A question regarding the db.cache file

[Paul Roberts]

Klas Bengtsson wrote:
> Hi again!
> 
> Another question in the same area:
> 
> What if I instead of using the db.cache file list my name servers as 
> forwarders in the named.conf file. That means having my DNS server 
> configured as a forwarding-only DNS server (recursive mode). Let's say that 
> I have two DNS servers listed in the forwarders statement in the named.conf 
> file.
> 
> How does this algorithm work? Does it work the same way as when I had my 
> name servers in the db.cache file? Will named still query booth DNS servers 
> initially and find out the RTT, and then use the one with the lowest RTT as 
> primary?

BIND 9 doesn't have RTT calculation for forwarders so will query them in 
the order they are specified in named.conf. Not sure if this is in BIND 
9.3 yet? Anyone else know?

It was in BIND 8.2+, and was great for working around failed forwarders, 
but got left out of BIND 9 for some reason. Some people will say you 
shouldn't use forwarders anyway, but in practice many people do.


-- 
Paul Roberts
Senior Consultant
n3k Informatik Ltd.
http://www.n3k.co.uk