HP Updated HPE7-A08 Exam Questions and Answers by zorawar

To isolate wired ports on the same VLAN on a large scale (such as hotel rooms) but allow communication within the same VLAN for common areas, Private VLANs (PVLANs) are recommended. PVLANs allow segmentation within a single VLAN by dividing it into primary and secondary VLANs, controlling communication between ports.

VPN and VXLAN are overlay technologies for different purposes.

UBT (User-Based Tunneling) is related to wireless user segmentation, not wired port isolation.

Therefore, PVLANs provide the simplest and most effective solution to isolate room ports within a single VLAN.

The customer wants to tunnel traffic from APs through CX switches, similar to what they currently do with a gateway cluster. Aruba’s User-Based Tunneling (UBT) is designed specifically for this use case. UBT allows traffic from wireless and wired clients to be tunneled to a centralized gateway or controller for policy enforcement and traffic inspection.

IPSec and GRE are general tunneling protocols but not Aruba’s recommended solution for AP traffic.

VNBT relates to colorless ports and dynamic segmentation, not tunneling client traffic.

Thus, UBT is the correct tunneling solution for AP traffic through CX switches.

To prevent rogue DHCP servers in a VLAN, DHCP snooping authorized-server commands are used to specify trusted DHCP servers allowed to respond.

Option A (dhcpv4-snooping trust 10.100.100.10) configures a trusted port, but it is not VLAN specific and not precise enough for this purpose.

Enabling DHCP snooping globally and on VLAN or interface (Options C and D) are prerequisites but do not prevent rogue servers unless authorized servers are defined.

Option B correctly enables an authorized DHCP server IP on VLAN 30, blocking unauthorized DHCP responses.

To resolve this QoS mapping issue on AOS-CX, you must understand the hierarchy of Trust Levels and how they interact with Link Aggregation Groups (LAGs).

Trust Hierarchy: AOS-CX switches use a " top-down " approach for QoS.

Global Trust: Setting qos trust dscp globally means that, by default, every port on the switch will look at the Layer 3 DSCP markings to determine queue priority.

Interface Override: You can override the global setting on a per-interface basis. If a specific device or service (like the video streaming service in this prompt) relies solely on Layer 2 CoS (802.1p) markings rather than DSCP, the switch will ignore those CoS markings under the global DSCP policy and place the traffic in a default (best-effort) queue.

LAG Configuration Logic: In the AOS-CX architecture, a LAG is a logical interface (interface lag 20).

Configuration parameters for the bundle (such as VLANs, ACLs, and QoS trust) should be applied to the logical LAG interface, not the individual physical member ports (1/1/20 and 2/1/20).

Once applied to the LAG, the settings are automatically inherited by all physical members.

Analyzing the Options:

Option D (Correct): By entering the interface lag 20 context and applying qos trust cos, you are instructing the switch to ignore the global DSCP setting for this specific bundle and instead trust the Layer 2 priority bits. This allows the video service to once again map correctly to the intended priority queues.

Option A: This is unnecessarily complex. Setting the physical member ports to qos trust none and then the LAG to cos is redundant because the LAG configuration overrides the physical port settings in this context.

Option B: qos trust dscp, cos is not a valid AOS-CX command. Unlike the older AOS-S (ProCurve) software which allowed a combined dscp-cos trust, AOS-CX requires you to choose a single trust type (DSCP, CoS, or None) per interface.

Option C: This applies the configuration to the physical ports only. In an AOS-CX VSF/LAG environment, this is considered a configuration error or " best practice " violation, as the logical LAG interface should hold the configuration.