Smb Protocol Version

Home » CentOS » Smb Protocol Version
CentOS 4 Comments

I have a handful of Linux Servers, running CentOS 6.10, and 6.8 with the main host running openvz w/ CentOS 6.10 as the main OS.  Two of the guests are running samba, sharing directories out to windows clients.

I’m in the process of migrating servers over to vmware, using CentOS
7.8.  How can I determine what smb protocol version is being used in the shares for each server?  I don’t see the protocol specified anywhere in smb.conf?

Chris

4 thoughts on - Smb Protocol Version

  • in my CentOS-7 box, /etc/samba/smb.conf contains:

    server min protocol = SMB3_11
    client max protocol = SMB3_11
    client min protocol = SMB3_11

    Some non-current windows versions don’t support that version, you may need to try different values til you find one that works. Whatever you do, you don’t want to use version 1.

    I’m forcing version 3.1.1 only because all the devices I have that support SMB also support 3.1.1, so if someone comes along with, e.g., an old laptop with XP, it won’t be able to insecurely talk to my lan/wan. (and that’s a feature, not a bug! ;=) )

    Also, you may wish to peruse this page:

    https://docs.microsoft.com/en-us/windows-server/storage/file-server/troubleshoot/detect-enable-and-disable-smbv1-v2-v3

  • I don’t have any lines in my configuration file for any of the servers, how can I tell what the default protocols are?

    Are the defaults controlled by samba or the kernel?

    Chris

    —
    Christopher Wensink IS Administrator Five Star Plastics, Inc
    1339 Continental Drive Eau Claire, WI 54701
    Office: 715-831-1682
    Mobile: 715-563-3112
    Fax: 715-831-6075
    cwensink@five-star-plastics.com http://www.five-star-plastics.com

  • Chris,

    CW> I don’t have any lines in my configuration file for any of the servers, CW> how can I tell what the default protocols are?

    you may want to add

    log file = /var/log/samba/log.%m.%R

    to the “global” part of your smb.conf.

    The %R gives “the selected protocol level after protocol negotiation. It can be one of CORE, COREPLUS, LANMAN1, LANMAN2, NT1, SMB2_02, SMB2_10, SMB2_22, SMB2_24, SMB3_00, SMB3_02, SMB3_10, SMB3_11 or SMB2_FF.”

    This will at least give you information about the actually used protocol for every client. A bit “the other way around”, but it might help.

    Michael

  • samba controls this via smb.conf

    See “man smb.conf” for details. The min protocols vary depending on the version of samba you are running.

    Regards,