DNS: _msdcs.boba.com can not be reloaded


1) I have 2 machines: dc1 and dc2
2) DC1:
-Windows 2003 server
-It is a Domain Controller
-Active Directory environment
-Domain: boba.com
-DNS server
3) DC2:
-Windows 2003 server
-It is a Replica Domain Controller
-Active Directory environment
-Domain: Boba.com
-DNS serve
4) Problem: When i open a DNS console at DC2, under "Forward Lookup Zones", By mistake, the "_msdcs.Boba.com" was deleted.
-I tried to reload it again but failed
-The message: "Zone not loaded by DNS Server"
5) My questions: Please say it with your own wording firstly, and you can provide any links if necessary: i)What is the FUNCTION of this "_msdcs.Boba.com"?, ii) IS it an important zone or just a complement which we can just ignore it?, iii) How to fix it?
6) Thank you

Who is Participating?
Chris DentConnect With a Mentor PowerShell DeveloperCommented:


It holds the majority of Service Records for your AD Domain. Clients use those to locate Domain Controllers and all associated services.


Very important.


So you had a separate Forward Lookup Zone for _msdcs? And you deleted it through the DNS Console?

When you say "Reloaded" do you might right click on a version of the zone and select Reload? That wouldn't do any good if so, where did you attempt to do that?

Do you also have a Greyed out version of _msdcs under your boba.com forward lookup zone?

Either, create a new Primary, Active Directory Integrated zone called _msdcs.boba.net, or delete the greyed out folder called _msdcs from boba.net. If recreating the zone, ensure Dynamic Updates is enabled, and set it to replicate to all DNS Servers in the Forest (if that is a choice here).

Once the zone is back, restart the NetLogon service on each of your Domain Controllers. That forces re-registration of the records within that zone.


tjieAuthor Commented:
Hi Chris,

1) This is a good approach
2) I could not delete the "greyed out folder of _msdcs.boba.com". The error message: "file is not exist"
3) So i created a new "_msdcs.boba.com"
4) Stop and restart the "net logon"
5) And NOW i got back the _msdcs.boba.com, but i have TWO of them now; should i delete one of them?
6) The other question (not related to this) (just curious): Do you know the meaning of _ ("under score") at the front of _msdcs.boba.com?
7) Post it back please
8) Thank you

Chris DentPowerShell DeveloperCommented:


I'm a little concerned about that error message. It should happily let you delete the delegation. Could you tell me the Replication Scope for the DNS Zone? And if the DNS Service is logging any errors or warnings in the Event Log?


Two separate zones? Or the normal one and the greyed out folder? The greyed out version is a Delegation and should be maintained if _msdcs is kept separately.


The underscore is used as part of Service Record definitions with formatting discussed in http://www.ietf.org/rfc/rfc2782.txt.

It's difficult to say why it has an underscore as a prefix, I suspect it's largely because it will not conflict with any existing public name (underscores are generally not supported in DNS names, Service Records are the exception to this). It is conceivable, if unlikely, that someone may have an "msdcs" sub-domain separately from AD otherwise.

I couldn't tell you what MSDCS itself stands for, it's extremely hard trying to find that answer.

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