DNS server -simple query against this server test fails

2013-03-21

Question

_{Thursday, March 21, 2013 3:00 PM}

Hi all

i have a pdc with platform w2k8r2 which is acting as the dhcp and dns server.

there is also a forwarded dns server.

PDC has a quad network card

1- 192.168.112.28

2- 192.168.112.30

3-10.0.0.1

4- unused

my configuration has been made so that 192.168.112.28 is the main server ip and is used for dhcp and dns.

when i do a nslookup it resolves any server ip address or name.

however when i go in the pdc dns properties and try to do a simple query test.it would fail as well as the recursive.

i did the same on the secondary server but it worked.

i do not find any log related to this issue and i cant figure out why the pdc query test can not pass.

any one can help in ?

All replies (6)

_{Saturday, March 23, 2013 7:40 PM ✅Answered}

Thanks for reply guys,.

well there is an intergrated quad nic additionally some network cards are used for hyperv.

However i found the issue...

The preferred nic was not set to the chosen nic. I selected it and my dns query is working perfectly.

_{Thursday, March 21, 2013 4:21 PM | 1 vote}

More than likely it's due to the multiple interfaces and IPs. That's not a recommended configuration for a DC. It causes other problems, too. MOre on this here:

Multihomed DCs (with more than one unteamed NIC or multiple IPs) with DNS, RRAS, iSCSI, Clustering interfaces, management interfaces, backup interfaces, and/or PPPoE adapters...
http://msmvps.com/blogs/acefekay/archive/2009/08/17/multihomed-dcs-with-dns-rras-and-or-pppoe-adapters.aspx

What is the DC's role requiring multiple interfaces and IPs? Can you offload that role to a non-DC, if possible?

Ace Fekay
MVP, MCT, MCITP/EA, MCTS Windows 2008/R2 & Exchange 2007, Exchange 2010 EA, MCSE & MCSA 2003/2000, MCSA Messaging 2003
Microsoft Certified Trainer
Microsoft MVP - Directory Services
Technical Blogs & Videos: http://www.delawarecountycomputerconsulting.com/

This post is provided AS-IS with no warranties or guarantees and confers no rights.

_{Friday, March 22, 2013 4:07 PM | 1 vote}

Hi nccool,

Yes, I agree with Ace, a multihomed DC is not recommended and it will bring issues.

Active Directory communication fails on multihomed domain controllers

http://support.microsoft.com/kb/272294

Please consider to use only one NIC for a DC so that this kind of issue may be avoided.

Thanks.

Jeremy Wu
TechNet Community Support

_{Sunday, March 24, 2013 3:59 AM}

Glad you figured this out.

Just an FYI, it's really not recommended to multihome a DC. Non-DCs, no problem. At least make sure only one NIC's IP gets registered in DNS for its A host record, the LdapIpAddress record, and the GcIpAddress record (the KB Jeremy posted doesn't address these two records, which are SRV records registered by the Netlogon service). Otherwise, it can cause problems with AD-client communications. After one hour (a DCs's Netlogon service registers this data every 60 minutes), please check to make sure the records aren't being re-registered.

This post is provided AS-IS with no warranties or guarantees and confers no rights.

_{Monday, March 25, 2013 9:03 AM}

Thanks Ace Fekay

is there any documentation for the srv records.

I would like to check it

_{Monday, March 25, 2013 4:08 PM}

What sort of doc, what gets registered or the default registration intervals?

SRV records registered by RWDCs and RODCs.
http://msdn.microsoft.com/en-us/library/cc223809(prot.20).aspx

Missing SRV records?
Ask Premier Field Engineering (PFE) Platforms: The Case of the Missing SRV Records
Tom Moser [MSFT] 9 Jul 2012 5:00 AM
http://blogs.technet.com/b/askpfeplat/archive/2012/07/09/the-case-of-the-missing-srv-records.aspx

There are many more links.

The key point is the DC Locator process uses SRVs for DC location, and on a multihomed DC, there can be multiple records registered causing DNS to provide an IP a client may not have access or route to. Also, it puts the DC into multiple AD Sites, which causes issues. It can snowball. That's why we, and Microsoft, do not recommend DC multihoming, including not making a HyperV server a DC. Why? Because DCs disable the write-cache feature on the drive controllers. Why? To protect the database. But the problem is it vastly reduces performance on the server by quite a bit. Same reason why Exchagne and SQL are not recommended on DCs. It vastly reduces performance. And no, you can't enable write-cache on a DC. It automatically disables it if you try. If HyperV or anyone of these other services are on a non-DC, you can see a tremendous increase in performance. Why not just make a guest DC? That would make more sense, and is the better practice.

This post is provided AS-IS with no warranties or guarantees and confers no rights.

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DNS server -simple query against this server test fails

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