[cifs-protocol] CAR - missing documentation on *SMBSERVER in SMB and SMB2

Steve French smfrench at gmail.com
Thu Jun 5 18:03:49 GMT 2008

In trying to understand whether Windows Server 2008 allows SMB2
connections over port 139 (due to firewalls for example on 445), I
noticed that it is not documented whether SMB2 connections over port
445 require first sending a RFC1001 SessionInitialize over the socket
(as SMB/CIFS does).   Our experiments indicated that port 139 requests
require the SessionInitalize request, but also showed that connections
to *SMBSERVER failed (*SMBSERVER is the default called name used by
modern Microsoft clients) with "Negative Session Response Called Name
Not Present" (see frames 47 and 48 of attached trace).   It appears
that the behavior of this has changed in Windows Server 2008 which
requires that the user now specify the target system's netbios name in
the session initialize (which did work see frames 8 and 9 of the
attached trace).

Attached is a trace of two mounts to Windows Server 2008 Enterprise -
the first a mount which worked and specified the servernetbiosname in
RFC1001 session init (followed by an umount tree disconnect, ulogoff
of that smb session which is not of interest here) and the second
mount which failed (see frames 47 and 48) which specified "*SMBSERVER"
as the called name and failed.

I would like to see documentation of SMB and SMB2 documents updated to
reflect when the use of *SMBSERVER is permitted and any other
differences in use of 139 (e.g. if SMB2 has additional limitations
when run over port 139 instead of 445).


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