DFS and Mapped Drives RRS feed

  • Question

  • In the past week I have had two users (in separate AD Sites) complain about not being able to access the targets under a DFS namespace root that is mapped to a drive (\\domain.local\DFS).  Oddly enough, it has been fine for a number of years (maybe two issues in the whole time).  I recently added another folder target under it (\\domain.local\DFS\Share), but don't understand why this would be an issue....

    To clarify, you can open the "W drive", see all the folder targets, but cannot access them.  When you try to access them sometimes the screen just refreshes, sometimes it sends you back to my computer, and sometimes you get this error:   <drive>:\<share folder name> is not accessible. An unexpected network error occurred.

    More info:

    - DFS namespace is 2008.  No DFS-R with this one anywhere.

    - Name space server in each site

    - I always use the FQDN for target paths

    - Windows 7 (32 and 64 bit)

    - DFSUtil /pktflush doesn't help***

    - When accessing via UNC it is fine

    - If I were to remap the drive, it would be fine

    **Since pktflush doesn't actually work around the issue I am reluctant to apply this hotfix:  http://support.microsoft.com/kb/983620/en-us

    When things were not working, I mapped another DFS namespace root to a drive and took some packet captures for comparison (see images).  Before connecting I flushed the pktinfo cache.  As you can see, it's like the one that doesn't work completely skips the step to connect to the IPC$ share to get referral info.  However, after I do dfsutil /pktinfo everything is fine.

    Anyone seen this and know what I could do aside from TRY a hotfix (eek)?  I disable SMB2 on all my clients and servers via group policy registry settings because we have some applications that it does not play well with.....  I'm afraid this is going to get worse.

    Friday, April 11, 2014 4:58 PM