> Source: [sk122477](https://support.checkpoint.com/results/sk/sk122477)

# sk122477 - RADIUS authentication fails for LDAP users as gateway uses sAMAccountName and not UPN when UPN needed

| Property | Value |
|----------|-------|
| Solution ID | sk122477 |
| Date Created | 2018-01-21 |
| Last Modified | 2025-12-29 |
| Technical Level | General |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20, R81.10 (EOS), R81 (EOS) |

## Symptoms

- RADIUS authentication fails for LDAP users as the gateway uses sAMAccountName and not UPN when UPN is needed.

## 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 the Hotfix.  
For faster resolution and verification, collect [CPinfo](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) files from the Management Server and Security Gateways / Cluster Members involved in the case.

**Hotfix installation instructions:**   
Refer to [sk168597 - How to install a Hotfix](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk168597).

**To enable UPN on the Gateway run:**   
`ckp_regedit -a SOFTWARE/CheckPoint/VPN1 radius_auth_prefer_user_input 1`  

**To return to the old behavior run:**   
`ckp_regedit -a SOFTWARE/CheckPoint/VPN1 radius_auth_prefer_user_input 0`

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