mount_smbfs(8): support for SMBv3.02?

O. Hartmann ohartman at
Thu Mar 3 09:47:25 UTC 2016

Does FreeBSD's mount_smbfs(8) support for Microsoft's SMBv3 protocol introduced
with Windows 8 and Windows Server 2012/R2?

I tried to find informations/documentation for the kernel options 
which I suspect to maintain this aspect, but I couldn't find anything regarding
NETSMB or SMBFS. The manpage for mount_smbfs(8) seems not to provide any
further informations. What does option "-n opt" of mount_smbfs(8) do? See
manpage for that sepcific command, it lacks of explanation. 

I'm required to mount a SHARE provided by a Windows Server 2012 R2, which has
explicitely deisabled NetBIOS over 139/tcp (firewalled, too). I'm running
FreeBSD CURRENT, most recent. I'd like to use FreeBSD tools only - as far as
this is possible.

Now it seems that mount_smbfs(8) can not handle SMBv3 - but this is simply a
guess based upon incomplete documentation.

Can someone shed light on the maximal protocol version supported by
mount_smbfs(8)? I need to track down why I can not mount a share with 445/tcp
only. I can do so via 139/tcp NetBIOS from the very same server (windows
2012R2). Since I do not understand much about how windows negotiate the
protocol used with a client's request - if any negotiation ever takes place -
I try to find out what I did wrong with the configuration/usage of

I have running a Samba 4.3 server on CURRENT on which I can set "min protocol"
and "max protocol" as I like. this server does not allow connections via
139/tcp (filtered via ipfw). When setting "min protocol = SMB2" any mount
attempt with mount_smbfs(8) fail, setting the tag to NT1 I'm able to
succesfully connect via port 445/tcp. So for that reason I suspect a problem
with the SMB version negotiated with the 2012 R2 server and the inability of
mount_smbfs(8) (or its appropriate kernel backend) to handle any protocol
version higher than NT1 (or SMB1).

Thanks in advance and kind regards,


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