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sssd to AD fails to resolve some users

This document (7018640) is provided subject to the disclaimer at the end of this document.



Name resolution is pointing to sssd
/etc/nsswitch.conf contains configuration for sssd:

passwd:  compat sss
group:  compat sss

PAM is configured to sssd
/etc/pam.d/common-auth, common-account, common-password and common-session (or service specific files) contain configuration

SSSD is configured with AD backend
/etc/sssd/sssd.conf contains:
id_provider = ad
auth_provider = ad


Error in /var/log/messages:
error: PAM: User not known to the underlying authentication module for <user.domain>

id for user doesn't resolve:
id: <user.domain>: no such user

Other users in the same domain can login and resolve via id

Adding debugging to sssd provides the following error in the /var/log/sssd/sssd_<sssd-domain>.log  
(add debugging by adding:  debug_level = 9 to the /etc/sssd/sssd.conf and restart sssd)

Could not convert objectSID [S-1-5-21-1785213684-45039090-656804464-345103] to a UNIX ID


The defaults for idmap are:

ldap_idmap_range_min = 200000
ldap_idmap_range_max = 2000200000
ldap_idmap_range_size = 200000

Added the following:

ldap_schema = ad
ldap_id_mapping = true
ldap_idmap_range_min = 100000
ldap_idmap_range_max = 2000100000
ldap_idmap_range_size = 2000000000

After making changes to the idmap attributes, the cache files were removed and sssd restarted:

cache files are located at:  /var/lib/sss/db

To restart sssd on SLES 12:  systemctl restart sssd


The user objects that were failing to resolve have very large SID numbers which fell outside the configured range.


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  • Document ID:7018640
  • Creation Date: 17-Feb-2017
  • Modified Date:03-Mar-2020
    • SUSE Linux Enterprise Server

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