does smb respond differently to incoming requests on port 445 and port 139?

Christopher R. Hertel crh at ubiqx.mn.org
Fri Nov 18 15:40:44 GMT 2005


On Thu, Nov 17, 2005 at 05:49:58PM -0800, John L.Utz III wrote:
> TNx Gerry!
> 
> 
> 
> At Thu, 17 Nov 2005 19:39:52 -0600,
> Gerald (Jerry) Carter wrote:
> > 
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> > 
> > John L.Utz III wrote:
> > | Hello;
> > |
> > | Heretofore, i had assumed that samba didnt care
> > | if a client connected via 139 or 445.
> > |
> > | However, i've just read some documentation
> > | that indicates that a windows client would
> > | prefer to connect via 445.
> > 
> > port 445 connections avoid the overhead of the
> > netbios layer.  That's pretty much it.

That overhead consists of only two packets:  The NBT Session Request &
Response.

Samba is flexible in this regard.  It will accept this exchange on either
port.  It's also perfectly happy to ignore this exchange on either port.

Windows systems I've tested generally require the NBT Session Request on 
port 139 and fail to respond at all to an NBT Session Request on port 445 
(causing the client to timeout).

The only other overhead would be in service location and name resolution, 
but there is equivalent overhead when using naked transport (port 445) so 
I think it's a wash.

Other than the timeout problem, the overhead of those two packets is 
trivial.

:)

Chridz -)-----

-- 
"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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