DNS reply ADDITIONAL SECTION data with MX lookup ?

[Mark Andrews]

> 
> quoting Brad Knowles:
> 
> > 	Hmm.  So, if one of the A RRs for a name has a lower TTL and then 
> > gets aged out, all the other A RRs for that same name get thrown away 
> > at the same time?  Interesting.
> 
> it's slightly different. See ttlcheck() and rrsetupdate() in ns_resp.c [8.2.2
> ].
> 
> -Peter

	Actually what Brad said is correct.  Named discards the whole RRset
	when any RR expires.

	ttlcheck is used to workout if we will accept a particular RRset or
	not based on TTL consistancy.

	We don't normalise differing ttls except on loading a master zone.
	I am aware that this is not strict RFC 2181.  However we also
	consider any case where a RRset is not all discarded at the same
	time to be a bug.

	Mark
--
Mark Andrews, Nominum Inc.
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at nominum.com