Hello Louis and Mathieu, thanks for your fast reply. I'm using 2:4.5.8+dfsg amd64 from stretch and my Debian machines are members of a Windows 2008R2 DC Active Directory ("net ads join ...") with a single server and about 100 Windows 7 members and 40 Debian members. ("Server role: ROLE_DOMAIN_MEMBER")
I followed the guide from https://wiki.debian.org/AuthenticatingLinuxWithActiveDirectory and changed some settings in smb.conf to fix certain issues after reading 'man smb.conf' (and various online sources from forums, howtos, tutorials, up to https://www.samba.org/samba/docs/* and https://www.samba.org/samba/docs/man/Samba-HOWTO-Collection ) Samba configuration worked acceptable for jessie: about 3 to 8 login issues a day with 40+ Computers and about 60-70 domain logins. Testparm dumps the following service definitions (without shares): # Global parameters [global] realm = WORK.COMPANY workgroup = WORK domain master = No local master = No os level = 0 preferred master = No client ldap sasl wrapping = seal log file = /var/log/samba/winbind-debug.log name resolve order = lmhosts host bcast password server = 172.16.0.1 * restrict anonymous = 2 security = ADS template shell = /bin/bash winbind enum groups = Yes winbind enum users = Yes winbind refresh tickets = Yes winbind use default domain = Yes idmap config * : range = 11000-20000 idmap config * : backend = tdb There are some things missing in testparms output, that are in smb.conf: client use spnego = yes client ntlmv2 auth = yes encrypt passwords = yes log level = 2 winbind:3 template homedir = /home/%D/%U testparm says: "The setting 'security=ads' should NOT be combined with the 'password server' parameter." Since I had problems with WINS and name resolution (e.g. failing nmblookup) I decided to use 'password server' anyway and to remove WINS. I'm only using the tdb backend since SID/uid/gid mapping is not that important for me (I work with temporary user accounts and all user data is stored on the Windows 2008R2 DC in NTFS shares). Homedirs of domain users are created with pam_mkhomedir and deleted on logout. The range starts with 11000 because I had different backends some time ago, but that has been before I installed the current machine. I would like to test samba-4.5.9 or samba-4.6 (or at least the new testparm), but I didn't build samba from sources before. Thanks for your interest, Christian Meyer