Hi,

We are currently in the midst of a 2003 to 2012 AD Upgrade.

We have 3 sites. Ive upgraded 1 site successfully with like for like DCs. 

The current site I am upgrading, has 3 DCs. Ive upgraded 2 to 2012 and decomissioned the third. So I currently have 2 2012 DCs in this site.

Ive put a CNAME in for the decomissioned DC and pointed it to one of the other DCs. Nothing is broken but I enabled DNS debugging on the 2012 DCs.

The problem is I can still see requests for the decommissioned DC from devices which are pointing to the 2012 servers for DNS.

Ive checked DNS for the domain and can see no reference to the decomissioned DC.

Any ideas? Ive run DCDiag and the domain looks healthy.

• Edited by MessageUndeliverable 16 hours 54 minutes ago

Hi

 Did you already demote old server 2003 from domain??ANd did a metadata cleanup also??

Check for metadata cleanup;

https://technet.microsoft.com/en-us/library/cc816907(v=ws.10).aspx?f=255&mspperror=-2147217396

Also make sure AD DS,DNS,AD site and services,DFS records update.

"can see no reference to the decommissioned DC" i don't understand anything??please explain much clearly...

Hello,

Please make sure in the DNS you should not have the host A and name server record for the old demoted domain controller.

Also ensure that you have updated DNS pointing on the client machines.

After removing the stale record ensure that old DC name should not be resolved.

Regards,

Mitul aka v-2min

Simply remove the old DNS records of the decommissioned DC. That should fix it.

Hi MessageUndeliverable,

Thanks for your post.

You could remove the reference to the DC under the Name Servers tab. To do this, in the DNS console, right-click the domain name under Forward Lookup Zones, click Properties, and then remove this server from the Name Servers tab.

https://support.microsoft.com/en-us/kb/216498

Best Regards,

Mary Dong