LACP (Link Aggregation Control Protocol) modes can be active or passive. When two switches are both configured in passive mode, no LACP packets are initiated, causing the link aggregation to fail or go into a block state.

Changing one side from passive to active causes that switch to initiate LACP negotiation, resolving the block state.

Changing to static mode disables LACP negotiation, which is not recommended unless both sides are static.

Changing timeout does not solve LACP block issues caused by mode mismatches.

Therefore, changing one switch’s LACP mode from passive to active is necessary to resolve the block.

The Audit Trail in HPE Aruba Networking Central serves as the primary ledger for compliance and accountability across the entire managed estate.

Accountability (The " Who " ): The fundamental purpose of an audit trail is to provide a record of " who, what, and when. " When a configuration is modified—whether it’s a VLAN change, a port shutdown, or a global routing update—the Audit Trail logs the Username of the administrator or the API key identity that initiated the task.

Validating Changes: In the Global view, the Audit Trail allows a Lead Engineer to verify that changes were authorized. If a network outage occurs, the trail is used to correlate the timing of the outage with the specific user who pushed the last set of changes.

Evaluating Other Options:

Option A: Central typically retains Audit Trail data for up to 90 days (standard) or longer with specific data retention subscriptions, but 7 years is not the standard architectural default for these logs.

Option B: While you can see that a " Config Push " occurred, the detailed Configuration Difference (the " Diff " ) is usually viewed in the Configuration Status or Audit Event Details page, rather than being the primary defining attribute of the basic Audit Trail list.

Option C: The Audit Trail identifies the action (e.g., " Update Switch Configuration " ), but it doesn ' t always distinguish the specific UI workflow (like Multi-edit vs. Standard GUI) used within the Central platform.

Key Exam Tip: Whenever you see " Audit Trail " in an Aruba exam, think Accountability. It is the tool used to track administrator actions.

In a high-security " Colorless Ports " environment using AOS-CX, we often run both 802.1X (Dot1x) and MAC Authentication (MAC-auth) on the same port to handle a mix of corporate laptops and " dumb " IoT devices (printers, cameras).

The Default Behavior: By default, the switch usually attempts 802.1X first. When a device like a printer is plugged in, it does not have an 802.1X " supplicant " to respond to the switch ' s EAPOL-Request packets. The switch will wait for a series of timeouts and retries (EAPOL timeouts) before it gives up on 802.1X and moves on to the next method (MAC-auth). This waiting period is what causes the " few minutes " delay the user is experiencing.

Auth-Precedence vs. Auth-Priority:

Auth-Precedence: This defines the order in which the switch attempts the authentication methods.

Auth-Priority: This defines which method " wins " if multiple methods succeed (relevant for a PC that might trigger both).

The Solution: By changing the auth-precedence to mac-auth dot1x, the switch immediately captures the device ' s MAC address and sends it to the RADIUS server (like Aruba ClearPass) for authentication.

For a printer, MAC-auth succeeds immediately, and the port is authorized without waiting for 802.1X timeouts.

For a corporate laptop, MAC-auth happens first (granting basic or initial access), and then the 802.1X process can trigger immediately after to provide higher-level " User " access.

Why other options are incorrect:

Option A: Disabling 802.1X removes the security for corporate devices on those ports; it is not a " secure configuration " maintenance.

Option B: Increasing the timeout would make the delay worse, not better.

Option D: There is no specific " MAC auth start value " timer in AOS-CX that would solve a multi-minute delay caused by the 802.1X failure wait.

CLI Example:

Bash

interface 1/1/1

aaa authentication port-access auth-precedence mac-auth dot1x

The key evidence is the Actor State for the local lag253(mc) interface. Its state is shown as:

ASFNCD

According to the AOS-CX show lacp interfaces state abbreviations, A means Active, S means Short-timeout , F means Aggregable, N means InSync, C means Collecting, and D means Distributing. Aruba Networks

The significant difference is the S (Short-timeout) state. Other local LAGs in the exhibit show ALFNCD, where L means Long-timeout . AOS-CX uses the slow LACP rate by default , which requests LACP heartbeat transmission every 30 seconds with a 90-second timeout. Configuring lacp rate fast changes this behavior to approximately one-second LACP heartbeats and a three-second timeout. Therefore, the S state on local lag253 demonstrates that this LAG has been explicitly configured away from the default behavior—hence it has a custom LACP rate configuration . Aruba Networks

Option B is not supported by the operational state. Although the partner displays an aggregator key of 0, lag253 is InSync, Collecting, and Distributing , and its forwarding state is up . Thus, the output does not indicate that a different partner aggregator key is required. lag27 likewise shows normal aggregation with both members using the same aggregation key.

Study Guide References: LACP State Flags; show lacp interfaces; LACP Fast/Slow Rate; Short and Long Timeout; VSX Multi-Chassis LAG.

In VSX architecture, the Inter-Switch Link (ISL) is implemented as a Link Aggregation Group (LAG). To ensure proper forwarding and VLAN consistency, the ISL LAG must allow all configured VLANs. This allows VSX synchronization and data forwarding across all VLANs that span the two switches.

ISL traffic is not specifically tagged with EF QoS markings by default.

ISL traffic is not encapsulated in GRE tunnels.

The ISL LAG does not automatically include all VLANs; VLANs must be allowed on the LAG explicitly.

Hence, the LAG must be configured to allow all VLANs.

The Inter-Switch Link Protocol (ISLP) is the proprietary VSX control-plane mechanism used across the VSX Inter-Switch Link to synchronize operational state between the two VSX peers. HPE Aruba Networking specifically documents that each VSX node performs periodic synchronization every second through ISLP , including learned MAC addresses, LACP states , and spanning-tree state information. Therefore, option D directly describes a documented ISLP function. Aruba Networks

LACP synchronization is particularly important for VSX LAGs . Both VSX peers must maintain coordinated LACP state so that a downstream device sees the two physical switches as a consistent multichassis aggregation endpoint. During VSX recovery, ISLP is also used to restore LACP, MAC, ARP, and spanning-tree databases before affected VSX LAGs are returned to normal forwarding. Aruba Networks

Option A confuses the ISL with the keepalive path . The keepalive is a separate Layer 3 mechanism whose primary function is peer-liveness detection during an ISL failure; it is not the channel used for normal ISLP state synchronization. Aruba Networks Option B is incorrect because the ISL itself is a Layer 2 interface/LAG and does not require a routed-only port. Although RPVST is supported with VSX, Aruba ' s documented permanent synchronization examples explicitly identify LACP and MSTP/STP state synchronization , making D the precise answer. Aruba Networks

Study Guide References: VSX ISLP; Inter-Switch Link; Periodic Synchronization; LACP State Synchronization; VSX LAGs; Keepalive.

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Dynamic User Roles require the AOS-CX switch to establish a trusted HTTPS connection to ClearPass Policy Manager (CPPM) so that the role definition can be securely downloaded after authentication. Consequently, the switch must trust the certificate presented by the ClearPass HTTPS service . HPE Aruba specifies that DUR requires a RADIUS server root certificate installed on the switch , and its DUR certificate procedure specifically instructs administrators to create a Trust Anchor profile and import the root CA certificate used to sign the applicable server certificate . Aruba Networks

The crucial distinction is that the downloadable-role transaction uses HTTPS/API communication , rather than the CPPM RADIUS server certificate itself. HPE Aruba documentation for ClearPass certificate validation identifies https-root.pem as the HTTPS root-certificate resource used for DUR trust establishment. Aruba Networks

Therefore, A is the technically correct requirement: install the root CA that signs the CPPM HTTPS certificate . Option D incorrectly associates the trust anchor with the RADIUS certificate. Option C is not universally correct because the required certificate is the relevant HTTPS signing CA, which need not be the ClearPass internal self-signed CA. Option B gives an incomplete/malformed URL rather than the required CX trust configuration.

Study Guide References: Downloadable User Roles; ClearPass Policy Manager Integration; PKI Trust Anchors; HTTPS Certificate Validation; RADIUS/DUR Authentication.

===============

This scenario highlights the " Source of Truth " logic within Aruba Central UI Groups.

UI Group Constraints: When a group is managed via the UI (User Interface) mode, Central acts as the absolute master of the configuration. If you add a switch that already has a local configuration (non-factory default) into a group that already has an established configuration, Central perceives a Configuration Conflict.

The Safety Mechanism: To prevent Central from accidentally wiping out a production switch ' s settings the moment it connects, Central will not automatically synchronize (push) the group configuration to a device that is not in a Factory Default state.

The Resolution: For the switch to synchronize with an existing UI group, you must either:

Erase the startup-configuration on the switch and reboot it (Factory Default), allowing it to " pull " the group config cleanly.

Manually resolve the conflict by moving the device into the group and then selecting the option to overwrite the local configuration with the group configuration.

Evaluating Other Options:

Option A: This is false. Central fully supports VSX monitoring and configuration (specifically via Template groups or the VSX orchestration UI).

Option B: If the switch is " added to a group, " it has already passed the initial onboarding/authorization phase.

Option C: If it " cannot establish a connection, " the switch would show as Offline, not as a synchronization failure within a group.

Aruba Central utilizes a " Top-Down " management model for UI Groups. To maintain the integrity of the network and ensure that the central dashboard remains the " Source of Truth, " specific logic is applied during the onboarding process.

Configuration Conflict Prevention: If a group in Central already has a configuration defined (VLANs, DNS, NTP, etc.), and you add a switch that has its own local startup-configuration, Central detects a conflict. It does not know whether to trust the local switch settings or the group settings.

The Factory Default Rule: To protect the network from unintended configuration overwrites, Central will only automatically sync and push group settings to a switch that is in a Factory Default state. If the switch has an existing configuration, Central marks it as having a " Config Conflict " and stops the synchronization process until an administrator manually intervenes to choose which configuration should " win. "

Evaluating other options:

Option B: If Central weren ' t enabled, the switch wouldn ' t even show up as " connected " or " online " in the dashboard, let alone fail a sync within a group.

Option C: Central supports VSX monitoring and management (particularly through Template groups or specific UI workflows).

Option D: Authorization happens at the " Device Inventory " level. If you have already added it to a group, the device is already authorized.

If interfaces 1/1/53 and 1/1/54 connected to the primary VSX switch are disconnected and Client A experiences disruptions, configuring VSX shutdown on-split on SW-A (the primary) is necessary to prevent traffic forwarding during a split-brain scenario. This feature ensures that in case of link failure, the switch does not continue forwarding traffic independently, avoiding network loops or inconsistent states.

Configuring keepalive VLANs on downstream or upstream lags helps in monitoring but does not prevent traffic disruption.

VSX shutdown on-split must be configured on the affected primary switch to protect network integrity.