[Samba] Running smbd 4 + nmbd 3?

[Lou]

Hi!

I'm a long time Samba user, but I soon started to administer a machine with smbd
daemon that provides file sharing using SMB1 (!).

One of the things we would like to do is to is to stop using SMB1 and start
using recent versions of the SMB protocol.  Unfortunatelly we are running, in
another machine, an old version of nmbd that talks an old protocol (NT4? - how
can I verify that?).  The latest version of samba3 supports SMB2 only
experimentally.

The ideal situation would be to upgrade everything to Samba 4 and use AD
protocols.  I'd like to make it in phases, though.  Because of Windows 10
requirements and security reasons, the first thing I'd like to do is to upgrade
smbd to the latest version (>4), provide SMB2 or later to clients, but for now
it would be necessary to work with the old nmbd daemon.

I have looked for some information about some hybrid environment , but found
nothing.  Must of the documentation assumes you are running the same version for
smbd and nmbd so I start wondering if this is really possible.  Is it?

Thanks.