1

I have multiple DC in the organization with DNS roles installed on them.

One of the DCs keeps losing its DNS entry.

I flushed dns cache using ipconfig /flushdns

I registered the DC using ipconfig /registerdns

For few minutes all looks fine I can ping the server with hostname and can see the dns entery.

After few minutes the record in DNS server is gone and I cannot ping the server (DC) with host name. I can ping and RDP with IP address.

Any help will be appreciated.

  • Whatever do you mean by "loses its DNS record?" That's a highly ambiguous statement, especially as it relates to Windows domain controllers. – HopelessN00b Nov 22 '14 at 5:20
  • Are you referring to the A record for the DC? Also, ipconfig /flushdns flushes the DNS client cache and is not related to the DNS server component or the registration of AD related DNS records, AFAIK. – joeqwerty Nov 22 '14 at 6:00
1

Check your domain controller for a teamed NIC using third party software. Windows servers don't like teamed NICs prior to Server 2012, and after 2012 you'd better be using Windows's own NIC teaming. However, there's ambiguity on the supported nature of NIC teaming on Domain Controllers as Microsoft documentation never actually directly references the supported or unsupported nature of it and dcdiag sometimes hoses on teamed DCs.

Also check that your DC doesn't have two active NICs on the network. That would be bad on a Domain Controller. It can and will cause DNS problems.

And finally, turn on "Audit Directory Service Access" in Active Directory, then enable auditing in the DNS zone, and you can see what's being deleted in Event Viewer.

  • 1
    What you talking about Willis? NIC teaming has been built in for the last two versions! – MDMarra Nov 22 '14 at 5:19
  • @MDMarra Right, I clarified! – Wesley Nov 22 '14 at 5:34
0

It's unusual for a DNS record to be deleted straight away. It is usually dnsTombstoned first.

You can use ADSIEdit.msc to connect to DC=DomainDNSZones,DC=domain,DC=com, and the zone is located under DC=MicrosoftDNS. If the record is dnsTombstoned, it may still be there.

You can also use repadmin to confirm if the DNS record still exists:

>repadmin /showobjmeta CONTOSOMDDC1 "DC=contosomddc1,DC=contoso.com,CN=MicrosoftDNS,DC=DomainDnsZones,DC=contoso,DC=com"

10 entries.
Loc.USN                           Originating DSA  Org.USN  Org.Time/Date        Ver Attribute
=======                           =============== ========= =============        === =========
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 objectClass
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 instanceType
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 whenCreated
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 showInAdvancedViewOnly
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 nTSecurityDescriptor
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 name
 398215      Default-First-Site-Name\CONTOSOMDDC1    398215 2014-11-21 13:48:09  619 dnsRecord
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 objectCategory
  20501      Default-First-Site-Name\CONTOSOMDDC1     20501 2014-02-03 20:08:18    1 dNSTombstoned
  12646      Default-First-Site-Name\CONTOSOMDDC1     12646 2014-02-03 18:44:13    1 dc
0 entries.
Type    Attribute     Last Mod Time                            Originating DSA  Loc.USN Org.USN Ver
======= ============  =============                           ================= ======= ======= ===
        Distinguished Name
        =============================

There are scenarios where a domain controller will unregister and dnsTombstone its own A record if there is a problem. This can occur even if the A record is static. If dnsTombstone is true, at least you may be able to correlate the time it occurred.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.