HP HPE7-A08 Practice Exam Questions & Answers

Explanation

Comprehensive Detailed Explanation:

To prevent man-in-the-middle attacks based on Layer 2 (Ethernet) addressing, enabling ARP inspection in the VLAN context is recommended. ARP inspection validates ARP packets and ensures only legitimate ARP responses are forwarded.

Enabling ARP inspection at VLAN level allows granular control.

Interface-level or global context is less typical or supported for ARP inspection on Aruba CX switches.

ArubaOS-CX Security Features Guide

HPE Aruba ARP Inspection Best Practices

Network Security Documentation for Aruba CX Switches

Explanation

To find which changes were made on an HPE Aruba CX switch from the GUI, the correct command is:

show checkpoint diff --- this compares the running configuration with stored saved-config revisions.

Using 'saved-config revisions' as the comparison base allows the GUI to show what has changed since the last saved configuration.

Other options mix checkpoint and saved-config terminology incorrectly.

ArubaOS-CX Checkpoint and Configuration Revision Guide

HPE Aruba CLI User Guide

Aruba CX Configuration Management Best Practices

Explanation DUR (Downloadable User Roles) requires ClearPass to return role information via RADIUS attributes. For this to work, ClearPass must authenticate with HPE Aruba Networking Central using the correct CPPM username and password in the authentication server configuration. Without these credentials, ClearPass cannot communicate properly to download user roles. LUR works because it doesn't require this external communication, but DUR does.

Explanation When using EAP-TLS, the authentication server (ClearPass) needs to validate the client certificate presented during the TLS handshake. If ClearPass is not configured to trust the client's certificate authority or the certificate itself, the authentication fails at the certificate validation stage. Configuring ClearPass to trust the client certificate allows it to properly verify and accept the client's credentials during the authentication exchange.

Explanation EAP-TLS exchanges full certificate chains which can be quite large, especially if multiple intermediate CAs are involved. If the path MTU between the access point and ClearPass is too small, the RADIUS packets containing these certificates get fragmented or dropped, causing authentication failures. The logs and packet capture would show truncated frames or incomplete RADIUS exchanges. Increasing the MTU along the path allows the full certificate chain to pass through without issues.

Explanation

If both switches are configured with default spanning-tree priorities and both appear as primary root bridges, to have a single spanning tree domain, matching MST configuration (Multiple Spanning Tree) must be created on Core-2 to align with Core-1.

Setting priority to 1 on one switch can help but matching MST configurations is the recommended approach for multiple VLANs.

Creating MST instances on only one switch will not ensure consistency.

Matching MST configurations ensures consistent root bridge election and stable spanning tree.

Aruba MSTP Configuration Guide

IEEE 802.1s Multiple Spanning Tree Protocol

HPE Aruba Network Design Best Practices

Explanation

To enable Layer 3 multicast functionality on an AOS-CX switch, it is essential to understand the roles of different protocols and where they are applied in the hierarchy of the switch configuration.

L3 vs. L2 Multicast:

IGMP (Internet Group Management Protocol): This is a Layer 3 protocol used by hosts to report their multicast group memberships to adjacent routers. It is configured on a Layer 3 interface, such as an SVI (Switch Virtual Interface) or a routed port.

IGMP Snooping: This is a Layer 2 optimization feature. It allows a switch to 'listen in' on IGMP conversations between hosts and routers to constrain multicast traffic to only those ports that have requested it, preventing the traffic from flooding the entire VLAN.

Enabling L3 Multicast Locally: When the 'core switch' acts as the default gateway for multicast receivers, it must be able to process membership reports from those receivers. By enabling IGMP on the SVI (e.g., interface vlan 100), the switch begins listening for IGMP Join/Leave messages from clients on that subnet. This is a prerequisite for the switch to populate its multicast routing table and, when combined with a routing protocol like PIM (Protocol Independent Multicast), forward traffic from a source to those local receivers.

Analysis of Options:

Option A (Correct): IGMP must be enabled on the SVI so the switch can function as a multicast-aware gateway for that specific subnet.

Option B: In AOS-CX syntax, you do not configure 'IGMP' under the L2 vlan [ID] context; it is an L3 function.

Option C: Enabling IGMP-snooping on a VLAN only manages the L2 delivery of traffic; it does not enable L3 routing or the processing of multicast packets across different subnets.

Option D: While IGMP-snooping is often used in conjunction with L3 multicast, it is technically a VLAN-level configuration, not a property of the SVI itself.

Key CLI Commands:

To fully enable this, a professional would typically use:

Bash

router multicast

routing

!

interface vlan 100

ip igmp

ip pim-sm