This issue seems to be related to #12952. I was trying to create a new zone with just a wildcard record which points to a CEPH radosgw. The AD domain is example.com. I executed these commands on an Ubuntu Disco samba domain controller: # samba-tool dns zonecreate $(hostname) s3sub.example.com # samba-tool dns add $(hostname) s3sub.example.com @ A <IPv4_address> # samba-tool dns add $(hostname) s3sub.example.com @ AAAA <IPv6_address> # samba-tool dns add $(hostname) s3sub.example.com '*' CNAME @ Inspecting the zone: # dig @127.0.0.1 axfr s3sub.example.com ; <<>> DiG 9.11.5-1ubuntu1-Ubuntu <<>> @127.0.0.1 axfr s3sub.example.com ; (1 server found) ;; global options: +cmd s3sub.example.com. 3600 IN SOA samba-dc-00.example.com. hostmaster.example.com. 4 900 600 86400 3600 s3sub.example.com. 3600 IN NS samba-dc-00.example.com. s3sub.example.com. 900 IN A <IPv4_address> s3sub.example.com. 900 IN AAAA <IPv6_address> *.s3sub.example.com. 900 IN CNAME \@. s3sub.example.com. 3600 IN SOA samba-dc-00.example.com. hostmaster.example.com. 4 900 600 86400 3600 ;; Query time: 5 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Mon Jan 21 10:20:27 UTC 2019 ;; XFR size: 6 records (messages 1, bytes 248) Using the Windows 2012R2 DNS administrator I removed and re-created the wildcard record with no change in the zone. I was expecting to see the CNAME record data to be just '@' I have worked around the issue by making the wildcard entry this way: # samba-tool dns add $(hostname) s3sub.example.com '*' CNAME s3sub.example.com The samba version is: # apt-cache policy samba samba: Installed: 2:4.9.2+dfsg-2ubuntu2 Candidate: 2:4.9.2+dfsg-2ubuntu2 Version table: *** 2:4.9.2+dfsg-2ubuntu2 500 500 http://gb.archive.ubuntu.com/ubuntu disco/main amd64 Packages 100 /var/lib/dpkg/status