Randomizing DC IPs on NBT resolution.

Christopher R. Hertel crh at ubiqx.mn.org
Fri Oct 17 20:42:46 GMT 2003

There are three interesting questions raised in the (rather verbose)  
discussion regarding nmbd returning only one IP in response to a <1C>
group name lookup.  I summerize, for brevity...

- When looking up the DC name using the NBNS, it is possible that several
  IP addresses will be returned.  How do we handle that?  Does Samba only 
  ever use the first IP (the PDC IP), or does Samba randomize and use any 
  ol' IP in the list?  My vote would be to use the second IP (if there are 
  two) as that will be the BDC that most recently refreshed its entry.

- Do we count on the fact that WINS puts the PDC IP first in the list?
  That is, we know that WINS always puts the IP of the PDC first in the 
  list of DC IP addresses (in response to the <1C> query).  Samba's nmbd 
  WINS server does the same.  Is there code that relies on this behavior?

- When using DNS to resolve a NetBIOS name to an IP address (I think 
  everyone knows how I feel about this), there are cases in which the DNS 
  server will return a list of IPs.  Does it make sense, if the query is a 
  <1C> query, to return the whole list?  Could there/should there be a 
  special case function that also queries for the <1B> name so that we can
  be sure that the list returned by the DNS has the PDC IP address at the

These go deep.  I'm expecting a resounding silence.  ;)

Chris -)-----

"Implementing CIFS - the Common Internet FileSystem" ISBN: 013047116X
Samba Team -- http://www.samba.org/     -)-----   Christopher R. Hertel
jCIFS Team -- http://jcifs.samba.org/   -)-----   ubiqx development, uninq.
ubiqx Team -- http://www.ubiqx.org/     -)-----   crh at ubiqx.mn.org
OnLineBook -- http://ubiqx.org/cifs/    -)-----   crh at ubiqx.org

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