Browsing Elections and the 'os level' parameter

David Collier-Brown davecb at
Mon Feb 18 05:35:07 GMT 2002

Richard Sharpe wrote:
> Jay Ts wrote:
> >So I have spent the past day running ethereal here, with various
> >combinations of Windows and Samba PDCs and workstations.  I've
> >found what Windows systems use as the OS Type value (os level, in
> >Samba smb.conf terms), and I'm hoping y'all can take a look
> >at this and let me know if I'm off anywhere, or missing anything:
> >
> >Operating System and Configuration     OS Type value
> >------------------------------------------------
> >(MS-DOS or Win 3.x, with Microsoft     ?
> >       Network Client installed)
> >(Windows for Workgroups)               1
> >Windows 95                             1
> >Windows 98                             1
> >Windows Me                             1
> >(Windows NT 3.x Workstation)           16
> >(Windows NT 3.x Server, member server) 16
> >(Windows NT 3.x Server, as PDC)                32
> >(Windows NT 4 Workstation)             16
> >Windows NT 4 Server, as member server  16
> >Windows NT 4 Server, as PDC            32
> >Windows 2K Professional                        16
> >Windows 2K Adv.Server, as member server        16
> >Windows 2K Adv.Server, as NT-PDC       32
> >(Windows XP Home)                      16
> >Windows XP Professional                        16
> >
Richard Sharpe wrote:
> These are the values I recall seeing, and this makes sense according to
> the browsing docs that MS provided that I saw. I think some of this is
> in the CIFS doc now.
> Of course, since I originally wrote the code in Ethereal that dissected
> these things, you might want to use another monitor tool to cross check :-)

> >One thing to go along with this: it seems that Windows and
> >Samba both compare the OS Type values as integers rather than
> >bits, 

	Which explains how the other bits affect
	the behavior so oddly.

	This was a subject of some debate back when the
	book was first written: 

> >         so an "os level" of 33 for Samba will beat a Windows
> >system having an OS Type of 32, even though ethereal reports an
> >value of 33 as a system that is both Windows NT Server and
> >Windows for Workgroups (i.e., 32 anded with 1).  In other words,
> >it is not necessary to use the next bit over (64, or even 65 ;)
> >to win against any Windows PDC.
> >I think it would be a good idea to get the OS Type values clear
> >and document them so that the users will know exactly how to
> >get Samba to beat or lose elections against specific Windows
> >versions.

	Strongly agreed!

David Collier-Brown,           | Always do right. This will gratify 
Performance & Engineering      | some people and astonish the rest.
Americas Customer Engineering, |                      -- Mark Twain
(905) 415-2849                 | davecb at

More information about the samba-technical mailing list