how work delegation zone

[Kevin Darcy]

HALLAF D ext OCISI wrote:

> hello,
>
> I'm novice in DNS, and i really need your help.
> I have some problem to understand how work the delegation zone.
>
> I use 2 servers for a delegation zone:
>         sam.org IN      NS      ns1.sam.org
>         sam.org IN      NS      ns2.sam.org
>
> The servers ns1 and ns2 have the record record.sam.org.
>
> How work my name server if a client want to know the IP adresse of =
> record.sam.org.

If the resolver has nothing cached, then it'll start at the root servers
and works its way down the delegation tree, i.e. "." (root), "org",
"sam.org", and then, if necessary, "record.sam.org". If the resolver has
information already cached, then it can omit some or all of those steps.

> Who is the server (ns1 or ns2) answer of my name server?

When resolvers talk to nameservers, they typically keep track of how
quickly each nameserver responds, and will prefer faster ones over
slower ones. Less sophisticated resolvers may simply spread their
queries equally and/or randomly over all of the nameservers for a
particular zone.


- Kevin