[dns-operations] Client retry behavour?

[Stephane Bortzmeyer]

On Wed, May 09, 2007 at 10:25:08PM +1200,
 Simon Lyall <simon at darkmere.gen.nz> wrote 
 a message of 55 lines which said:

> I was worrying about my recursive name servers [...] The driver
> behind this was did I need to make the primary extremely reliable or
> would clients ( most home users) just use the secondary (and
> tertiary) name servers OK?

My experience on Unix is that the stub resolver included in the libc
takes a long time (several seconds, which is typically unbearable) to
timeout and to move to the second name server listed in
/etc/resolv.conf. Worse, since it has no memory, the problem appears
each time you run a new program.

This certainly makes a case for having a very reliable name server, by
using clustering or anycasting. (Or to install a full resolver on any
Unix machine.)