I asked part of this question before, but I guess I'm missing something. I'm not clear on HOW to make sure that our DFS-N fault tolerance is configured correctly. We have 2 domain controllers (A and B, both running Win 2008 R2 - domain at 2003 forest functional level). I have installed the DFS Management features on both servers. I created the namespace to using it seems to work well UNLESS server A is down. When server A is down, the shares are inaccessible (drives are mapped via GPO correctly, but you can't open the location). Ideally, we'd like either of our DC servers to handle the requests for namespace resolution when the other is down. I thought I had it configured right (using "dfsutil server xyz" it shows that both servers are hosting the DFS root), but it isn't fault tolerant. I've had a difficult time finding specific information on how to configure this fault tolerance and I'm wondering if anyone has specific instructions on how to configure this.

Just to be clear, we are NOT using DFS-Replication and we're NOT trying to get DFS-R to be fault tolerant, just the Namespace handling.

  • The configuration you're describing should be fault-tolerant. I've certainly got configurations that are similar (DFS namespace with multiple root targets, no replication of the root folder) and I know I've tested fault tolerance. I assume the output of an nslookup domain.com is returning A records for both DCs-- right? Oct 16, 2014 at 0:07
  • Doing an nslookup on a client machine only returns information for server A. Running it on server B returns: Sever: Unknown but the correct IP address. So really it might be a DNS issue more likely?
    – yougotiger
    Oct 16, 2014 at 18:36

1 Answer 1


Based on your comment above I think it's safe to say you have a DNS problem.

For a domain DFS namespace root to be fault tolerant the domain's name must resolve to at least two Domain Controller (DC) computers. This would be the case in a typical "stock" Active Directory environment where each DC would register itself with a blank "A" record at the root of the domain's DNS namespace.

It sounds like you've made some kind of modification that has prevented the "server B" computer from registering itself (or the DNS server accepting the registration). If you correct that you should see fault tolerance of the domain DFS namespace root.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .