CHAP not working with SonicWall RADIUS integration, error "Radius Client Authentication Failed

03/26/2020 33 People found this article helpful 197,320 Views

Description

While integrating the RADIUS authentication with SonicWall with a Windows 2003 Server; the PAP, MSCHAP, and MSCHAPv2 work except CHAP. And while testing the RADIUS authentication; you receive the following error message:

“Radius Client Authentication Failed”

Resolution

In order to support CHAP, user passwords must be stored using reversible encryption in the Operating System. On Windows the “Store passwords using reversible encryption” security policy security setting determines whether the operating system stores passwords using reversible encryption.

This policy provides support for applications that use protocols that require knowledge of the user's password for authentication purposes. Storing passwords using reversible encryption is essentially the same as storing plaintext versions of the passwords. For this reason, this policy should never be enabled unless application requirements outweigh the need to protect password information. This policy is disabled by default and that’s why the RADIUS auth fails with CHAP.

Solution:

Option 1:

Enable the “Store passwords using reversible encryption” security option for the users under user properties on the Domain Controller.