Hyper-V Error: An authentication error has occurred. The Local Security Authority cannot be contacted.
One of these days, after adding some extra vLans to my Hyper-V server cores, I started to get the error:
“An authentication error has occurred. The Local Security Authority cannot be contacted.
Remote computer: <Hyper-VServerName>“
This error appear when I was trying to connect to a given Virtual Machine using Hyper-V MMC. The same behavior was true when using Virtual Machine Manager console or Virtual Machine Manager Self-Service Portal.
This was a little weird because I could resolve the FQDN of the Hyper-V Host server and Virtual Machines as well… When connecting to these hosts (physical and virtual) using RDP or File share, I saw no problem nor errors…
Hum…
What’s going on here!!! 
I fire up a network sniffer and I saw the Hyper-V physical host trying to get our Active Directory Domain Controller using a broadcast address!!! What!!! I logon into the Server Core, and sure, the DNS settings were missing. These settings were cleared as a result of the latest change that I made to that NIC Team when adding the new VLAns NICs. That explained why the Virtual Machine or my workstation didn’t have any problem to find the VMs or the Physical Hyper-V server, but the Hyper-V Physical host was in trouble trying to validate my request to the closest Active Directory Domain Controller 
Solution:
Check your NIC in the Physical Host were you do the management, and additionally also check for name resolution problems with your DCs.
Woah, you make my day. I am searching for weeks for this error. Never thought about the Hyper-V physical host. We changed one of our DCs, so an old one was switched off, and the IP of that DC was entered as DNS! Thanks a lot.
Michael
Michael Reukauff
April 6, 2010 at 1:06 PM
I am having the same problem but I am unsure how to do what you described. What exactly am I suppose to change?
Jeff Barton
May 15, 2010 at 7:49 PM
Hi
Check you’re using the correct DNS server and no Firewall restrictions are being made between the hosts.
IT Core
May 15, 2010 at 8:58 PM
Got it! We needed to disable the external NIC on the DC. It worked after that.
Jeff Barton
May 16, 2010 at 12:25 AM
Thank you very much,
I lost one day to get the solution
Anonymous
June 4, 2010 at 11:13 AM
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IT Core Blog to the rescue | My ALM Blog
June 14, 2010 at 12:03 PM
I got this error when my password expired. After I changed my password things worked again.
bob
July 14, 2010 at 5:46 PM