> Source: [sk13740](https://support.checkpoint.com/results/sk/sk13740)

# sk13740 - RADIUS authentication fails when using passwords longer than 16 characters

| Property | Value |
|----------|-------|
| Solution ID | sk13740 |
| Date Created | 2002-08-16 |
| Last Modified | 2022-11-15 |
| Technical Level | General |
| Products | Security Gateway, Security Management Server, Multi-Domain Security Management Server, Spark Firewall (Locally Managed) |
| Versions | R82.10, R82, R81.20, R82.10, R82, R81.20, R82.10, R82.00.X, R81.10.X, R82.20, R81.20, R82, R82.20 |

## Symptoms

- * RADIUS authentication fails when using passwords longer than 16 characters
* FWM debug shows:

  ```
  
  Administrator USER_NAME was not found in fwm database
  au_realm_set_unique_user_id: Key: CN=USER_NAME,OU=NAME,OU=users,O=NAME
  is_in_remote_auth_group: empty remote_auth_group
  ```

## Cause

A limitation of RADIUS version 1.0 (RFC 2138) limits authentication to 16 characters. In FW-1 the only difference between the two versions is the ability to pack long passwords inside the transmitted packets.

## Solution

Use a RADIUS version 2.0 (RFC 2865) compatible RADIUS Server. Contact your RADIUS Software vendor to ensure version 2.0 compatibility. Configure the RADIUS server object in SmartDashboard to reflect the use of a RADIUS ver 2.0 compatible platform:

1. Open SmartDashboard.
2. Select 'Manage' \> 'Servers'.
3. Open the RADIUS server object properties.
4. Select 'Radius ver. 2.0 compatible', under 'Version'.
5. Click 'OK'.
6. Install the Security Policy to all affected authentication gateways.

<br />

Embedded GAIA devices does support RADUIS ver 2.0 on Locally Managed devices since [R81.10.00](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk179004&partition=Basic&product=Quantum "R81.10.00 for Quantum Spark Appliances")  
firmware version release.

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