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[Quinn Wood <wood.quinn.s AT gmail.com>]

On Wed, Mar 5, 2014 at 6:26 PM, Coyo <coyo AT darkdna.net> wrote:
> How does delegation work?
>
It's a hierarchy.

Nameservers at X.root-servers.net contain NS records (and needed glue
records for those records) for top level zones, while those
nameservers contain NS records (and again needed glue records for
those records) for their own zone.

This way the root isn't using petabytes of traffic answering queries
for Google. Instead that responsibility (and authority) is delegated
to com., who futher reduces their authority and resource usage by
delegating the google (note that's relative to com.) zone to its
operators.

Hopefully ballpark approximation:
1.) Client: Hey a.root-servers.net. (root authority), can I have A
records for www.google.com.?
2.) a.root-servers.net: I don't know any, but I can tell you what the
NS record is for com.. It's a.gtld-servers.net..
3.) Client: Hey a.root-servers.net., can I have A records for
a.gtld-servers.net.?
(The NS record for net. is a cyclical dependency, so the root has this
information.)
4.) a.root-servers.net: The A record for a.gtld-servers.net. is 192.5.6.30.
5.) Client: Hey a.gtld-servers.net (delegated com authority by root),
can I have A records for www.google.com.?
6.) a.gtld-servers.net: I don't know any, but I can tell you what the
NS record is for google.com.. It's ns1.google.com..
7.) Client: Hey a.gtld-servers.net., can I have A records for ns1.google.com.?
(The NS record for google.com. is a cyclical dependency, so the root
has this information.)
8.) a.gtld-servers.net: The A record for ns1.google.com. is 216.239.32.10.
9.) Client: Hey ns1.google.com. (delegated google authority by com.),
can I have A records for www.google.com.?
10.) ns1.google.com: The A records for www.google.com. are:
     74.125.225.80
     74.125.225.81
     [...]