[Samba] Re: msdfs root problems even after a reboot?

[Josh Kelley]

On 6/4/07, Josh Kelley <joshkel at gmail.com> wrote:
> We upgraded from Samba 3.0.24 to 3.0.25a over the weekend and rebooted
> all of our clients afterwards.  Since then, some of our clients are
> randomly getting the following error:
>
> "Configuration information could not be read from the domain
> controller, either because the machine is unavailable, or access has
> been denied."
>
> Unmapping and mapping the network drive fixes the problem, but one of
> the other admins in our office reports that after remapping a drive,
> it worked for a while, then the problem came back.
>
> Wireshark says that when the client generates this error, it's sending
> a GET_DFS_REFERRAL to the server, and the server is replying with a
> STATUS_NOT_FOUND.
>
> This sounds to me like the result of the change to "msdfs root = no"
> in Samba 3.0.25, but it seems that rebooting and even remapping
> network drives isn't necessarily fixing the problem for us.  Any
> ideas?

In case anyone else has similar problems, we (partially) figured out
what was going on.  If a user maps a network drive with the "Reconnect
at logon" option checked or with "net use /persistent:yes", then
Windows caches whether or not that drive is a DFS root, even across
reboots.  This setting is kept in the registry under HKCU\Network; for
a given network drive connection, if ProviderFlags is 1, it's a DFS
root, and if it's 0, it is not a DFS root.

We fixed the problem by updating our logon scripts to unmap and remap
drives and by instructing users to remap drives if they encountered
problems.

I'm not sure what happened to cause a drive to not work after
remapping, but that hasn't recurred.

Josh Kelley