I followed the tutorial (tutorial/perfect-server-ubuntu-16.04-with-apache-php-myqsl-pureftpd-bind-postfix-doveot-and-ispconfig/3/) but I can not complete the DNS settings of my server. In registro.br always returns unknown domain. Below are my settings on the server: Can anybody help me?
You missed adding A-records for ns1 and ns2. When the nameservers of a domain are subdomains of the same domain, then you have to add A-Records for them.
You are using fully qualified domains there, check that all of them end with a dot as each FQDN in BIND DNS has to end with a dot.