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Contrary to this SO question this is for a dotted name (, and it doesn't happen straight away. Only after some period of time (quite a long time, possibly days).

In fact this is for my ADSL router and its internal IP address which I have named within the router itself and in my Windows Server 2003 Domain Controller DNS Service. Specifically, is a Active-Directory-backed primary domain.

In fact, an ipconfig /flushdns may fix the problem, but only after a while (about the time it took me to type in this question :-) ).

That doesn't explain the root cause though...

EDIT: My machine that is failing is Windows XP SP3.

Manually transferred from

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I had (and still have) the same problem It seems like every time I do ipconfig /flushdns it goes away but I sometimes do this several times a day without any other changes to my network connection or rebooting. I think the issue is Windows is deciding to use your secondary DNS server more than your primary DNS server for everything other than nslookup commands. Atleast for me, my primary DNS server forwards almost everything to my secondary anyway but my secondary doesn't know about the host I'm trying to ping. To answer your question, I never really found the root cause.

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I'm not surprised Windows caches the "does not exist" response for uses of DNS whereas nslookup explicitly interrogates the DNS server. (It would be nice if we had options to tell nslookup to use, clear and update the cache!) The use of the second DNS server shouldn't be the fault in my case as my second DNS server is the router itself. It knows its own name (of course) but under a different IP address. If that result was cached, I'd get pings and the auto-refreshed web site would display something other than an client-side error. – Mark Hurd Jun 15 '10 at 5:43
nslookup uses its own DNS client, so the problem must be with the Windows DNS client. – paradroid Sep 27 '10 at 16:24

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