SMB shares (sometimes) not accesible by CNAME RRS feed

  • Question

  • I have a problem where on some computers, some users, sometimes have issues accessing certain shares. Looks pretty vague, and it is..

    I'm running an Active Directory Domain on Windows Server 2016. This same server is also the DHCP, DNS and File server. Users log onto different computers with each their own AD-Account. Their AD-Account has a roaming profile and folder redirection to a homefolder.

    Everything was running fine until a couple of months ago. It started with a few users experiencing issues on different computers, with errorboxes that showed the Desktop was inaccessible (\\server\UserFolders$\user\Desktop). Today, this happens more often than it does not.

    The computer has more than one SMB connection to the server. However, some of them work, and some don't. A few facts below:

    '\\server\UserFolder$\user\Desktop' = Not found

    '\\server.fqdn.local\UserFolder$\user\Desktop' = Succesfully connected

    '\\server\OtherShare' = Succesfully connected

    '\\server.fqdn.local\OtherShare' = Succesfully connected

    This seems to me that it had trouble resolving the hostname even though it did resolve it right for the other share. So I checked some resolving:

    ping server [succesfully resolved]

    ping server.fqdn.local [succesfully resolved]

    So it doesn't seem it has to do with DNS as well. So then I found an article (help ticket#3181029 - sorry, can't post urls) which described my problem. I ended up adding the following registry keys:

    • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\SmbServerNameHardeningLevel = 0
    • HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters\DisableStrictNameChecking = 1

    It didn't instantly work, so I assumed I had to restart the LanmanServer on my server. So I did.

    After a refresh on the client, suddenly the desktop was back! I thought my problem was fixed.

    However, after a single reboot. It's inaccessible again.

    Turns out, that restarting the LanmanServer now gives new connection attemps green light, where later on it continues blocking others. But it looks like once it's connected, it stays connected.

    I honestly don't know where to look anymore. I hope someone can help.

    Wednesday, August 26, 2020 11:20 AM