Enabling DFS to Return Folder Targets' FQDNs

How do I enable DFS to return folder targets’ Fully Qualified Domain Names (FQDNs) instead of NetBIOS names?

A. To support clients that might not fully support DNS (which is rare these days), a DFS server refers a client to a folder target by using the NetBIOS target name instead of the FQDN. If your environment no longer uses WINS, NetBIOS names can't be resolved. Also, if you have clients outside your forest using the DFS namespace, they will attempt to resolve the name via DNS and most likely not have the correct DNS suffixes configured to search the correct DNS zones for a match. When that is the case, you need to configure DFS to return the folder target’s FQDN instead of the NetBIOS name.

To enable this change, you must create a DWORD registry value set to 1 at the HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesDfs registry subkey, of name DFSDnsConfig. You need to create this value on all DFS servers that host the namespaces for which you want FQDN referrals enabled. After setting the value, you must restart the DFS service. If you don't update all DFS name servers with the key, clients might have trouble accessing the namespace.

You need to configure this value before you start populating the namespace. When folder targets are added, you must also use the servers’ FQDN. If you already have a namespace with NetBIOS names, you need to delete and re-add the namespace. The easiest way is to use DFSUTIL to export the namespace to a file, then delete the namespace, edit the output file, and change the entries in the file from NetBIOS names to FQDN. Then recreate the namespace, adding root targets by their DNS names. Finally, you must use DFSUTIL to import the updated files.

— John Savill