DNS test . . . . . . . . . . . . . : Failed
[FIX] re-register DC DNS entry 'ForestDnsZones.a.com.' on DNS server '172.16.1.16' succeed.
[FIX] re-register DC DNS entry '_ldap._tcp.ForestDnsZones.a.com.' on DNS server '172.16.1.16' succeed.
[FIX] re-register DC DNS entry '_ldap._tcp.Default-First-Site-Name._sites.ForestDnsZones.a.com.' on DNS server '172.16.1.16' succeed.
FIX PASS - netdiag re-registered missing DNS entries for this DC successfully on DNS server '172.16.1.16'.
[FATAL] No DNS servers have the DNS records for this DC registered.