Active directory Realm error in FMC log.

[scruse]

I'm getting the following errors in the FMC syslog.  I'm not sure this is causing any issue as we are currently in the progress of standing up our firepower implementation and don't have any access policy using any user criteria yet.  I just want to know if this is normal or will this cause problem when we try to use policies based on users?  FMC version is 6.2.3.3-76.

Aug 02 2018 18:09:20 FMC SF-IMS[4764]: [2640] ADI:adi.AdRealm [WARN] normalizeUsername: failed to normalize from userPrincipalName: user@domain for username user@domain

Aug 02 2018 18:09:20 FMC SF-IMS[4764]: [2640] ADI:adi.LdapRealm [ERROR] Unable to retrieve DN for userPrincipalName with value user@domain

[Ashork]

-> LdapRealm [ERROR] Unable to retrieve DN for userPrincipalName with value user@domain

make sure you config Realm correctly(Test and verify) if you have multiple AD servers add these to the realm. download the groups that you need. if you still get the same error, remove the realm and add it again.

[scruse]

Thanks for the quick reply @Ashork.  I verified all AD DC's were configured and tested in the realm and tested the join credentials, but was still getting the errors.  I removed and re-created the realm testing everything along the way and downloaded the groups just fine.  Even after recreating the realm I'm still getting the same errors in the log.  

[Ashork · Accepted solution]

as long as you see the users in ACL's it won't cause any problem. you are just integrating with AD and applying rules based on users. just to be safe create a test acl and apply a identity policy and verify whether your rules are working or not.

[scruse]

Thanks again @Ashork. That's what I was hoping for.  Users show up just fine in access policies and it seems to be working so I'll just ignore the errors in the log.