Identifying and Resolving Duplicate GUID Scenarios using the ResetGuid switch

Products

• IT Management Suite

Issue/Introduction

When deploying Symantec Management Agents (SMA) via disk imaging or cloned virtual machines, multiple computers may report to the Symantec Management Platform (SMP) using the same Unique Identifier (GUID). This results in "flapping" records in the console, where one computer's data is constantly overwritten by another, leading to inaccurate reporting and failed policy deployments.

A Global Unique Identifier (GUID) must be unique to every managed resource. If a machine is imaged without stripping its existing GUID (e.g., failing to run Prepare for Image or sysprep), all machines restored from that image will share the same ID.

It is common to use "AeXAgentUtil.exe  /resetguid". 

[/ResetGUID]

Deletes the Altiris Agent from the registry. The Notification Server resets it.

See Details on aexagentutil.com and AeXNSAgent.com

The /ResetGuid switch is a specialized utility provided with the ITMS agent that allows administrators to force an agent to generate a new, unique identity and re-register with the SMP.

 

Environment

ITMS 8.x

Cause

The most common root cause is a cloned agent identity. This typically occurs when:

1. A "Gold Image" was captured while the Symantec Management Agent was already installed and possessed a registered GUID.

2. The AeXNSAgent.exe /prepareforimage command was not executed prior to image capture.

3. The agent's unique registry keys and files were replicated across multiple endpoints.

 

Limitations of Using /resetguid

Using the /resetguid switch may not be effective when:

• The client was deployed from an image that already contains the Symantec Management Agent (SMA).

• The image includes duplicated identifiers such as DSUniqueID.

Deployment Solution (DS) normally handles GUID uniqueness during imaging, but if multiple systems share the same DSUniqueID, they will appear identical to SMP.

Resolution

About Resetting the Symantec Management Agent GUID

Resetting the Agent GUID can help force a client to request a new GUID from the Symantec Management Platform (SMP). However, this action does not resolve all duplicate GUID scenarios.

If the underlying issue is that two or more machines report the same resource keys, resetting the GUID alone will not correct the problem. In this case, the duplicate GUID is a result of identical resource keys. When SMP receives the same resource keys from multiple systems, it assumes they represent the same resource and merges them into a single record.

This scenario is commonly seen with OEM-imaged systems or improperly cloned images.

How to Validate the Root Cause

To confirm whether duplicate resource keys are causing the issue:

1. Capture basic inventory from the affected machines
   (see KB “Capture processed NSEs on the Notification Server for analysis”).

2. Compare the inventory data to identify which resource key values are identical across the systems.

 

To resolve a shared GUID scenario, you must trigger the agent to discard its current ID and request a new one.

Step 1: Locating the Diagnostic Evidence

Before running the tool, confirm the issue by checking the Agent logs on the affected machines.

• Path: C:\ProgramData\Symantec\Symantec Agent\Logs\

• Evidence: Look for frequent "Register" events or errors indicating that the Server has changed the resource association for a GUID.

Step 2: Running the /ResetGuid switch

The ResetGuid functionality is built into the main agent executable. Follow these steps to execute it manually or via a script:

1. Open an Administrative Command Prompt on the target machine.

2. Navigate to the Agent installation directory (default path): cd "C:\Program Files\Altiris\Altiris Agent"

3. Execute the following command:

   AeXNSAgent.exe /ResetGuid

Step 3: Understanding the Process

Once the command is issued, the following background actions occur:

Action	Description
Stop Services	The SMA service is temporarily suspended
Registry Update	The value in HKEY_LOCAL_MACHINE\SOFTWARE\Altiris\eXpress\MachineGuid is cleared.
Identity Rebirth	Upon restart, the agent generates a brand new GUID locally.
Re-registration	The agent sends a new registration request to the SMP, creating a new, unique resource record.

 

Step 4: Verification

To confirm the process succeeded:

1. On the Client: Check the Symantec Management Agent Settings (double-click the tray icon). The "Unique ID" field should now show a different string than before.

2. On the SMP Console: * Navigate to Manage > Computers.

   • Search for the computer name. You should see a new record created with the recent "Last Configuration Contact" time.

 

Few things to consider:

1. Clarifying the "Merging" Myth: Often customers think ResetGuid merges records. It does not; it creates a new one. The "Old" record in the SMP console may remain as a "retired" or "obsolete" entry until cleaned up by Resource Membership Update.

2. Warning on Software Licenses: Resetting a GUID may cause the SMP to see the machine as a "New" seat, potentially impacting license counts until the old record is deleted or timed out.

 

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FAQ

Q: What happens when aexagentutil.exe /resetguid is run on a machine sharing a GUID with another system?
A: The Symantec Management Agent clears its current GUID and calls CreateResource.aspx, submitting its resource keys. If successful, the agent receives and stores the GUID returned by SMP. The GUID assigned depends entirely on how SMP evaluates the resource keys.

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Q: Is the previous GUID automatically blacklisted when /resetguid is used?
A: No. The agent simply resets its local data. Blacklisting must be performed manually if required.

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Q: Doesn’t Deployment Solution automatically remove GUID references during imaging?
A: Deployment Solution uses a DSUniqueID value to preserve the same GUID during imaging. This key is removed by the SMA once imaging is complete. However, if multiple systems are imaged with the same DSUniqueID, they remain indistinguishable to SMP. In this case, using /resetguid should clear the shared identifiers and request a new GUID—assuming no other identical resource keys exist.

Additional Information

Client Machines are sending same UniqueID during Basic Inventory

Preparing Windows 10 or 11 to run a 'Prepare for Image Capture' (sysprep) task using Deployment Solution 7.x/8.x

What is Agent Blacklisting?