ERROR: Authentication Rejected: Unspecified

[frobozz]

Testing a new (first) AAA Server Group (kerberos to Active Directory) on my ASA 5506 using ASDM, I receive:

ERROR: Authentication Rejected: Unspecified

If I supply an incorrect password, I receive:

ERROR: Authentication Rejected: Invalid Password

This leads me to believe the ASA is working fine and it is some problem with active directory.  I have tried several AD accounts, made sure remote access is granted.  Would like to check the Domain Controllers event logs for a clue but have no idea where to start looking - Windows logging has gotten completely out of control....

Any insight would be appreciated.

[frobozz · Accepted solution]

OK, found the problem!  Kerberos realm name (Servers in the Selected Group) not only needs to be all uppercase but also FQDN!!  So you cannot use MYDOMAIN, you must use MYDOMAIN.COM.