Windows Server 2012: Allow traffic by MAC address

I joined a company recently and the System and Network admin left with "secrets". I'm stuck newly computers I'm building and external client computers that are meant to share some resources on my our domain: - Newly built Windows 10 PCs cannot join the domain. I get the message "An active Directory Domain Controller for the domain domain_name could not be contacted..." Here is the DCDIAG.TXT file it is pointing to:

"The domain name "domain_name" might be a NetBIOS domain name. If this is the case, verify that the domain name is properly registered with WINS.

If you are certain that the name is not a NetBIOS domain name, then the following information can help you troubleshoot your DNS configuration.

The following error occurred when DNS was queried for the service location (SRV) resource record used to locate an Active Directory Domain Controller (AD DC) for domain "domain_name":

The error was: "DNS name does not exist." (error code 0x0000232B RCODE_NAME_ERROR)

The query was for the SRV record for _ldap._tcp.dc._msdcs.domain_name

Common causes of this error include the following:

• The DNS SRV records required to locate a AD DC for the domain are not registered in DNS. These records are registered with a DNS server automatically when a AD DC is added to a domain. They are updated by the AD DC at set intervals. This computer is configured to use DNS servers with the following IP addresses:

  xxx.xxx.xxx.xxx
  xxx.xxx.xxx.xxx
  

• One or more of the following zones do not include delegation to its child zone:

  security
  . (the root zone)
  "
  

Besides I have the same sort of message when launching rdp machines that are not in the same subnet or lan.

I heard that somewhere on the DC, the former administrator set mac addresses recognition rule. I have searched so far and no solution. Can someone help. I'm desperate.

I was finally able to have the login popup and join my computers to the domain by providing the DNS server ip in the network setup.