[Samba] On domain join DynDNS issues

[Patrick Goetz]

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