In what part to look for a problem if it is impossible to connect to AD?

Question

Active Directory

Raised a domain on Zentyal Linux, entered a working machine into the domain successfully. But when checking dcdiag found an error:

TEST: Basic (Basc)
Error: No WMI connectivity
No host records (A or AAAA) found for this DC.

The syntax for the dcdiag command is as follows:

dcdiag /s:dcadm /test:dns

Simply typing dcdiag will not find the main server.
CD pings without problems. DNS CD is listed first in the list on the working machine. The working machine is entered into the domain, enters by login. When a user is added, it is displayed in Active Directory Users and Computers.
CD is connected to Mikrotik. The Firewall list is empty.

Answer 1

At a minimum: check that nslookup returns A-records with the IP address of the domain controller when accessing it via DNS. You may have raised the equivalent of AD DS, but not raised the DNS server, or not configured it enough for the DC to zone the necessary records, as a result, the test fails.
If your DC is named, say, dc.example.com, then there should be entries in the DNS for both dc.example.com and example.com pointing to the DC.