> Source: [sk183879](https://support.checkpoint.com/results/sk/sk183879)

# sk183879 - Authentication fails when integrating a Windows Server 2025 Active Directory (AD) environment with Spark Firewall

| Property | Value |
|----------|-------|
| Solution ID | sk183879 |
| Date Created | 2025-09-01 |
| Last Modified | 2026-02-09 |
| Technical Level | General |
| Products | Spark Firewall (Locally Managed) |
| Versions | R81.10.X |
| Platform | 1570R, 1575R, 1500, 1900, 2000, 1600, 1800, 1595R |

## Symptoms

- * When integrating a Windows Server 2025 Active Directory (AD) environment with Quantum Spark appliances, authentication attempts from the Quantum Spark appliance fail.

* The Quantum Spark appliance displays this error message: "*Stronger authentication is required*."

* LDAP authentication that worked with previous Windows Server versions no longer functions.

## Cause

Windows Server 2025 enforces LDAP signing and channel binding by default.

Earlier versions allowed unsecured LDAP (simple bind without signing), but Windows Server 2025 requires secure LDAP over SSL/TLS (LDAPS).

Authentication fails due to missing certificate validation and channel binding enforcement.

## Solution

This problem was fixed. The fix is included starting from:

* [Check Point R81.10.17](https://support.checkpoint.com/results/sk/sk183153) Build 996004721

After installation, do this procedure:

1. On the Windows server, create a certificate for LDAP.

   **Note** - The certificate must be issued by a trusted CA, include LDAP server FQDN, and be installed in The Window Server's certificate store.
2. Run this Clish command on the Security Gateway:

   `set user-awareness ldaps true`

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