> Source: [sk183677](https://support.checkpoint.com/results/sk/sk183677)

# sk183677 - PDP identifies machine name instead of user during authentication

| Property | Value |
|----------|-------|
| Solution ID | sk183677 |
| Date Created | 2025-07-22 |
| Last Modified | 2025-07-24 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R81.20 |

## Symptoms

- * The Policy Decision Point (PDP) identifies the machine name instead of the user during authentication.
* The authentication agent retrieves a Kerberos ticket associated with the machine account rather than the user account.
* This message appears in the `pdpd` debug log:   
  `[ 6732 8052]@XXX[DATE TIME] [KerberosAuth (NAC::IS::TD::Events)] NAC::CLIENT::AUTH::KerberosAuth::requestFinished: User Kerberos authentication failed`  
  `
  [ 6732 8052]@XXX[DATE TIME] [KerberosAuth (NAC::IS::TD::Events)] NAC::CLIENT::AUTH::KerberosAuth::requestFinished: Authentication failed, trying to purge ticket and retry`

## Cause

After the initial Kerberos authentication fails with a "`General Error`", the code purges the existing ticket and attempts to reauthenticate. However, during this retry:  

* The first attempt uses valid user credentials:  
  `Credentials acquired for 205027@Domain.INT`
* The retry uses machine credentials instead:  
  `Credentials acquired for XXX$@Domain.INT`
This occurs because the impersonation context is lost when the ticket is purged, causing the retry to default to the machine account.

## Solution

[Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.

A Support Engineer will make sure the Hotfix is compatible with your environment before providing it.  
For faster resolution and verification, collect these files:

1. [CPinfo](https://support.checkpoint.com/results/sk/sk92739) file from the Management Server involved in the case.
2. [CPinfo](https://support.checkpoint.com/results/sk/sk92739) file from the Security Gateway / each Cluster Member / Security Group involved in the case.

**Hotfix installation instructions:**   
Refer to [sk168597 - How to install a Hotfix](https://support.checkpoint.com/results/sk/sk168597).

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