DNS Issue


We have multiple DNS servers in a 2003 AD level domain that we use for Windows 7 clients.  If we do a NSLookup from a client to the third DNS server in the list we are getting "unknown Non-existant domain".  This is a new error and is creating issues routing mail between a couple of domains that we have shared contacts with.

Here is some for info:

DNS Servers . . . . . . . . . . . :

Server:  UnKnown

*** UnKnown can't find Non-existent domain

DNS gives me headaches just thinking about it.  Any ideas on where to start?  Thanks.

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Do you have reverse lookup configured  ?


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Life1430Sr EngineerCommented:
correct ...it occurs when you do not have reverse lookup configured..even if you have check for the PTR record of the DC
Howmany DCs are there in the domain? This occurs and known thing in single DC domain. If you have more than 1 DC then you have to create sub domain zone (_msdcs.domain.local) and restart DNS and Netlogon. However if DCDiag /test:DNS is in passed state then you can ignore it.

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SandeshdubeySenior Server EngineerCommented:
Ensure correct dns setting on DC/clients as this:

Best practices for DNS client settings on DC and domain members.

-Also make sure the IPv6 is configured to dynamic (Automatically) if it is win2008 server.

- Create reverse lookup as other suggested.I will also recommend to check the health of DC too.run dcdiag /q and repadmin /replsum and post the log if error is reported with Ipconfif /all details.
Bruno PACIIT ConsultantCommented:

This error is not an error... This only means you have no reverse DNS zone in your DNS servers to resolve the IP to a DNS name...
That's it.

By the way, having reverse DNS zone is NOT mandatory. Active Directory does not need reverse DNS zone to be functional.

Other experts explained you how to create a reverse DNS zone to avoid the "error" message but personally I'm not sure that your issue is about this.
You may have any DNS issue and linked it to this "error" message (again, it is not an error in fact) but are you sure that creating reverse DNS zone will resolve your issue ???

Can you tell us more about your issue of mail routing (reverse DNS zone misconfiguration may cause issue about spam detecting but it can not cause issue about mail routing...).

Have a nice day
tonyjoewalkerAuthor Commented:
We do have reverse DNS configured.  All I did was move the IP that is registered in DNS to first in the list in the rDNS record and it seems to all work now.  Thank you for all the responses!

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Windows Server 2003

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