Pass HPE7-A02 Exam Guide

To minimize disruption time if an AOS-CX switch reboots while implementing DHCP snooping and ARP inspection, you should save the IP-to-MAC bindings to external storage. This ensures that the DHCP snooping and ARP inspection tables, which are crucial for preventing spoofing attacks, are preserved across reboots. When the switch restarts, it can reload these bindings from the external storage, thereby maintaining network security and reducing the downtime associated with rebuilding these tables.

1.Preserving Bindings: Saving IP-to-MAC bindings to external storage ensures that these critical security tables are not lost during a reboot, maintaining network integrity.

2.Security Continuity: This practice helps to quickly restore security features like DHCP snooping and ARP inspection, minimizing the window of vulnerability.

3.Operational Efficiency: By preserving these bindings, the switch can resume normal operations faster, reducing disruption to network services.

The "Detect Valid SSID Misuse" event in Aruba's Wireless Intrusion Detection System (WIDS) indicates that a valid SSID, associated with your network, is being broadcast from an unauthorized source. This scenario often signals a potential rogue access point attempting to deceive clients into connecting to it (e.g., for credential harvesting or man-in-the-middle attacks).

1. Explanation of Each Option

A. Clients are failing to authenticate to corporate SSIDs. You should first check for misconfigured authentication settings and then investigate a possible threat:

Incorrect:

This event is not related to authentication failures by legitimate clients.

Misconfigured authentication settings would lead to events like "authentication failures" or "radius issues," not "valid SSID misuse."

B. Admins have likely misconfigured SSID security settings on some of the company's APs. You should have them check those settings:

Incorrect:

This event refers to an external device broadcasting your SSID, not misconfiguration on the company’s authorized APs.

WIDS differentiates between valid corporate APs and rogue APs.

C. Hackers are likely trying to pose as authorized APs. You should use the detecting radio information and immediately track down the device that triggered the event:

Correct:

This is the most likely cause of the "detect valid SSID misuse" event. A rogue AP broadcasting a corporate SSID could lure clients into connecting to it, exposing sensitive credentials or traffic.

Immediate action includes:

Using the radio information from the event logs to identify the rogue AP's location.

Physically locating and removing the rogue device.

Strengthening WIPS/WIDS policies to prevent further misuse.

D. This event might be a threat but is almost always a false positive. You should wait to see the event over several days before following up on it:

Incorrect:

While false positives are possible, "valid SSID misuse" is a critical security event that should not be ignored.

Delaying action increases the risk of successful attacks against your network.

2. Recommended Steps to Address the Event

Review Event Logs:

Gather details about the rogue AP, such as SSID, MAC address, channel, and signal strength.

Locate the Rogue Device:

Use the detecting AP's radio information and signal strength to triangulate the rogue AP's physical location.

Respond to the Threat:

Remove or disable the rogue device.

Notify the security team for further investigation.

Prevent Future Misuse:

Strengthen security policies, such as enabling client whitelists or enhancing WIPS protection.

References

Aruba WIDS/WIPS Configuration and Best Practices Guide.

Aruba Central Security Event Analysis Documentation.

Wireless Threat Management Using Aruba Networks.

Running periodic subnet scans on devices from HPE Aruba Networking ClearPass Policy Manager (CPPM) can be used to gather DHCP fingerprints, which help determine a client's device category and operating system. DHCP fingerprints are unique patterns in DHCP request packets that provide valuable information about the device type and OS, assisting in device profiling and policy enforcement.

1.DHCP Fingerprinting: This technique captures specific details from DHCP packets to identify the type and operating system of a device.

2.Device Profiling: By running subnet scans, CPPM can continuously update its device database with accurate profiles, ensuring that policies are applied correctly based on the device type.

3.Network Visibility: Regular scanning helps maintain up-to-date visibility of all devices on the network, improving security and management.

The preferred method for assigning clients to a role on the AOS firewall is to configure HPE Aruba Networking ClearPass Policy Manager (CPPM) to assign the role using a RADIUS enforcement profile with an Aruba-User-Role VSA (Vendor-Specific Attribute). This method allows ClearPass to dynamically assign the appropriate user roles to clients during the authentication process, ensuring that role-based access policies are consistently enforced across the network.