Re: TTL From Parent or Child Zone?

Sabahattin Gucukoglu <[email protected]> wrote:
> Well yes, but it also makes your cache inaccurate for the case where
> the delegating name server always holds records that dominate the
> authoritative data due to long TTLs.

For a given domain name and record type, dnscache keeps the record
that it received most recently.  So if it's looking up the address of
www.example.com, and the.com servers say that example.com has the name
server a.ns.example.com, with the address 1.2.3.4, dnscache will cache
that - but then once it talks to a.ns.example.com, it will get new
NS/A records for a.ns.example.com, which will replace the previous
records in the cache.  So then those records will expire according to
the TTLs from a.ns.example.com, not the TTLs given by the .com
servers.


paul