HP HPE7-A08 Practice Test Questions Answers

To protect a network from Layer 2 man-in-the-middle attacks, AOS-CX switches utilize two closely related security features: DHCP Snooping and Dynamic ARP Protection .

DHCP Snooping: This feature acts as a firewall between untrusted hosts and trusted DHCP servers. When enabled, the switch categorizes ports as either trusted (connected to a legitimate DHCP server or another switch) or untrusted (connected to end-user devices). If a " malicious " DHCP server on an untrusted port attempts to send a DHCP OFFER or ACK message, the switch drops the packet.

The Snooping Binding Table: As a byproduct of monitoring legitimate DHCP exchanges, the switch builds a DHCP Snooping Binding Table . This table is a " source of truth " that maps a client ' s MAC address to its assigned IP address and the specific physical port it is connected to.

Dynamic ARP Protection: ARP poisoning (or spoofing) occurs when an attacker sends fake ARP messages to link their MAC address with the IP address of a legitimate server or gateway. When ARP protection is enabled, the switch intercepts all ARP packets on untrusted ports and validates them against the DHCP Snooping Binding Table . If the MAC-to-IP mapping in the ARP packet does not match the entry in the table, the packet is discarded.

Integration: These two features must work together. Without the binding table created by DHCP Snooping, ARP Protection has no data to validate against. This combination ensures that only the device that legitimately received an IP via DHCP can claim that IP in ARP responses.

In network environments where users might connect unauthorized, " dumb " (unmanaged) switches or hubs, standard Spanning Tree Protocol (STP) may not be sufficient to prevent loops.

The Limitation of STP and BPDU Guard: BPDU Guard is an excellent feature that disables a port if it receives a Bridge Protocol Data Unit (BPDU). However, many unmanaged switches do not participate in STP and therefore do not originate BPDUs. Some may simply forward BPDUs or drop them entirely. If a loop is created through an unmanaged switch that doesn ' t send BPDUs, BPDU Guard will never trigger.

How Loop Protection Works: AOS-CX Loop Protection is specifically designed for this scenario. The switch sends out proprietary Loop Protection packets at a configured interval. If the switch receives its own Loop Protection packet back on the same port (or a different port in the same VLAN), it knows a loop exists.

Action on Detection: Upon detecting the loop, the switch can be configured to send an SNMP trap and, more importantly, disable the port to stop the broadcast storm and prevent a network outage.

Best Practice: Loop protection is commonly recommended for " Access " or " Colorless " ports where end-user devices connect, as it provides a safety net against loops caused by non-STP aware devices.

This exhibit displays the Configuration Status dashboard within HPE Aruba Networking Central for a specific switch (SW0).

Interpreting " Local Overrides " : In the Central management model, switches are typically assigned to a Group , and they inherit the configuration of that group (the " inherited settings " ). A Local Override (as explicitly defined in the exhibit ' s header text) occurs when an administrator makes a configuration change at the individual device level within Central. This device-specific configuration takes precedence over the group-level settings.

Analysis of SW0:

The table shows Local Overrides: Yes . This confirms that SW0 has unique configuration parameters applied to it that differ from the baseline configuration of its assigned group.

The Config Status is Synchronized , meaning these device-level changes have already been successfully pushed to the switch.

Evaluating the Options:

Option B (Correct): Having a " Local Override " means that a configuration has been pushed to the switch which deviates from the " default " (inherited group) settings.

Option A: " Local Overrides " in Central refers to the Central UI device-level settings , not changes made directly on the local physical CLI of the switch.

Option C: While Central does track configuration health, this specific screen is showing override and commit status, not the detailed logic for auto-checkpoints.

Option D: The exhibit shows Auto-commit Changes State: ON . This means any change made in Central is automatically committed and pushed to the device; no manual commit action is required by the administrator.