Pass the HP ACA - Network Security HPE6-A84 Questions and answers with CertsForce

This is because ARP inspection is a security feature that validates ARP packets in a network and prevents ARP poisoning attacks12 ARP inspection works by intercepting, logging, and discarding ARP packets with invalid IP-to-MAC address bindings1 To enable ARP inspection, the switch needs to know which ports are trusted and which are untrusted. Trusted ports are those that connect to authorized DHCP servers or other network devices that are not vulnerable to ARP spoofing. Untrusted ports are those that connect to end hosts or devices that might send forged ARP packets13

In the exhibit, LAG 1 is configured as a trusted port for ARP inspection, which is correct because it connects to the core switch. However, the edge ports (1/1/1-1/1/24) are not configured as untrusted ports for ARP inspection, which is incorrect because they connect to end hosts that might be compromised by an attacker. By default, all ports are untrusted for ARP inspection, but this can be changed by using the command ip arp inspection trust on the interface configuration mode3 Therefore, to protect VLAN 4 against ARP poisoning, the edge ports should be configured as untrusted for ARP inspection by using the command no ip arp inspection trust on the interface configuration mode. This way, the switch will validate the ARP packets received on these ports against the DHCP snooping database or an ARP access-list and drop any invalid packets34

A. ARP proxy is not enabled on VLAN 4. This is not an issue because ARP proxy is an optional feature that allows the switch to respond to ARP requests on behalf of hosts in different subnets5 It is not related to ARP poisoning or ARP inspection.

B. LAG 1 is configured as trusted for ARP inspection but should be untrusted. This is not an issue because LAG 1 connects to the core switch, which is a trusted device that does not send forged ARP packets.

C. DHCP snooping is not enabled on VLAN 4. This is not an issue because DHCP snooping is a separate feature that prevents rogue DHCP servers from offering IP addresses to clients6 It is not directly related to ARP poisoning or ARP inspection, although it can provide information for ARP inspection validation if enabled

The VIA web authentication profile is used to authenticate the users who want to download the VIA connection settings from the VPNCs. The VPNCs can use either an internal database or an external server (such as RADIUS or LDAP) as the authentication source for this profile. To ensure that only authorized users obtain VIA connection settings, you should use CPPM as the external server and configure a service on CPPM that uses AD as the authentication source. This way, you can leverage the role mapping and enforcement features of CPPM to check if the users belong to the “RemoteEmployees” AD group and grant or deny them access accordingly1

The other options are not correct because they do not allow you to verify the users’ AD group membership before providing them with VIA connection settings. Option B would only check the users’ credentials against AD, but not their group membership. Option C would only apply to the VPN connection phase, not the VIA connection settings phase. Option D would not work because the VPNCs do not support LDAP as an authentication source for VIA connection profiles2

This option allows CPPM to receive real-time information about the network activity and security posture of the clients from the firewall, and then apply appropriate enforcement actions based on the configured policies 12. For example, if a client is detected to be infected with malware or violating the network usage policy, CPPM can quarantine or disconnect the client from the network 2.

According to the Aruba Cloud Authentication and Policy Overview1, Device Insight tags are stored in the Endpoint Repository and can be used as conditions within CPPM role mapping or enforcement policy rules. The rule condition type should be Endpoint, and the attribute should be Device Insight Tags. No extra authorization source is required for services that use policies with these rules. Therefore, option D is the correct answer.

Option A is incorrect because creating an HTTP authentication source to the Central API is not necessary to use Device Insight tags as conditions. Device Insight tags are already synchronized between Central and CPPM, and can be accessed from the Endpoint Repository.

Option B is incorrect because using the Application type for the rule conditions is not applicable to Device Insight tags. The Application type is used to match attributes from the Application Authentication source, which is used to integrate with third-party applications such as Microsoft Intune or Google G Suite.

Option C is incorrect because using the Endpoints Repository type for the rule conditions is not valid for Device Insight tags. The Endpoints Repository type is used to match attributes from the Endpoints Repository source, which is different from the Endpoint type. The Endpoints Repository source contains information about endpoints that are manually added or imported into CPPM, while the Endpoint type contains information about endpoints that are dynamically discovered and profiled by CPPM or Device Insight. Adding Endpoints Repository as a secondary authentication source for services that use policies with these rules is also unnecessary and redundant.

A DNS SAN (Subject Alternative Name) is an extension of the X.509 certificate standard that allows specifying additional hostnames or IP addresses that the certificate can be used for. A DNS SAN is useful for validating the identity of the server or client that presents the certificate, especially when the common name (CN) field does not match the hostname or IP address of the server or client.

In this case, the certificate has a CN of mc41.site94.example.com, which is the fully qualified domain name (FQDN) of the standalone Aruba Mobility Controller (MC). However, this CN may not match the hostname or IP address that the MC uses for the Web UI or for implementing RadSec with Aruba ClearPass Policy Manager. For example, if the MC uses a different FQDN, such as mc41.example.com, or an IP address, such as 192.168.1.41, for these purposes, then the certificate would not be valid for them. Therefore, the certificate should have a DNS SAN that includes all the possible hostnames or IP addresses that the MC may use for the Web UI and RadSec.

The exhibit shows the ArubaOS-CX REST API documentation interface, which allows you to explore the available resources and try out the API calls using the “Try it out” button. However, before you can use this feature, you need to authenticate yourself with your Aruba passport account and collect a token that will be used for subsequent requests. This token will expire after a certain time, so you need to refresh it periodically. You can find more details about how to use the documentation interface and collect a token in the ArubaOS-CX REST API Guide1.

The correct answer is B. Create a new VLAN on the AOS-CX switch and configure that VLAN as the UBT client VLAN.

User-based tunneling (UBT) is a feature that allows the AOS-CX switches to tunnel the traffic from wired clients to a mobility gateway cluster, where they can be assigned a role and a VLAN based on their authentication and authorization 1. To enable UBT, the switches need to have a UBT zone configured with the IP addresses of the gateways, and a UBT client VLAN configured with the ubt-client-vlan command 2.

The UBT client VLAN is a special VLAN that is used to encapsulate the traffic from the tunneled clients before sending it to the gateways. The UBT client VLAN must be different from any other VLANs used on the switch or the network, and it must not be assigned to any ports or interfaces on the switch 2. The UBT client VLAN is only used internally by the switch for UBT, and it is not visible to the clients or the gateways.

In this scenario, the customer wants to tunnel the clients that pass user authentication to the gateway cluster, where they will be assigned to VLAN 20. Therefore, the switch must have a UBT client VLAN configured that is different from VLAN 20 or any other VLANs on the network. For example, the switch can use VLAN 4000 as the UBT client VLAN, as shown in one of the web search results 3. The switch must also have a UBT zone configured with the system IP addresses of the gateways as the primary and backup controllers, as explained in question 3.

The other options are not correct or relevant for this issue:

Option A is not correct because assigning VLAN 20 as the access VLAN on any edge ports to which tunneled clients might connect would conflict with UBT. The access VLAN is the VLAN that is assigned to untagged traffic on a port, and it is used for local switching on the switch 4. If VLAN 20 is assigned as the access VLAN, then the traffic from the clients will not be tunneled to the gateways, but rather switched locally on VLAN 20. This would defeat the purpose of UBT and cause inconsistency in role and VLAN assignment.

Option C is not correct because VIA licenses are not required for UBT. VIA licenses are required for enabling VPN services on Aruba Mobility Controllers for remote access clients using Aruba Virtual Intranet Access (VIA) software . VIA licenses are not related to UBT or wired clients.

Option D is not correct because changing the port-access auth-mode mode to client-mode on any edge ports to which tunneled clients might connect would not affect UBT. The port-access auth-mode mode determines how a port handles authentication requests from multiple clients connected to a single port . Client-mode is the default mode that allows only one client per port, while multi-client-mode allows multiple clients per port. The port-access auth-mode mode does not affect how UBT works or how traffic is tunneled from a port.

MPSK (Multi Pre-Shared Key) is a feature that allows assigning different pre-shared keys (PSKs) to different devices or groups of devices on the same WLAN. MPSK improves security over WPA2 in personal mode, which uses a single PSK for all devices on the WLAN. With MPSK, you can create and manage multiple PSKs, each with its own role, policy, and expiration date. You can also revoke or change a PSK for a specific device or group without affecting other devices on the WLAN. MPSK is compatible with devices that support WPA2 in personal mode only, as they do not need to support any additional protocols or certificates.

To use MPSK on the WLAN to which the devices connect, you need to enable MPSK in the WLAN settings and configure the PSKs in Aruba ClearPass Policy Manager (CPPM). You can find more information about how to configure MPSK in the [Configuring Multi Pre-Shared Key - Aruba] page and the [ClearPass Policy Manager User Guide] . The other options are not correct because they either do not improve security or are not applicable for devices that support WPA2 in personal mode only. For example, configuring WIDS policies that apply extra monitoring to these particular devices would not prevent them from being compromised or spoofed, but rather detect and mitigate potential attacks. Connecting these devices to the same WLAN to which 802.1X-capable clients connect, using MAC-Auth fallback, would not provide strong authentication or encryption, as MAC addresses can be easily spoofed or captured. Enabling dynamic authorization (RFC 3576) in the AAA profile for the devices would not affect the authentication process, but rather allow CPPM to change the attributes or status of a user session on the controller without requiring re-authentication.

MAC Authentication Bypass (MAB) is a technique that allows non-802.1X-capable devices to bypass the 802.1X authentication process and gain network access based on their MAC addresses. However, MAB has some security drawbacks, such as the possibility of MAC address spoofing or unauthorized devices being added to the network. Therefore, it is recommended to use a custom MAC-Auth authentication method that adds an additional layer of security to MAB.

A custom MAC-Auth authentication method is a method that uses a combination of the MAC address and another attribute, such as a username, password, or certificate, to authenticate the device. This way, the device needs to provide both the MAC address and the additional attribute to gain access, making it harder for an attacker to spoof or impersonate the device. A custom MAC-Auth authentication method can be created and configured in ClearPass Policy Manager (CPPM) by following the steps in the Customizing MAC Authentication - Aruba page.