does bind caches no replies ?

[Mark_Andrews at isc.org]

> On Sat, Feb 15, 2003 at 11:11:20AM +0400, Ladislav Vobr wrote:
> 
> > discovered that  50% of all my requests (around 1000/sec) are to some
> > specific domain. ( this case happen to me several times in last few
> > days, with infopak.gov.pk or with nopop.net ) All nameservers for those
> > domains were at that time unreachable and were not responding at all.
> > What I have noticed is that for each request I get from customer, my
> > nameservers sends 2-3 requests to each NS records it has for this domain
> > to retry again and again.
> 
> This is a nasty problem plagueing many recursing nameservers. The PowerDNS
> recursor implements query throttling to prevent misbehaving clients from
> further harming remote nameservers: http://doc.powerdns.com/x1814.html
> 
> Your clients will still waste your CPU though, to a certain extent.
> 
> Regards,
> 
> bert

	BIND 9 attaches new queries for the same name/type/class tuple
	to existing queries.
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at isc.org