From the man page for the configuration file for the Samba suite in the "client max protocol" section:

Possible values are :

  • CORE: Earliest version. No concept of user names.
  • COREPLUS: Slight improvements on CORE for efficiency.
  • LANMAN1: First modern version of the protocol. Long filename support.
  • LANMAN2: Updates to Lanman1 protocol.
  • NT1: Current up to date version of the protocol. Used by Windows NT. Known as CIFS.
  • SMB2: Re-implementation of the SMB protocol. Used by Windows Vista and later versions of Windows. SMB2 has sub protocols available.
  • SMB2_02: The earliest SMB2 version.
  • SMB2_10: Windows 7 SMB2 version.
  • SMB2_22: Early Windows 8 SMB2 version.
  • SMB2_24: Windows 8 beta SMB2 version.

By default SMB2 selects the SMB2_10 variant.

  • SMB3: The same as SMB2. Used by Windows 8. SMB3 has sub protocols available.
  • SMB3_00: Windows 8 SMB3 version. (mostly the same as SMB2_24)
  • SMB3_02: Windows 8.1 SMB3 version.
  • SMB3_10: early Windows 10 technical preview SMB3 version.
  • SMB3_11: Windows 10 technical preview SMB3 version (maybe final).

By default SMB3 selects the SMB3_11 variant.

Normally this option should not be set as the automatic negotiation phase in the SMB protocol takes care of choosing the appropriate protocol.

The value default refers to SMB3_11.

Adding clarification from A.B in the comments:

wiki.samba.org/index.php/Samba3/SMB2 states "Samba 3.6 added basic support for SMB2.0", "Basic support for SMB 2.1 was added in Samba 4.0.0", "Basic support for SMB3 is included in Samba 4.0.0 and later."

Answer from Jeff Schaller on Stack Exchange

From the man page for the configuration file for the Samba suite in the "client max protocol" section:

Possible values are :

  • CORE: Earliest version. No concept of user names.
  • COREPLUS: Slight improvements on CORE for efficiency.
  • LANMAN1: First modern version of the protocol. Long filename support.
  • LANMAN2: Updates to Lanman1 protocol.
  • NT1: Current up to date version of the protocol. Used by Windows NT. Known as CIFS.
  • SMB2: Re-implementation of the SMB protocol. Used by Windows Vista and later versions of Windows. SMB2 has sub protocols available.
  • SMB2_02: The earliest SMB2 version.
  • SMB2_10: Windows 7 SMB2 version.
  • SMB2_22: Early Windows 8 SMB2 version.
  • SMB2_24: Windows 8 beta SMB2 version.

By default SMB2 selects the SMB2_10 variant.

  • SMB3: The same as SMB2. Used by Windows 8. SMB3 has sub protocols available.
  • SMB3_00: Windows 8 SMB3 version. (mostly the same as SMB2_24)
  • SMB3_02: Windows 8.1 SMB3 version.
  • SMB3_10: early Windows 10 technical preview SMB3 version.
  • SMB3_11: Windows 10 technical preview SMB3 version (maybe final).

By default SMB3 selects the SMB3_11 variant.

Normally this option should not be set as the automatic negotiation phase in the SMB protocol takes care of choosing the appropriate protocol.

The value default refers to SMB3_11.

Adding clarification from A.B in the comments:

wiki.samba.org/index.php/Samba3/SMB2 states "Samba 3.6 added basic support for SMB2.0", "Basic support for SMB 2.1 was added in Samba 4.0.0", "Basic support for SMB3 is included in Samba 4.0.0 and later."

Answer from Jeff Schaller on Stack Exchange
🌐
Stack Exchange
unix.stackexchange.com › questions › 458203 › available-min-max-values-for-smb-protocol
samba - Available min max values for SMB protocol - Unix & Linux Stack Exchange
Top answer
1 of 1
16

From the man page for the configuration file for the Samba suite in the "client max protocol" section:

Possible values are :

  • CORE: Earliest version. No concept of user names.
  • COREPLUS: Slight improvements on CORE for efficiency.
  • LANMAN1: First modern version of the protocol. Long filename support.
  • LANMAN2: Updates to Lanman1 protocol.
  • NT1: Current up to date version of the protocol. Used by Windows NT. Known as CIFS.
  • SMB2: Re-implementation of the SMB protocol. Used by Windows Vista and later versions of Windows. SMB2 has sub protocols available.
  • SMB2_02: The earliest SMB2 version.
  • SMB2_10: Windows 7 SMB2 version.
  • SMB2_22: Early Windows 8 SMB2 version.
  • SMB2_24: Windows 8 beta SMB2 version.

By default SMB2 selects the SMB2_10 variant.

  • SMB3: The same as SMB2. Used by Windows 8. SMB3 has sub protocols available.
  • SMB3_00: Windows 8 SMB3 version. (mostly the same as SMB2_24)
  • SMB3_02: Windows 8.1 SMB3 version.
  • SMB3_10: early Windows 10 technical preview SMB3 version.
  • SMB3_11: Windows 10 technical preview SMB3 version (maybe final).

By default SMB3 selects the SMB3_11 variant.

Normally this option should not be set as the automatic negotiation phase in the SMB protocol takes care of choosing the appropriate protocol.

The value default refers to SMB3_11.

Adding clarification from A.B in the comments:

wiki.samba.org/index.php/Samba3/SMB2 states "Samba 3.6 added basic support for SMB2.0", "Basic support for SMB 2.1 was added in Samba 4.0.0", "Basic support for SMB3 is included in Samba 4.0.0 and later."

🌐
Red Hat
docs.redhat.com › en › documentation › red_hat_enterprise_linux › 9 › html › monitoring_and_managing_system_status_and_performance › assembly_tuning-the-performance-of-a-samba-server_monitoring-and-managing-system-status-and-performance
Chapter 14. Tuning the performance of a Samba server | Monitoring and managing system status and performance | Red Hat Enterprise Linux | 9 | Red Hat Documentation
The recent Windows and Windows ... the performance improvements. In Samba, the default value of the server max protocol is set to the latest supported stable SMB protocol version....
Discussions
[Question] Set preferred samba protocol version
Current versions of samba should default to smb protcol version 3.11 without any enforced config and smb verson 1 is disabled by default and obsolete with samba. That mentioned there are some desirable settings you can set in smb.conf globally. I've been using the generic standalone config below for several years for a samba server that is not used as a cups print server or with ldap user auth or as an ADC. [global] server string = hostname client NTLMv2 auth = Yes load printers = No printcap name = /dev/null local master = no ldap ssl = no ea support = Yes smb encrypt = desired You can view your samba user connection status by typing smbstatus as the root user and that will display the smb version used as well as encryption algorithm used. Currently my system is using samba 4.11.11 More on reddit.com
🌐 r/linuxquestions
2
6
August 12, 2020
What if I change max samba protocol from SMB3 to SMB4?
There is no SMB4 protocol. You are confusing the Samba version and the protocol. DSM is already on one of the 4.x versions More on reddit.com
🌐 r/synology
6
0
December 10, 2022
bash - Changing Max Client Protocol in smb.conf - Stack Overflow
I have a bunch of CentOS computers for which I would like to change the smb.conf to either enable client max protocol = SMB2 by uncommenting it or by adding it in of it doesn't exist under the [glo... More on stackoverflow.com
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How to add parameter "max protocol = SMB2" to /etc/samba/smb.conf"?
NethServer Version: 6.9 Module: I dont know More on community.nethserver.org
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1
0
May 29, 2017
Videos
11:30
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What is the Server Message Block (SMB) Protocol? - YouTube
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Efficient File Sharing: How to Use Samba and Secure Copy Protocol ...
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27:02
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SMB Protocol Multi-Client Showcase - YouTube
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Samba
samba.org › samba › docs › current › man-html › smb.conf.5.html
smb.conf
The value default refers to the latest supported protocol, currently SMB3_11. See client max protocol for a full list of available protocols.
🌐
nixCraft
cyberciti.biz › nixcraft › howto › samba (smb/cifs) › how to configure samba to use smbv2 and disable smbv1 on linux or unix
How to configure Samba to use SMBv2 and disable SMBv1 on Linux or Unix - nixCraft
May 12, 2021 - Fig.01: How to force SMB2 protocol ... attempt to use. client max protocol – The value of the parameter (a string) is the highest protocol level that will be supported by the client....
🌐
Twardziel
twardziel.eu › it › 3-min-max-protocol-in-smb.conf.pdf pdf
Understanding min and max protocol levels in smb.conf
Understanding min and max protocol levels in smb.conf
🌐
ArchWiki
wiki.archlinux.org › title › Samba
Samba - ArchWiki
May 26, 2026 - When using one these Samba versions, it is highly recommended to set server min protocol = SMB2_02 to protect yourself from ransomware attacks. In Samba 4.11 and newer, SMB2 is the default min protocol, so no changes are required there. Append server min protocol and server max protocol in /etc/samba/smb.conf to force usage of a minimum and maximum protocol:
Find elsewhere
🌐
Samba
samba.org › samba › history › samba-4.1.0.html
Samba 4.1.0 Available for Download
The second way to select SMB2 or SMB3 connections is to set the "client max protocol" parameter in the [global] section of your smb.conf. Setting this parameter will cause all client connections from Samba and its client tools to offer the requested max protocol to a server on every connection request.
🌐
Nslabs
nslabs.jp › samba.rhtml
Samba4でファイル共有 | Netsphere Laboratories
Samba 4.1では, "max protocol" (=server max protocol) 命令のデフォルト値は SMB3 です。こちらはそのままで大丈夫です。
🌐
Server Fault
serverfault.com › questions › 913899 › negotiate-smb2-3-with-a-windows-client
linux - Negotiate SMB2/3 with a Windows client - Server Fault
Top answer
1 of 2
4

The smpd version 3.6.x doesn't support SMB3, so it won't recognize it. Using max protocol = SMB2 should enable the SMB2 support, so start with it. If you then add min protocol = SMB2 the list gets quite narrow...

The LTS support for Debian 7 "Wheezy" ends on May 31, 2018. That's in less than a week. Upgraded Debian 9 comes with smbd 4.5.x, and SMB 3.0 is supported since smbd 4.2. It will support your max protocol = SMB3.

2 of 2
2

@Esa Jokinen already answer you, and I think his answer will solve your issue.

Let me give some more details, Here is a link for the explanation on how and what should you do for enable the SMB2 on your Samba (3.6.x). (look for "SMB2 support")

In generally just do the following:

  1. In the smb.conf [global] section add max protocol = SMB2
  2. Restart your Samba.
🌐
Gen
support.gen.uk › kb › faq.php
Setting SMB Versions in Samba Server - GEN HelpDesk
- client … protects any outbound connections Samba makes (e.g. to a Windows DFS or a backup target). ... [global] # ----- Server side ----- server min protocol = SMB2 # reject SMB1 (CIFS) server max protocol = SMB3_11 # use the latest SMB3 version you support # ----- Client side ----- client min protocol = SMB2 client max protocol = SMB3_11
🌐
Reddit
reddit.com › r/linuxquestions › [question] set preferred samba protocol version
r/linuxquestions on Reddit: [Question] Set preferred samba protocol version
August 12, 2020 -

There are multiple SMB protocol versions that can be set used, by editing /etc/samba/smb.conf 

[global]
    min protocol = SMB2

I can set a minimum, and maximum version for my system. However, this could leave a range of versions that are actually used.

Is it possible to set a preferred version, which is used if both the client and server support this version?
Or is there a way to get SMB to use the latest compatible version, not the minimum (seeing as it defaults to version 1.0)?

Top answer
1 of 2
1
Current versions of samba should default to smb protcol version 3.11 without any enforced config and smb verson 1 is disabled by default and obsolete with samba. That mentioned there are some desirable settings you can set in smb.conf globally. I've been using the generic standalone config below for several years for a samba server that is not used as a cups print server or with ldap user auth or as an ADC. [global] server string = hostname client NTLMv2 auth = Yes load printers = No printcap name = /dev/null local master = no ldap ssl = no ea support = Yes smb encrypt = desired You can view your samba user connection status by typing smbstatus as the root user and that will display the smb version used as well as encryption algorithm used. Currently my system is using samba 4.11.11
2 of 2
1
No, and you shouldn't try, Windows and Samba will always start with the highest option first and work down until a version is found that both can use. What you can do and is what Samba did at 4.11.0, is to turn off earlier versions of the SMB protocol, you do this by adding these lines to your smb.conf: server min protocol = SMB2 client min protocol = SMB2
🌐
SambaWiki
wiki.samba.org › index.php › Samba_4.1_Features_added › changed
Samba 4.1 Features added/changed - SambaWiki
The second way to select SMB2 or SMB3 connections is to set the "client max protocol" parameter in the [global] section of your smb.conf. Setting this parameter will cause all client connections from Samba and its client tools to offer the requested max protocol to a server on every connection request.
🌐
Reddit
reddit.com › r/synology › what if i change max samba protocol from smb3 to smb4?
r/synology on Reddit: What if I change max samba protocol from SMB3 to SMB4?
December 10, 2022 -

What if I change max samba protocol from SMB3 to SMB4 in /etc/samba/smb.conf ? Does it affect anything regarding compatibility as the min protocol remains SMB2?

Top answer
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6
There is no SMB4 protocol. You are confusing the Samba version and the protocol. DSM is already on one of the 4.x versions
2 of 2
2
I think your house will explode since SMBv4 is not yet something.
🌐
Stack Overflow
stackoverflow.com › questions › 43409405 › changing-max-client-protocol-in-smb-conf
bash - Changing Max Client Protocol in smb.conf - Stack Overflow
With sed: delete all lines which contain client max protocol = and then replace [global] by [global]\nclient max protocol = SMB2.
🌐
Ask Ubuntu
askubuntu.com › questions › 1341049 › samba-min-protocol-smb3-nmap-report-smbv1
18.04 - Samba min protocol SMB3, nmap report SMBv1 - Ask Ubuntu
Top answer
1 of 1
1

The smb-protocols nmap script checks to see which smb dialects are present on the Samba server.

client min protocol sets the minimum smb dialect that server can use to connect to another server not the minimum dialects that a client to this server can use.

By default the version of samba used in Ubuntu 18.04 sets the server min to NT1 ( smbv1 ) and the max to SMBv3.

If you want to restrict access to this server to SMB3 and SMB3 only you need to set the server min protocol:

server min protocol = SMB3

*Note: there are sub-variants to this dialect:

SMB3_00: Windows 8

SMB3_02: Windows 8.1

SMB3_10: early Windows 10

SMB3_11: Windows 10

By default SMB3 in smb.conf selects the SMB3_11 variant.*

🌐
NethServer Community
community.nethserver.org › support
How to add parameter "max protocol = SMB2" to /etc/samba/smb.conf"? - Support - NethServer Community
Top answer
1 of 1
3
my 2c: samba is not vulnerable to wannacry ramsonware if you keep it updated… disabling such features won’t help you, 'cause if a client get the virus and the logged user has write access to samba shares, nothing can help you. OTOH, disabling such a feature could have some unexpected and undesire…
🌐
Samba
lists.samba.org › archive › samba › 2015-March › 189754.html
[Samba] server max protocol appropriate values
March 4, 2015 - Default: //|server max protocol|/ = |SMB3| / Example: //|server max protocol|/ = |LANMAN1| / -- -James
🌐
Red Hat
docs.redhat.com › en › documentation › red_hat_enterprise_linux › 8 › html › monitoring_and_managing_system_status_and_performance › assembly_tuning-the-performance-of-a-samba-server_monitoring-and-managing-system-status-and-performance
Chapter 13. Tuning the performance of a Samba server | Monitoring and managing system status and performance | Red Hat Enterprise Linux | 8 | Red Hat Documentation
The recent Windows and Windows ... the performance improvements. In Samba, the default value of the server max protocol is set to the latest supported stable SMB protocol version....
🌐
Mageia Forum
forums.mageia.org › en › viewtopic.php
Mageia forum • View topic - [SOLVED] Can't connect to Samba share
November 23, 2021 - # # hosts allow = the hosts allowed to connect. This option can also be used on a # per-share basis. # # hosts deny = the hosts not allowed to connect. This option can also be used on # a per-share basis. # # max protocol = used to define the supported protocol.
🌐
Koozali
bugs.koozali.org › show_bug.cgi
Bug 10485 - Samba: "max protocol" - wrongly implemented?
Bugzilla – Bug 10485 Samba: "max protocol" - wrongly implemented?
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