[dns-operations] imdb.com (i.media-imdb.com (iwi.media-imdb.com))

bert hubert bert.hubert at netherlabs.nl
Mon Mar 7 21:40:40 UTC 2011


On Mon, Mar 07, 2011 at 10:04:10PM +0100, bert hubert wrote:
> I don't see anything particularly odd, except for the length of this CNAME
> chain.  It may be that the 20 second and 60 second TTLs cause some
> 'resonance' for some resolvers.

Ok, this one is surpassingly odd. Anyone from Amazon here?

Compare dig -t a iwi.media-imdb.com @ns-912.amazon.com +norecurs
(gives a CNAME)

to

dig -t any iwi.media-imdb.com @ns-912.amazon.com +norecurs
(gives a 1 second SOA, plus a sideways NS referral, PLUS 6 additional bytes
trailing the packet, and no CNAME).

It may be that Bob's resolver is doing ANY queries instead of A queries, a
trick which is sometimes used to grab A and AAAA records at the same time.

The trailing six bytes consist of a compressed label, but nothing else.

Smells like another broken load balancer.

	Bert


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