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Ubuntu - Samba - SMB Protocol Versions

According to the Samba Official Wiki the Linux cifs kernel client has been included in the kernel since kernel version 2.5.42.

SMB3 is the now the default dialect (SMB3.02/SMB3/SMB2.1 dialects are requested by default).

CIFS protocol (and other old dialects) can be selected (by specifying “vers=1.0” or “vers=2.02” in the mount options.

vers=3.11	SMB3_11	Latest, more secure version. SMB3.11 can also be requested (vers=3.1.1). By default SMB3 selects the SMB3_11 variant.
vers=3.10	SMB3_10	Early Windows 10 technical preview.
vers=3.02	SMB3_02	Windows 8.1
vers=3.0	SMB3	Windows 8, Windows Server 2012. Mostly the same as SMB2_24
vers=2.24	SMB2_24	Windows 8 beta SMB2 version.
vers=2.22	SMB2_22	Early Windows 8 SMB2 version.
vers=2.1	SMB2_10	Windows 7, Windows Server 2008 R2. The default is SMB2 is selected.
vers=2.0	SMB2_02	Vista SP1, Windows Server 2008
vers=1.0	SMB1	NT1 i.e. Windows 95, NT 4.0

Specify with “vers=” and consider that the Linux kernel does not fully support all of the features in these new SMB versions. The newest, most secure dialect, SMB3.11 can also be requested (vers=3.1.1).

Add the following lines to /etc/samba/smb.conf

/etc/samba/smb.conf

server min protocol = SMB2
server max protocol = SMB3
client min protocol = SMB2
client max protocol = SMB3
min protocol = SMB2
max protocol = SMB3
client ipc min protocol = SMB2

Configuration to enable SMBv2

Edit smb.conf file:

Find the [global] section and append the following line:

/etc/samba/smb.conf

...
[global]
...
  min protocol = SMB2
...

The following gives best options:

   client min protocol = SMB2
   client max protocol = SMB3