Using forwarders

Peter Dambier peter at
Wed Jun 25 06:18:40 UTC 2008

An example from DTAG.DE germany.

I share my aDSL with some 32K end users.

95% of my queries are not in the cache.

An answer from my ISPs first nameserver almost never returns.
An answer from my ISPs second nameserver takes either 80msec (cache) or 3.3 secs.

I guess now you understand why my neighbors DSL16K is slower than my DSL 1K :)

My own resolver (bind 9.4) returns after 3msec (cache) or some 400msec.
95% of my queries are in the cache now.

Of course even cheap routers today have a built in cache. So reality looks bright.

Barry Margolin wrote:
> In article <g3s35f$2mmi$1 at>, Brian Feeny <bfeeny at> 
> wrote:
>> So can anyone think of practical reasons why one would want to set
>> forwarders to their ISP?  I mean, even pooling to a much larger DNS cache
>> (The ISP) doesn't seem like a big win.  
> Didn't we just discuss this a week or two ago?  Basically, it's a 
> frequent point of debate about whether the benefit of sharing a big 
> cache is worth the extra delay when something isn't in the ISP's cache 
> and the dependency on a third party server's reliability and performance.

Peter and Karin Dambier
Cesidian Root - Radice Cesidiana
Rimbacher Strasse 16
D-69509 Moerlenbach-Bonsweiher
+49(6209)795-816 (Telekom)
+49(6252)750-308 (VoIP:
mail: peter at

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