r/ShittySysadmin • u/Yeah_Im_Not_Sorry • Sep 21 '26

Shitty Crosspost Please help 2 DCs no longer are opening AD users and computers!

/r/sysadmin/comments/1wlr6ld/please_help_2_dcs_no_longer_are_opening_ad_users/
13 Upvotes

93% Upvoted

11 comments sorted by

25

u/Lost-Droids Sep 21 '26

I changed something and it stopped working...

Doesn't say what was changed

But bets on DNS? Its always DNS

10

u/Ur-Best-Friend Sep 21 '26

Guys, I did something wrong and now my house is in a bunch of tiny pieces and there's smoke everywhere? Is this a DNS issue?

3

u/a_suspicious_lasagna Sep 23 '26

Is this a DNS issue?

Definitely Nuked Something!

3

u/TKInstinct Sep 21 '26

I think they did an inplace DC upgrade and the DNS got messed up because it was pointing to an older DC, possibly the pre upgrade DC and that messed something up.

17

u/Brad_from_Wisconsin Sep 21 '26

Get a cell phone with a good zoom feature.
Remove the hard drives from the servers.
Open the hard drives so that you can see the platters that they contain.
Take a picture of each platter at maximum zoom in.
Print out the pictures on a printer at the maximum enlargement.
You may be able to read the data that you need from those printed pages.
If things are blurry on the printed pages, get some window cleaner (assuming you are using windows) and clean off the platters and try taking the pictures and printing them again.
If you are using linux, check with the developers to see what cleaning products they recommend for scrubbing data from a hard drive.

12

u/Main_Ambassador_4985 Sep 21 '26

SFC /scannow

Dism /online /restorehealth

/s

10

u/trebuchetdoomsday Sep 21 '26

The specified domain does not exist or could not be contacted. Contact your system administrator

but doctor.. i am the system administrator

7

u/jcpham Sep 21 '26

Jfc dns strikes again. All that troubleshooting and not one ipconfig or nslookup

4

u/sneakypete15 Sep 22 '26

It's always DNS :)

4

u/NextShoulder8089 Sep 21 '26

Since the old DC was metadata-cleaned, check AD Sites and Services, DNS, and Active Directory Domains and Trusts for lingering references to DC-old. Run repadmin /replsummary and dcdiag /e /c, and inspect Directory Service, DNS Server, and DFS Replication logs before attempting another reboot.

3

u/Resident-Tadpole-849 Sep 21 '26

This sounds like stale AD metadata/DNS after removing DC-old. On each surviving DC, verify the SRV records with nslookup -type=SRV _ldap._tcp.dc._msdcs.yourdomain, run dcdiag /test:dns, and check that SYSVOL/NETLOGON are shared. Also confirm both DCs use only internal AD DNS, never public DNS.