Since this has come up a lot, I'll just add another example of the DNS stuff not working correctly. Ubuntu 20.04, Samba 5.4.15. This hasn't been a problem previously with Ubuntu 20.04/Samba 4.13.17/sssd 2.2.3 binding to the same domain. root at cns-khl-files:/etc# net ads join -U cns-pgoetz Password for [AUSTIN\cns-pgoetz]: Using short domain name -- AUSTIN Joined 'CNS-KHL-FILES' to dns domain 'austin.utexas.edu' DNS Update for cns-khl-files.clm.utexas.edu failed: ERROR_DNS_GSS_ERROR DNS update failed: NT_STATUS_UNSUCCESSFUL This seems unrelated to the method used to join the domain, but this is the command I've been using to join the domain on sssd-based systems where the failed DNS thing never happens: # adcli join --domain=AUSTIN.UTEXAS.EDU --login-user=cns-pgoetz --host-fqdn=CNS-CRYO-RITA1.AUSTIN.UTEXAS.EDU --service-name=host --service-name=RestrictedKrbHost --show-details --verbose