of data and state information between two VSX peer switches. The ISL uses a version control mechanism and provides backward compatibility regarding VSX synchronization capabilities. The ISL can span long distances (transceiver dependent) and supports different speeds, such as 10G, 25G, 40G, or 100G 1 .

One of the data components that the ISL synchronizes is the MAC table, which is a database that stores the MAC addresses of the devices connected to the switch and the corresponding ports or VLANs. The ISL ensures that both VSX peers have the same MAC table entries and can forward traffic to the correct destination 2 . The ISL also synchronizes other data components, such as ARP table, LACP states for VSX LAGs, and MSTP states 2 .

The Aruba CX 6400 switch is a modular switch that supports high-performance and high-density Ethernet switching for campus and data center networks. One of the features that distinguishes the Aruba CX 6400 switch from most typical campus switches is virtual output queueing (VOQ).  VOQ is a technique that implements large ingress packet buffers on each port to prevent head-of-line blocking and packet loss due to congestion 2 .  VOQ allows each port to have multiple queues for different output ports and prioritize packets based on their destination and QoS class 2 .  VOQ enables the Aruba CX 6400 switch to achieve high throughput and low latency for various traffic types and scenarios. References:  2  https://www.arubanetworks.com/assets/ds/DS_CX6400Series.pdf

The reason is that the linkup delay timer is a feature that delays bringing downstream VSX links up, following a VSX device reboot or an ISL flap. The linkup delay timer has two phases: initial synchronization phase and link-up delay phase.

The initial synchronization phase is the download phase where the rebooted node learns all the LACP+MAC+ARP+STP database entries from its VSX peer through ISLP. The initial synchronization timer, which is not configurable, is the required time to download the database information from the peer.

The link-up delay phase is the duration for installing the downloaded entries to the ASIC, establishing router adjacencies with core nodes and learning upstream routes. The link-up delay timer default value is 180 seconds. Depending on the network size, ARP/rout ing tables size, you might be required to set the timer to a higher value (maximum 600 seconds).

When both VSX devices reboot, the link-up delay timer is not used.

Therefore, by configuring the linkup delay timer to include LAGs 101 and 102, which are part of the same VSX device as LAG 201, you can ensure that both devices have enough time to synchronize their databases and form routing adjacencies before bringing down their downstream links.

Change of Authorization (CoA) is a feature that allows ClearPass Policy Manager (CPPM) to send messages to network devices such as switches to change the authorization state of a user session. CoA requires that both CPPM and the network device support this feature and have it enabled. For AOS-CX switches, CoA must be globally enabled using the command  radius-server coa enable . If CoA is not enabled on the switch, the disconnect CoA message from CPPM will be ignored and the user session will not be terminated. References: https://www.arubanetworks.com/techdocs/ClearPass/6.7/PolicyManager/index.htm#CPPM_UserGuide/Admin/ChangeOfAuthorization.htm https://techhub.hpe.com/eginfolib/Aruba/OS-CX_10.04/5200-6692/GUID-9B8F6E8F-9C7A-4F0D-AE7B-9D8E6C5B6A7F.html

These are the correct requirements to ensure that WMM (Wi-Fi Multimedia) is working effectively. WMM is a standard that provides quality of service (QoS) for wireless networks by prioritizing traffic into four categories: voice, video, best effort, and background. To use WMM, both the APs and the controller must be Wi-Fi CERTIFIED for WMM, which means they have passed interoperability tests and comply with the standard. WMM must also be enabled on the APs and the controller, which is usually the default setting. The client device must also be Wi-Fi CERTIFIED for WMM and configured for WMM marking, which means it can tag its traffic with the appropriate priority level based on the application type. The other options are incorrect because they are either not related to WMM or not required for WMM to work. References: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/wlan-qos/wmm.htm https://www.wi-fi.org/discover-wi-fi/wi-fi-certified-wmm