slow non-cached quries

[TMK]

On Sat, Sep 3, 2011 at 2:06 PM, TMK <engtmk at gmail.com> wrote:
>
>> Message: 1
>> Date: Fri, 2 Sep 2011 10:05:42 +0200
>
>> From: TMK <engtmk at gmail.com>
>> Subject: Re: Fwd: Re: slow non-cached quries
>> To: bind-users at lists.isc.org
>> Message-ID:
>>
>>  <CAAKgOtgCoQdSZ2FJC8Y3kL+bj1gUabSB0ohoxnu+DgT8fyF0Hg at mail.gmail.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> On Sep 2, 2011 9:48 AM, "TMK" <engtmk at gmail.com> wrote:
>> >
>> > ---------- Forwarded message ----------
>> > From: "Leonard Mills" <lenm at yahoo.com>
>> > Date: Aug 31, 2011 8:15 PM
>> > Subject: Re: slow non-cached quries
>> > To: "TMK" <engtmk at gmail.com>
>> >
>> > ;; Received 738 bytes from 192.112.36.4#53(G.ROOT-SERVERS.NET) in 3133
>> > ms
>> >
>> > That pretty much is your delay.  Look to your intermediate network
>> segments, especially any smart devices.
>> >
>> >> ________________________________
>> >> From: TMK <engtmk at gmail.com>
>> >> To: Mark Andrews <marka at isc.org>
>> >> Cc: bind-users at isc.org
>> >> Sent: Wednesday, August 31, 2011 4:44 AM
>> >> Subject: Re: slow non-cached quries
>> >>
>> >> On Tue, Aug 30, 2011 at 9:26 AM, TMK <engtmk at gmail.com> wrote:
>> >>
>> >>
> Actually we have around 6 servers. All I need to do is to reduce the
> response time for the uncached responses as much as possible. So will the
> master cache server save maybe 200 sec of the response time which is good
> number is there any other way to force my server to contact gtld servers
> closer to its geoloc in Africa to reduce the round trip times is that
> possible

one of the worst responses time we captured on our network was for
domain : a.root-servers.net (this is represent 5% of our dns traffic).
we got response time up to 30 sec.

I know this queries can be generated by viruses. but I need to know:

why the bind responding so slowly to such domain > 30 sec and if there
is way to reduce such time.(even if it is query from a virus)

Regards,