[Samba] Re: Understanding the role of DMB/LMB on a net that has a WINS server

David Wuertele dave-gnus at bfnet.com
Thu Oct 9 20:13:47 GMT 2003


John> Have you read chapter 10 of the Samba-HOWTO-Collection.pdf?

What I have already read is this:

http://us2.samba.org/samba/ftp/cvs_current/docs/htmldocs/NetworkBrowsing.html

It looks like they contain the same text as the PDF to which you
refer.  Is it safe to assume that the HTML version I read is current?

John> If this document does not clearly answer your questions please
John> let me know so I can fix it.

Question 1.
Section 10.2 says:

"To most people browsing means they can see the MS Windows and Samba
 servers in the Network Neighborhood, and when the computer icon for a
 particular server is clicked, it opens up and shows the shares and
 printers available on the target server."

>From this, I gather that "browsing" is the act of enumerating and
resolving published share names.  Therefore, a workstation that
doesn't publish any shares, and just uses smbclient or smbmount to
access other servers' shares, must also make use of "browsing."

Section 10.7.1 says:

"Samba facilitates browsing. The browsing is supported by nmbd and is
 also controlled by options in the smb.conf file. Samba can act as a
 local browse master for a workgroup and the ability to support domain
 logons and scripts is now available."

I was not able to discover whether nmbd is *required* to be running on
a workstation that doesn't publish any shares, and just uses smbclient
or smbmount to access other servers' shares.


Question 2.
The closest thing I found to a description of the actual process that
a client goes through in order to "browse" was in 10.3.2 "TCP/IP
without NetBios".  This didn't go into any detail about the client's
logic, but it did give the search order.  Why this chapter is labeled
"without NetBios" is unclear, since one of the client steps is to
"3. Check the NetBios name cache".  I couldn't find where it describes
what a name cache is, but I guess it doesn't matter because the
section that I really care about is 10.3.1 "NetBIOS over TCP/IP".  But
10.3.1 does not go into detail of the client's resolution process.

For example:

If I have a client that wants to enumerate and access shares on a
subnet, and that client knows the IP of the WINS server, is there any
need for the client to use the "browsing" services of a DMB or LMB?

What is the order of operations of the client?  Here is what I imagine
to be the case:

1.  client asks LMB for a list of all available shares
2.  LMB sends client the list of all known shares
3.  for each name in the list of known shares, client asks WINS
    server for the server's IP address
4.  WINS server replies with each name resolution

I can't find anything in
http://us2.samba.org/samba/ftp/cvs_current/docs/htmldocs/NetworkBrowsing.html
that describes what is really happening at this level.  I also could
not find anything that says whether LMBs or DMBs actually do name
resolution.  I also don't understand why we need LMBs if we can always
access a DMB.  I also could not find anything in this document that
talked about the difference between Microsoft's "B" "M" "P" and "H"
hosts.

If there is a WINS server, does there still have to be an LMB and DMB?
If there is an LMB, why does the client need to access the WINS server
directly?  Why not just have the LMB do the resolution?  It would
result in less traffic.




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