Article Summary: This article provides information on deleting and
recreating the _msdcs DNS zone on a Windows DNS server.
In an Active Directory (AD) domain, the _msdcs DNS zone stores several types
of resource records pertaining to domain controllers (DCs). If this zone is
not present or not functioning properly, domain members may not be able to
locate a DC and thus may not be able to access resources in the domain. When
troubleshooting an issue involving the _msdcs zone, if all other steps fail
to resolve the problem, it may be necessary to delete and recreate the zone.
This article provides the procedure for doing so.
Note: If the _msdcs zone appears to be missing entirely, it may instead
exist as a folder inside the domain forward lookup zone. Verify whether
this is the case before proceeding.
Before deleting the zone, back up the existing data:
- For non-AD-integrated zones, a backup
can be made by simply copying the contents of the %windir%\System32\dns folder.
- AD-integrated zones are stored in
Active Directory. To back them up, back up the system state of a DC that
is also a DNS server.
Once a backup has been made, perform the following steps to delete and
recreate the _msdcs zone:
- Open the DNS console (Start -> All
Programs -> Administrative Tools-> DNS).
- Right-click the _msdcs zone
or folder and select Delete.
Confirm that you wish to delete the zone or folder.
- If _msdcs existed as a separate zone,
Lookup Zones in the
left pane and select New
Zone. Use the wizard to create the zone. Name the new zone _msdcs.domain,
where domain is
the full DNS name of your AD domain. For example, if your domain is
name the new zone _msdcs.mydomain.local.
If _msdcs existed as a folder inside the domain forward lookup zone,
right-click that zone in the left pane and select New
Domain. Name the new domain (folder) _msdcs and
- Right-click your server in the left
pane and select All
Tasks -> Restart to
restart the DNS Server service.
- Open a command prompt and run the
net stop netlogon
net start netlogon
- Wait a few minutes and refresh the
DNS console. The new _msdcs zone
or folder should now be populated with a number of records and
- If there are multiple DCs in the
domain, perform step 5 on each one to register that DC's resource
records in the new zone or folder.
For general steps for troubleshooting DNS issues, refer to this
Quick Tips content is self-published by the Dell Support Professionals who
resolve issues daily. In order to achieve a speedy publication, Quick Tips
may represent only partial solutions or work-arounds that are still in
development or pending further proof of successfully resolving an issue. As
such Quick Tips have not been reviewed, validated or approved by Dell and
should be used with appropriate caution. Dell shall not be liable for any
loss, including but not limited to loss of data, loss of profit or loss of
revenue, which customers may incur by following any procedure or advice set
out in the Quick Tips.