Bind 9.3.2 - how do i know dns is using which root server

[Alex Tang]

it is because our cache only dns was upgraded to 9.3.2 from bind 8, we want to find out that can it use the nearest root server to query ? We have a BGP session with a root server which is located in the local exchange. Therefore, we want to find out some log to show which root server will be use if the dns server need to query root server.

otherwise we need to use sniffer or snoop to obtain those information.



-----Original Message-----
From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org]On
Behalf Of Kevin Darcy
Sent: Thursday, March 09, 2006 12:32 AM
To: bind-users at isc.org
Subject: Re: Bind 9.3.2 - how do i know dns is using which root server


Alex Tang wrote:

>Hi All
>
>Please help
>
>how do i know dns is using which root server to query per request ? ( per transaction )
>
Your question is flawed, inasmuch as it seems to assume that a root
server is used for each query. In actuality, what happens is that named
gets the root-zone information at startup via a "priming" query, builds
up a whole hierarchy of cached information as queries come in and the
results are cached, and very rarely needs to go back up to the roots for
anything.

The real question is: why do you care what root server is or is not used
in the resolution of a particular query?

- Kevin