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Having a weird issue involving what I believe to be DNS, had a DC die over the night, Rebuild the Controller with a backup. Everything went fine, everything checked out except it using Auto DHCP and DNS. (This business does NOT have great documentation; I have been trying to fix that) SO, No documentation and the previous configuration, I was able to find the previous static assigned and set DNS up to look at itself. Now this all worked fine at first. We had a guy onsite attempt to join a computer to the Domain and the Domain wasn’t reachable, Pingable but it acted as if the Domain wasn’t functioning. NSlook up reported everything looked correct, Had the guy apply the server DNS as the primary on said device and it was able to communicate with the server and be domain joined, however if you set it back to auto it again can’t see the Domain controller. I feel like I’m missing something painfully obvious.

1 Spice up
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Did you have a second DC in that domain? If so, you need to forcibly remove the dead DC, then I think you need to look for old entries for the crashed DC, on AD Sites and Services, DNS etc and make sure there are entries for the restored DC. You may find you have both DCs listed in some places. If you did have a second DC, a better course of action would have been, forcibly remove the dead DC, do a clean up afterwards. How to demote a Domain Controller: A step-by-step guide - Windows Active Directory . then deploy a second DC and let it replicate from the surviving DC. Also remember to consider the FSMO roles. How to Seize FSMO Roles From Dead Domain Controller? – TheITBros

Keep us posted!

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Hey! Thanks for the reply, so they did not have a secondary in place, I am going to build one once i get DC01 Fixed. Dead DC has already been removed and cleanup was done. Essentially the new DC is an exact clone of the original. Excluding the DNS and Static IP were not the same (They are now). I can get some screen shots of everything i am seeing that doesn’t look correct. The catch here is literally everything works perfectly fine if i tell the workstations or laptop to force DNS to the domain controller. The oddest thing i have seen is reverse lookup is basically empty.

Would it be best to just spin up a new DC now, get it configured and replication done, Demote DC1 remove it and basically start from scratch?

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how to clients get their ip address informaiton assigned? If dhcp what is the dhcp server? Check it’s settings. It is strange that this has changed (i.e. you set the recovered DC to the same IP so it shuld just be working).

What form of restore from backup was used? The restored DC should have had the static IP previoulsy set and all other settings be the same.

The clients should be set to use the DC for thier DNS - and only the DC (not just primary).

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@matt7863 ​ I ended up figuring it out, Sorry for the late response. Issue was actually related to the Access points vlan. Basically before i started with this MSP (They hired me to clean up all of their clients, its a shit show) The server (DC) had died, They pointed the firewall to use 192.x.x.x addressing to bypass the DHCP server so users had internet. Failed to tell me this while I fumbled around trying to figure things out. All the switch ports were vlaned incorrectly and the APs were giving out a .198 and couldn’t communicate with the domain controller. Still a ton of work to do, But as this client is a school and school starts next week i just spun up a new SSID with the correct vlan and had the students connect to it, Then used a script to domain join them with no issue and will get them fixed come December.

Appreciate everyone’s help!