[Pdns-users] Feedback on the recursor 3.0 requested + 3.0.1
bert.hubert at netherlabs.nl
Fri May 5 07:34:56 UTC 2006
On Thu, May 04, 2006 at 06:16:20PM +0100, Stephen Harker wrote:
> ;; ANSWER SECTION:
> noblemarine.co.uk. 10518 IN MX 20
> noblemarine.co.uk. 68 IN MX 10
Stephen, I spent quite some time pondering your setup. RFC 2181 says:
Resource Records also have a time to live (TTL). It is possible for
the RRs in an RRSet to have different TTLs. No uses for this have
been found that cannot be better accomplished in other ways. This
can, however, cause partial replies (not marked "truncated") from a
caching server, where the TTLs for some but not all the RRs in the
RRSet have expired.
Consequently the use of differing TTLs in an RRSet is hereby
deprecated, the TTLs of all RRs in an RRSet must be the same.
So in a sense, you are feeding the internet bad data, and getting bad
results in return, which has an amount of fairness to it.
You are in luck though as the RFC tries to have its cake and eat it too:
Should an authoritative source send such a malformed RRSet, the client
should treat the RRs for all purposes as if all TTLs in the
RRSet had been set to the value of the lowest TTL in the RRSet.
Implemented in http://wiki.powerdns.com/projects/trac/changeset/819
But you should still fix your broken ttls!
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