How can I increase the TTL for the cached entries in my local dns serveder?

[Graham Clinch]

On 28/03/2014 06:09, Hongyi Zhao wrote:
> In addtition, I also want to have long TTL so that I can obtain a short
> inquiry respond time.

Bind 9.10 might help in this regard - by refreshing cached records 
before they expire, rather than by faking their expiry time.  From the 
change log:

> 3703.   [func]          To improve recursive resolver performance, cache
>                         records which are still being requested by clients
>                         can now be automatically refreshed from the
>                         authoritative server before they expire, reducing
>                         or eliminating the time window in which no answer
>                         is available in the cache. See the "prefetch" option
>                         for more details. [RT #35041]

Note that 9.10 is still in beta (http://www.isc.org/downloads/).

Small nit for ISC - the download page suggests there is an ARM for 9.10, 
linking to http://www.isc.org/downloads/bind/doc/bind-9-10/ - but that 
page contains the ARM for 9.9 (and thus, no details on prefetch).  The 
download for 9.10b2 does contain an ARM with details on prefetch.

Graham

-- 
Graham Clinch
Systems Programmer,
Lancaster University