Old school DNS question

[kkeville-3s7WtUTddSA at public.gmane.org (Kurt Keville)]

Ah, I had not thought about packet inspection. Thank you.

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  ----- Original Message ----- 
  From: Rob Hasselbaum 
  To: Kurt Keville 
  Cc: discuss-mNDKBlG2WHs at public.gmane.org 
  Sent: Friday, April 01, 2011 3:24 PM
  Subject: Re: Old school DNS question


  On Fri, Apr 1, 2011 at 2:52 PM, Kurt Keville <kkeville-3s7WtUTddSA at public.gmane.org> wrote:

    We have a bunch of nodes that hit a particular DNS server and while we can
    see that name service is running on that server, our queries do not resolve.
    Is there some remote way to find out if they are blocking addresses or
    something like that? We don't have access to the server so checking their
    logs is not an option.



  The dig command is very useful for testing DNS queries. See the man page for all the things it can do, but for simple checks, just invoke it with a domain name argument.

  Pair that with Wireshark, which is a tool that enables you to watch network traffic on your LAN (or at least traffic moving through your network interface). To filter out all but the DNS queries and responses, set the capture filter string to "port 53" in the capture interface options screen.