Samba 4.15 Features added/changed

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Samba 4.15 is next upcoming release series.

Samba 4.15.0rc1

Release Notes for Samba 4.15.0rc1
July 15, 2021

Release Announcements

This is the first release candidate of Samba 4.15. This is *not* intended for production environments and is designed for testing purposes only. Please report any defects via the Samba bug reporting system at

Samba 4.15 will be the next version of the Samba suite.


Removed SMB (development) dialects

The following SMB (development) dialects are no longer supported: SMB2_22, SMB2_24 and SMB3_10. They are were only supported by Windows technical preview builds. They used to be useful in order to test against the latest Windows versions, but it's no longer useful to have them. If you have them explicitly specified in your smb.conf or an the command line, you need to replace them like this:

  • SMB2_22 => SMB3_00
  • SMB2_24 => SMB3_00
  • SMB3_10 => SMB3_11
Note: that it's typically not useful to specify "client max protocol" or "server max protocol" explicitly to a specific dialect, just leave them unspecified or specify the value "default".

New GPG key

The GPG release key for Samba releases changed from:

pub   dsa1024/6F33915B6568B7EA 2007-02-04 [SC] [expires: 2021-02-05]
      Key fingerprint = 52FB C0B8 6D95 4B08 4332  4CDC 6F33 915B 6568 B7EA
uid                 [  full  ] Samba Distribution Verification Key <>
sub   elg2048/9C6ED163DA6DFB44 2007-02-04 [E] [expires: 2021-02-05]

to the following new key:

pub   rsa4096/AA99442FB680B620 2020-12-21 [SC] [expires: 2022-12-21]
      Key fingerprint = 81F5 E283 2BD2 545A 1897  B713 AA99 442F B680 B620
uid                 [ultimate] Samba Distribution Verification Key <>
sub   rsa4096/97EF9386FBFD4002 2020-12-21 [E] [expires: 2022-12-21]

Starting from Jan 21th 2021, all Samba releases will be signed with the new key.

See also GPG_AA99442FB680B620_replaces_6F33915B6568B7EA.txt


  • bind DLZ: Added the ability to set allow/deny lists for zone transfer clients.
Up to now, any client could use a DNS zone transfer request to the bind server, and get an answer from Samba. Now the default behaviour will be to deny those request. Two new options have been added to manage the list of authorized/denied clients for zone transfer requests. In order to be accepted, the request must be issued by a client that is in the allow list and NOT in the deny list.

"server multi channel support" no longer experimental

This option is enabled by default starting with to 4.15 (on Linux and FreeBSD). Due to dependencies on kernel APIs of Linux or FreeBSD, it's only possible to use this feature on Linux and FreeBSD for now.

samba-tool available without the ad-dc

The samba-tool command is now available when samba is configured --without-ad-dc. Not all features will work, and some ad-dc specific options have been disabled. The samba-tool domain options, for example, are limited when no ad-dc is present. Samba must still be built with ads in order to enable samba-tool.

Improved command line user experience

Samba utilities did not consistently implement their command line interface. A number of options were requiring to specify values in one tool and not in the other, some options meant different in different tools.

These should be stories of the past now. A new command line parser has been implemented with sanity checking. Also the command line interface has been simplified and provides better control for encryption, singing and kerberos.

Also several command line options have a smb.conf variable to control the default now.

All tools are logging to stderr by default. You can use --debug-stdout to change the behavior.

Common parser:

Options added:


Options renamed:

--kerberos       ->    --use-kerberos=required|desired|off
--krb5-ccache    ->    --use-krb5-ccache=CCACHE
--scope          ->    --netbios-scope=SCOPE
--use-ccache     ->    --use-winbind-ccache

Options removed:

-C removed from --use-winbind-ccache
-i removed from --netbios-scope

Duplicates in command line utils


-e is not available for --editor anymore
-s is not used for --configfile anymore


-l is not available for --load-dso anymore


-l is not available for --long anymore


-V is not available for --viewsddl anymore


--user        ->    --quota-user


--log-stdout  ->    --debug-stdout


--log-stdout  ->    --debug-stdout


--log-stdout  ->    --debug-stdout

Scanning of trusted domains and enterprise principals

As an artifact from the NT4 times, we still scanned the list of trusted domains on winbindd startup. This is wrong as we never can get a full picture in Active Directory. It is time to change the default value to "No". Also with this change we always use enterprise principals for Kerberos so that the DC will be able to redirect ticket requests to the right DC. This is e.g. needed for one way trusts. The options `winbind use krb5 enterprise principals` and `winbind scan trusted domains` will be deprecated in one of the next releases.


  • Tru64 ACL support has been removed from this release. The last supported release of Tru64 UNIX was in 2012.
  • NIS support has been removed from this release. This is not available in Linux distributions anymore.
  • The DLZ DNS plugin is no longer built for Bind versions 9.8 and 9.9, which have been out of support since 2018.

smb.conf changes

 Parameter Name                          Description     Default
 --------------                          -----------     -------
 client use kerberos                     New             desired
 client max protocol                     Values Removed
 client min protocol                     Values Removed
 client protection                       New             default
 client smb3 signing algorithms          New             see man smb.conf
 client smb3 encryption algorithms       New             see man smb.conf
 preopen:posix-basic-regex               New             No
 preopen:nomatch_log_level               New             5
 preopen:match_log_level                 New             5
 preopen:nodigits_log_level              New             1
 preopen:founddigits_log_level           New             3
 preopen:reset_log_level                 New             5
 preopen:push_log_level                  New             3
 preopen:queue_log_level                 New             10
 server max protocol                     Values Removed
 server min protocol                     Values Removed
 server multi channel support            Changed         Yes (on Linux and FreeBSD)
 server smb3 signing algorithms          New             see man smb.conf
 server smb3 encryption algorithms       New             see man smb.conf
 winbind use krb5 enterprise principals  Changed         Yes
 winbind scan trusted domains            Changed         No



 Release Notes Samba 4.15.0rc1.