Removing old AD Domain Controller

Question

Hello,

Recently i have added 4 new domain controllers in our domains.

We have 1 forest with 2 domains.

One is root domain and second is used for workstations/servers. So at this moment we have 5 AD DC, two are in root domain and 3 are in workstation/server domain.

One of the 3 is old AD DC - and i want to delete it. All FSMO roles are already moved to new AD DC, all ports are opened and workstations/servers can reach and communicate with new AD DC.

Problem - at this moment i see that most of workstations and servers are still communicating with old DC. I turned off old DC and started to have problems with some server that they still tried to communicate with DC5D etc.

So I find some information about setting DC priority - but i think it wouldn't help.

How could i force all servers/workstations to communicate with new AD DC instead of old, and so this movement will have less problems?

Answer 1

Please run;

Dcdiag /v /c /d /e /s:%computername% >c:\dcdiag.log
repadmin /showrepl >C:\repl.txt
ipconfig /all > C:\dc1.txt
ipconfig /all > C:\dc2.txt
ipconfig /all > C:\problemworkstation.txt

then put unzipped text files up on OneDrive and share a link.

Answer 2

Hi,
First of all , we need to make sure that all the new DSs are succefully promoted, and there is no replication problem among DCs.
You can check that by command :
Dcdiag /v >c:\dcdiag1.log
Repadmin /showrepl >C:\repl.txt
Repadmin /showreps * 

If there are no problems, you can demote the old DC and make a metadata cleanup if necessary.(Before this, back up all the old DC ,and one of the new DCs.)

Best Regards,

Answer 3

Hello

i checked the health of all DC - everything is fine. After ir shutdown old DC we started to have problems with users which are using Direct Access. They can't reach the company resources etc. I can't find any information on DA server that indicates old AD IP and hostname.

Direct Access server is communicating with new DC. What should be the cause..?? @Anonymous @Anonymous

After i turned on old DC everything starts working and clients could connect..

Answer 4

After i turned on old DC everything starts working and clients could connect..

Sounds like the problematic ones still have old DNS server addresses. I'd check the DHCP server hands out correct DNS settings. Check DNS settings on member servers and others that are statically assigned,.

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