Dcdiag Summary of DNS test Results RReg warn

Question

Summary of DNS test results:

                                        Auth Basc Forw Del  Dyn  RReg Ext
        _________________________________________________________________
        Domain: domain

           DC1               PASS PASS PASS PASS PASS PASS n/a  
           DC3               PASS PASS PASS PASS PASS WARN n/a  
           DC2               PASS PASS PASS PASS PASS PASS n/a  

What is causing the WARN?

Answer 1

https://community.spiceworks.com/topic/1982743-dcdiag-test-dns-reports-a-warning

run from an Admin command prompt:

dcdiag /fix

Answer 2

Hi,

To understand the issue more clearly, please run the following command to get more information:

Dcdiag /v >c:\dcdiag1.log
Repadmin /showrepl >C:\repl.txt
Repadmin /showreps
ipconfig /all > C:\dc1.txt
If there are errors, please share a screenshot here! (Please hide the private information)

Best Regards,

Answer 3

I am back to the statement made for LDAP error 81 (Server Down) Win32 Err 58
The problem with dcdiag is that it is cluttered with mostly
No suitable default server credential exists on this system. This will prevent server applications that expect to make use of the system default credentials from accepting SSL connections. An example of such an application is the directory server. Applications that manage their own credentials, such as the internet information server, are not affected by this.

1. A warning event occurred. EventID: 0x00009016

I think I need to clear the above nuisance first.
Repadmin /showrepl >C:\repl.txt only shows success
Repadmin /syncall /APeD shows no errors.

I posted a How to get domain controller certificate? question.