How to Fix Active Directory DNS problems

By braniac

Lots of times when creating a brand new domain or promoting a computer that does not have DNS installed or correctly configured, Active directory does not properly configure the DNS name space for your new domain. This can be checked by going into the DNS MMC console and expanding the Forward lookup zone. it should have several sub "folders" such as DC, GC, etc.Errors like: server GUID DNS name could not be resolved to an IP address. Check items such as the DNS server, DHCP and server name. Although the GUID DNS name (._msdcs.domain-name.local) couldn't be resolved, the server name () resolved to the IP address () and was pingable. Check that the IP address is registered correctly with the DNS server. This type of error will cause you to not be able to add computers to your domain, or even add new domain controllers.Obviously, a problem like this is going to bring AD to a grinding halt and provide little to no functionality, so here's how to fix it:

Things You'll Need

  • DcDiag.exe (found in Windows 2000 support tools)

Step 1

Log into the Domain controller either in console or via RDP

Step 2

Download DcDiag.exe from microsoft if you do not have the Windows 2000 support tools installed. You can find it at can download it and extract it to anywhere you like.

Step 3

Open a command window (Start menu -> Run -> Type "cmd" with out quotes and hit enter/click ok), now change directory to where the executable is located.

Step 4

Type "ipconfig /flushdns", then "ipconfig /registerdns" (with out the quotes) to flush out the DNS resolver cache and register the DNS source records, respectively. Some people like to clear the ARP cache as well, you can do this by typing "arp -d *" at the command prompt with out quotes. This part is optional.

Step 5

At the prompt type in dcdiag /fixRead through the output. You will most likely have the following text somewhere in your output:Server GUID DNS name could not be resovled to an ipaddress.Althought GUID could not be resolved, the server name resolved to the ip address x.x.x.x and was pingable

Step 6

Still at the command prompt, type "dcdiag /fix", then "net stop netlogon" and "net start netlogon" (again with out the quotes) to finalize the changes. Run dcdiag one more time to make sure the domain controller's DNS is working. You should no longer get the error mentioned in step 5. Some other NIC related errors may show up, but you can dismiss those for the most part it wont affect your installation (you couldnt get this far if there were serious NIC problems)

Step 7

You should now be able to add member computers to your new domain and add domain controllers.

Tips & Warnings

  • For best effect, make sure you stop and start the netlogon service, do not "restart" it. Restarting may still work, but I have found it less reliable.
  • You will need to be an admin on the domain for this to work.
  • Do not try and manually enter the DNS records. You will most likely miss some key entries, or mistype. This is worse then not having them at all.