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I have Netgear as router, NetGear itself has 8.8.8.8 set as prim dns. Windows is connected to NetGear and Ubuntu is, while I can

nslookup cf16.eu 8.8.8.8

(it goes on UDP/DNS) I get no response when do

dig @8.8.8.8 cf16.eu from Ubuntu. When +tcp flag is added and it goes on TCP/DNS there is a response. What can be the problem here? I checked that I have always AD Bit flag set in Ubuntu queries, while this is not set on windows, and I cannot see any other differences in packet frames, ANY!. Does dnsmasq which is running on 127.0.1.1 (and it serves well direct requests on UDP) has something to do here?

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1 Answer

Why have yo picked Google's public nameserver as your resolver? The resolver(s) you ought to be using are those that are provided by your ISP via DHCP. Unless you're a Google customer, and 8.8.8.8 is a nameserver given to you via DHCP, there's no guarantee that that IP address should work for DNS resolution.

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Google has explicitly stated that 8.8.8.8 was going to be their publicly available DNS. It should always "just work." –  kmort May 8 '13 at 21:16
    
And it should hold an appropriately long cache and respond as resolver as fast as your local nameservers? I'm sure if the IETF thought that having a centralized public nameserver was best, they'd have wrote the DNS spec around a similar design. Long ago. But they haven't. Its not a good idea to use a distant resolver for all your DNS needs, even Google says its a good idea. –  Nevin Williams May 9 '13 at 10:13
    
I don't recall them saying anything about speed. I think the idea was more that when your small ISP's DNS goes down, you're not dead in the water because there is an easy to remember DNS at 8.8.8.8. You are, of course, completely correct about caching and speed, but it should work in a pinch. –  kmort May 9 '13 at 11:55
    
I'm also looking at the number of people having trouble with 8.8.8.8 in some manner or another. –  Nevin Williams May 9 '13 at 12:59
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