authentication failures

[clareq]

We are having a number of intermittent errors on our network, where either pass through authentication fails, but inputting username and password works, or a user loses connection to Exchange for a short period. When this happens you can still ping the exchange server. There is no consistency in where the computer is, or the security level of the user. I've checked, and replication between the two DCs is fine, as is time synchronisation.

 

There appear to be no relevant event log entries, either on the DCs, the Exchange server or the client.

 

Any ideas?

Edited April 22, 2015 by elsiegee40

[clareq]

Anyone? Bump

[penfold]

I had issues regarding authentication which I posted originally as Drive mapping problems. The problem was after an update on one of the DC's but it took a couple of weeks before the problem presented itself. Have you performed any updates recently?

[clareq]

Standard Microsoft security updates - it's the randomness that confuses me. I can lose access to Exchange on one machine, and it work perfectly on the machine next to it.

 

I checked the security event log anyway - no security failures at all.

Edited April 22, 2015 by clareq