local DNS server

[Bruno Wolff III]

On Mon, Dec 11, 2006 at 14:11:20 +1030,
  Tim <ignored_mailbox at yahoo.com.au> wrote:
> On Wed, 2006-12-06 at 12:34 +0200, Dotan Cohen wrote:
> 
> > As I understand it, the first time I go to www.example.com it would
> > have to contact the ISP's DNS servers to find the address, so there is
> > not advantage, but the next time it should be cached. Is this
> > accurate?
> 
> That's true.  The same thing applies to the ISP's DNS servers.  If
> you're looking up addresses that no-one else has, or if it's cached data
> has been purged in the meantime.

If you are running your own cache it can work without contacting your ISP's
name servers except for domains that those servers provide authoritative
information for. The cache would start queries by asking the root servers
for information instead (or using information previously obtained from them
that is still cached).