DNS Duplicate Records - Domain Controller - Windows Server 2016
Hi all,
We've built a new Domain Controller on a WS 2016 server - old DC's are 2008R2.
Everything appears to be healthy, however, I've noticed that there are some duplicate SRV records on the DNS server of the Domain Controllers - usually one in upper case and one in lower case.
Has anyone come accross this, do you know what the issue is, the resolution and does it cause any problems. I want to make the new server the FSMO role holder and want to ensure that it's a healthy server and domain before I do so.
Thanks for your time
SRV-Records---Duplicates.PNG
We've built a new Domain Controller on a WS 2016 server - old DC's are 2008R2.
Everything appears to be healthy, however, I've noticed that there are some duplicate SRV records on the DNS server of the Domain Controllers - usually one in upper case and one in lower case.
Has anyone come accross this, do you know what the issue is, the resolution and does it cause any problems. I want to make the new server the FSMO role holder and want to ensure that it's a healthy server and domain before I do so.
Thanks for your time
SRV-Records---Duplicates.PNG
footech
When I came across this before, I think I found a blog that discussed the reason behind it, but I don't recall now. Anyway, the fix for me was to delete both records (just one isn't enough, as it will get re-registered and you will be back with two). Then restart the Netlogon service on the DC corresponding with the duplicate records to kick off the automatic registration of records (just one of each will be created).
Here are a few things that can help you out:
https://www.ittechpoint.com/2015/09/how-to-clear-dns-server-cache-and-client-cache.html
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc757041(v=ws.10)
https://blogs.technet.microsoft.com/networking/2008/03/19/dont-be-afraid-of-dns-scavenging-just-be-patient/
https://www.ittechpoint.com/2015/09/how-to-clear-dns-server-cache-and-client-cache.html
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc757041(v=ws.10)
https://blogs.technet.microsoft.com/networking/2008/03/19/dont-be-afraid-of-dns-scavenging-just-be-patient/
Sorry, Danilo, but neither of those apply here. The cache is not involved, and scavenging won't help because these records are automatically re-registered.
Did you see this document on the support forums? Seems like a common problem (and known issue)
https://social.technet.microsoft.com/Forums/en-US/2c547387-7c68-4d15-9917-9569cd8a9650/duplicate-srv-records-for-new-win-2016-dcs?forum=winserveripamdhcpdns
there is a noted solution to do the following to resolve the problem:
We had the same issue and the following procedure fixes the problem:
Rename DC.domain.com to dcnew.domain.com
Reboot
Rename dcnew.domain.com to dc.domain.com
Reboot
Login to server dc.domain.com
Net Stop netlogon
Remove all SRV records related to above domain controller
Remove C:\Windows\System32\config
Remove C:\Windows\System32\config
Net Start netlogon
https://social.technet.microsoft.com/Forums/en-US/2c547387-7c68-4d15-9917-9569cd8a9650/duplicate-srv-records-for-new-win-2016-dcs?forum=winserveripamdhcpdns
there is a noted solution to do the following to resolve the problem:
We had the same issue and the following procedure fixes the problem:
Rename DC.domain.com to dcnew.domain.com
Reboot
Rename dcnew.domain.com to dc.domain.com
Reboot
Login to server dc.domain.com
Net Stop netlogon
Remove all SRV records related to above domain controller
Remove C:\Windows\System32\config
Remove C:\Windows\System32\config
Net Start netlogon
To only remove duplicate NS records renaming DC hostnames is very bad idea
The option suggested by Footech is valid one and I already used it couple of times
The option suggested by Footech is valid one and I already used it couple of times
ASKER
Well on a few occasions, I've stopped netlogon, deleted all of the records relating to that DC, restarted netlogon, and they all re-appear again.
I don't think the duplicates are or will cause any issue, I would just prefer not to have them. Thanks for your advise all.
I don't think the duplicates are or will cause any issue, I would just prefer not to have them. Thanks for your advise all.
Still there is duplication?
ASKER
There is Mahesh, same as before. Apparently this is a known issue with 2016 WS servers
You can leave them AS IS I believe as it won't harm anthing since both points to same hostname
Meantime Microsoft will find some fix for that
Meantime Microsoft will find some fix for that
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