This is a misunderstanding
The DNS column did not reflect the Web server DNS "resolution" but explain the the hostname is saved into the LDAP database has a DNS pointer
So in order to skip this confusion, have added a new column that display the DNS resolution results.
I would like to know why only domain3.org is saved into the LDAP database with a DNS pointer.
Why doesn't it save into the LDAP database domain1.org and domain2.info?
Also, my Server's hostname is ns1.domain1.org and it is not domain3.org
Maybe ... I am confused what you meant.