"Interesting" prob. We have two DCs that are Windows 2003 Standard X64 servers. They are also primary and seconday DNS for all of our internal hosts. Periodically, client DNS lookups fail. Some quick troubleshooting (open a cmd prompt, do an "nslookup some.host" and get a "Server Failed" message) always leads us back the the DCs. The DNS Manager MMC shows the yellow alert icon on the DNS service that's stopped responding. If we bring up the properties and hit the Monitoring tab we always see that Simple Query says "Pass" but Recursive Query says "Fail". Hitting "Test Now" for immediate verification yields the same results. The solution is simply to restart the DNS service. An immediate check with "Test Now" then will yield a "Pass" for both Simple and Recursive queries. (BTW, both servers have fully populated Root Hints). Has anyone else seen this issue? Any clues or information or troubleshooting steps I'm leaving out? Thanks in advance! // mf

If both DNS servers are running Windows Server 2003 Standard x64, where does 2008 come into the picture?

rrasguy wrote: If both DNS servers are running Windows Server 2003 Standard x64, where does 2008 come into the picture? Comes into the picture because I'm an idiot and *meant* to write "Windows Server 2008 Standard x64" Doh! Sorry! :-) Same questions and issues still apply... // mf

I am experiencing the same problem. About once a day recursive queries fail on my w2k8 server. The server continues to respond to DNS queries from its AD integrated zones, but is unable to resolve any Internet names. No errors or warnings appear in the event logs. A restart of the DNS service temporarily fixes the problem.I have a Win2k8 serverwith AD/DNS/Hyper-V RC1 running. DNS hosts several AD zones and is configured to use Root Hints. No forwarders are configured.Any ideas?Thanks,Jon

We are having the exact same issue. Two 08 x64 DNS servers, the recursive lookups fail. We have discovered that clearing the cache fixes the issue, same as restarting the service would.Does anyone have any updates or resolutions for this?Thanks!Noel Hallnhall(at)clearpointe.com

I too am having the exact same issue. What's odd is that we have 3 sites and 2 DNS servers per site (total of 6 DNS servers). Only two of the servers at one site are showing this problem. They will stop resolving DNS queries at random times until either the service is restarted or the cache is cleared, then it works just fine. I'm running Windows Server 2008 Standard x64 with all latest updates.

What i feel is that your DNS servers are acting fine but edge device is acting smartly (intrusion detection). What device will really do - as packets from DNS server to device use same source port and same source IP, after some time device will think its sort of attack and will start dropping packets.Why it works after restart of DNS service - once we restart DNS service it will start using different source port and now device don't see packet as attack.If you can take a network capture on DNS server while facing issue, you will find that DNS server has send packet to forwarder IP but never received response back.Hope this helpsShilpesh

I have this problem at a client with 2 x 2008 AD servers, one 32bit one 64bit both on identical hardware.Did any of you guys get to the bottom of it?I have found various things on the web to do with virtual memory, NIS ports "ballooning", permissions, using loopbackIP instead of real IP, and so on but I'm still not sure what to do about it.Every few days the staff come in and can't access the internet until the DNS service is restarted on both servers. So why is the DNScache filling up and what can I do about it?ThanksDavid

I also have the identical problem, this was not a problem with the old W2K DNS servers I was using up until a few weeks ago so I doubt this is an intrusion detection issue (as mentioned above). Has anyone had any joy with a fix for this?

This article resolved the issue for us:- http://support.microsoft.com/kb/968372

Thanks! worked solution for me I have Server 2008 R2 Core, DNS This article resolved the issue for us:- http://support.microsoft.com/kb/968372 Arman Obosyan http://postmaster.ge/blog

Just the ticket! I was having the same problem.