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I have a small domain lab set up at home, including DNS/DHCP on the Win2008 server. I'd like to be able to refer to my domain clients by name, but I find that I get a slowdown when using an internal DNS. Win DNS refers to my ISP's upstream dns (I also tried Google's DNS servers for a little while) but it feels like there's an extra couple seconds for each request when I'm using anything except the DNS servers fetched via DHCP from my ISP. I tried adding my local DNS to my router's DHCP (Need to use router to fetch DHCP info from ISP, even though none of it ever changes, since I'm behind NAT)

So, my question is:

Is there any way to set my internal DNS server to be secondary to a dynamically retrieved upstream DNS?

I want the internal server to be queried only if the ISP dns fails, or to be queried only for a certain TLD (.iv right now. I guess for best practices I should change it to .internal)

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.internal isn't considered best practice anymore. Better to use a subdomain of an internet-valid domain you already own e.g. domain.joesblog.com. –  Chris Thorpe Apr 1 '10 at 0:36
    
I've got a DNS server at home on old hardware and it rarely takes more than 100 ms to return a query. If your getting delays that long something is very wrong. –  Chris S Sep 1 '10 at 17:45
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1 Answer

I think the problem is that your Internal server is not acting as a forwarding server for the domains it doesn't maintain, so your client has to wait for it to fail before attempting the other servers. http://technet.microsoft.com/en-us/library/cc754941.aspx explains how to configure Windows DNS server to use forwarders.

This way your internal DNS server is queried for ALL lookups, and for the ones it doesn't know about, it goes and queries your ISPs DNS servers, which takes MUCH less time than waiting for things to fail.

I've got my all my systems at home set up to do this, only I'm running a DNS server on a linux host. The other benefit aside from serving your own domain or hijacking a real domain is that you can fiddle with the cache settings resulting in super-fast lookups from local systems (be careful though, you don't want to cache stuff for a long time if it changes frequently). You can also play fun practical jokes (tomorrow is Aprils Fools day, after all) on your housemates by hijacking say "google.com" and pointing it to bing, or Server Fault, or the porn site of your choice.

Good luck,

--jed

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