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benjamin_gate
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May 02, 2019

Fred - nicely done here.

 

Need to pick your brain on this please kind sir!

 

We use this on our system for 6K mailboxes with 4 Exch2010 nodes in the backend. Strange problem came up the other day and below is the workaround I've found but do need a solution if you can explain what I'm missing please?

 

Symptom

 

Outlook (any version) is randomly prompting a few arbitrary users for Windows credentials.

 

Reproduction of issue & workaround

 

  • Outlook user using Outlook Anywhere is disconnected [for whatever reason, e.g. Hibernate, no network, etc].

     

  • Next time they connect, Outlook prompts for credentials; not every time though - happens randomly.

     

  • Searching APM logs for the user's AD username shows '...username@domainsuffix...WRONG PASSWORD...'

     

  • We know the password is valid because said user can then login on another machine (i.e. not their usual machine) and authenticate just fine through Outlook.

     

  • Any other user can log in to Windows on the affected user's usual machine and authenticate just fine through Outlook.

     

  • Delete the affected user's Windows profile on their usual machine and then create a new Windows profile on it.

     

  • Affected user can now login and authenticate just fine through Outlook.

     

Sledgehammer I know, but it works.

 

Questions

 

  1. Why does it work?

     

  2. What file can I delete to prevent having to delete the whole Windows profile?

     

  3. What's gone pearshaped with APM that's causing this?

     

Bit of historical context for you sir...

 

The last time this happened, we bounced the passive BIG-IP, then switched over to it - all good, and then bounced the active, then switched back - all good. F5 support had no explanation for why that resolved the symptoms.