[Samba] Re: WINS over subnets - something strange in the HOWTO

Edmundo Valle Neto edmundo.valle at terra.com.br
Tue Oct 3 04:05:17 GMT 2006

John H Terpstra escreveu:
> On Sunday 01 October 2006 18:45, Hoggins! wrote:
>> Edmundo Valle Neto a écrit :
>>> Hoggins! escreveu:
>>> Yes, in that case it should maintain a more complete list. And yes you
>>> just must have ONE WINS server.
>>> I think you didnt got the point, domain master, local master, domain
>>> controllers, wins server, etc are just roles of the same server,
>>> enabling some options in smb.conf the same server can be all of them at
>>> the same time.
>>> BUT, other subnets need local master browsers too, they can be any
>>> Windows workstation (normally you should not worry about that), this is
>>> one of the reasons that all of them must use the same single WINS server
>>> (I am not saying that yours are not), the LMB can be any available
>>> workstation (the machines in the subnet should elect one automatically),
>>> so any machine ending up beeing a LMB will use the  same WINS server to
>>> find the DMB and sync. It works that way without you needing to care
>>> about it.
>>> Ok, if the wireless clients can see each others probably that segment
>>> has an LMB with the browse list of that segment but just isnt passing it
>>> to the samba server.
>>> About the LMBs I just said that to make it clear, that the other
>>> networks dont register themselves directly with samba to be included in
>>> the browse.dat file, who does that is the LMB of that segment (as
>>> explained before).
>> Thanks, I understand better now how it works.
>> So the LMB (any Win machine, elected) of the segment must
>> send its browse list to the server, right ? I must check this traffic
>> with ethereal and/or with debug level 2. Sorry I didn't yet.
> Not quite! 
> The LMB does nothing to contact the DMB. The responsibility for browse list 
> synchronization belongs to the DMB.
> The DMB looks for the LMB registrations in the WINS (wins.dat) database. It 
> then contacts each LMB to synchronise the browse list.
> Ergo, if the WINS database does not contain all machines that are LMBs - 
> browse list synchronization will not happen.
> - John T.


    Look at this at: 

How Browsing Functions

Instead, the DMB serves the role of contacting each LMB (found by asking 
WINS or from LMHOSTS) and exchanging browse list contents.

This is what you said.


Cross-Subnet Browsing

As soon as N2_B has become the LMB, it looks for a DMB with which to 
synchronize its browse list. It does this by querying the WINS server 
(N2_D) for the IP address associated with the NetBIOS name 
WORKGROUP<1B>. This name was registered by the DMB (N1_C) with the WINS 
server as soon as it was started.

Once N2_B knows the address of the DMB, it tells it that is the LMB for 
subnet 2 by sending a MasterAnnouncement packet as a UDP port 138 
packet. It then synchronizes with it by doing a NetServerEnum2 call. 
This tells the DMB to send it all the server names it knows about. Once 
the DMB receives the MasterAnnouncement packet, it schedules a 
synchronization request to the sender of that packet. After both 
synchronizations are complete, the browse lists look like those in 
Browse Subnet Example 2

And thats the another explanation that I said.

Shouldnt that last explanation be different?


Edmundo Valle Neto

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