Hi, we're planning a Samba 3 to Samba 4 upgrade, and we're quite happy with the tests we've done. Everything worked as expected, and I hope that the migration will be done without major issues (famous last words). But we're having some problems with subdomain delegation. Our setup is formed by the Samba server and a DNS server running Bind 9. The DNS server is used both to serve the internal DNS zone (let's say "customer.com") and as recursive caching server. Currently, the internal DNS zone is configured as "master zone", but our plan is to change it to a "forward zone" (pointing to the Samba server) as soon as the migration is done. There is also a DNS zone "dhcp.customer.com" used for DHCP clients, updated automatically by the DHCP server (also running in the DNS server). We would like to keep this zone in the DNS server, mostly because it already works and because we'd like everyone querying the DNS server for everything, leaving Samba 4 like a sort of "hidden master". I've added a NS record for "dhcp.customer.com" (pointing to the DNS server) with samba-tool, but this seems not to be enough. Queries for hosts in this subdomain return a NXDOMAIN result. The Samba server is able to query the DNS server, which in fact is its DNS forwarder, so communications shouldn't be a problem. I've also tried to use the RSAT tools from Windows to add a zone delegation, and it seems to work up to a point: a NS record is added, but it still doesn't work. Besides, a "Validation error. Try again later." (my translation from spanish to english) warning appears when I enter the name and address of the DNS server. So, my question is: what is the recommended way to add subdomain delegation to Samba 4 DNS? Has it any caveats that we should be aware of? Thanks in advance, -- Roberto Su?rez Soto Allenta Consulting <http://www.allenta.com> (+34 881 922 600) ISO 9001, ISO 14001, ISO 27001, EMAS <https://www.allenta.com/iso> Privacidad / Privacy <https://www.allenta.com/mail-privacy>