intermittent bad horizontal referral?

[Matus UHLAR - fantomas]

On 20.10.11 16:11, Karl Auer wrote:
>Date: Thu, 20 Oct 2011 16:11:03 +1100
>From: Karl Auer <kauer at biplane.com.au>
>To: BIND users <bind-users at isc.org>
>Subject: Re: intermittent bad horizontal referral?
>
>Someone wrote (privately, so I'm not giving a name):
>> There's a bit of problem with the DNS.  You might want to jump over to
>> http://dns.squish.net/ and run an NS traversal for biplane.com.au --
>> pps.com.au's DNS is befuddled.
>
>This is true. Two of the four PPS nameservers do not have glue records
>in .com.au. What I don't understand is how a trace can compete at all,
>if there is no glue.

There are glues for some of pps.com.au servers in com.au zone.
So, some glue records exists, alth0ougn not all that should exist.
However that's enough for the resolution to work.

>If there are no referrals to x.com.au in .com.au, how can a query "jump
>the gap"? Because I can see that happening in a trace. Here are two
>traces for pps.com.au. The first shows referrals in .com.au, the second
>does not. It looks as if n.au somehow answered directly, but g.au did
>not.

n.au seems to handle both .au and .com.au, while s.au (not g.au) only 
handles .au, so it sent referral to com.au servers.

>au.			172800	IN	NS	o.au.
>au.			172800	IN	NS	n.au.
>au.			172800	IN	NS	a.au.
>au.			172800	IN	NS	l.au.
>au.			172800	IN	NS	m.au.
>au.			172800	IN	NS	r.au.
>au.			172800	IN	NS	h.au.
>au.			172800	IN	NS	p.au.
>au.			172800	IN	NS	s.au.
>au.			172800	IN	NS	u.au.
>au.			172800	IN	NS	v.au.
>au.			172800	IN	NS	b.au.
>;; Received 496 bytes from 192.112.36.4#53(g.root-servers.net) in 348 ms
>
>com.au.			172800	IN	NS	q.au.
>com.au.			172800	IN	NS	j.au.
>com.au.			172800	IN	NS	i.au.
>com.au.			172800	IN	NS	h.au.
>com.au.			172800	IN	NS	o.au.
>com.au.			172800	IN	NS	l.au.
>com.au.			172800	IN	NS	g.au.
>com.au.			172800	IN	NS	n.au.
>com.au.			172800	IN	NS	m.au.
>com.au.			172800	IN	NS	p.au.
>com.au.			172800	IN	NS	k.au.
>;; Received 408 bytes from 2607:f140:ffff:fffe::e#53(s.au) in 193 ms
>
>pps.com.au.		14400	IN	NS	ppsdns6.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns4.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns2.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns1.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns3.pps.com.au.
>;; Received 214 bytes from 202.65.12.72#53(i.au) in 16 ms

[deleted]

>au.			172800	IN	NS	b.au.
>au.			172800	IN	NS	r.au.
>au.			172800	IN	NS	a.au.
>au.			172800	IN	NS	o.au.
>au.			172800	IN	NS	p.au.
>au.			172800	IN	NS	v.au.
>au.			172800	IN	NS	l.au.
>au.			172800	IN	NS	m.au.
>au.			172800	IN	NS	n.au.
>au.			172800	IN	NS	h.au.
>au.			172800	IN	NS	s.au.
>au.			172800	IN	NS	u.au.
>;; Received 496 bytes from 2001:dc3::35#53(m.root-servers.net) in 178 ms
>
>pps.com.au.		14400	IN	NS	ppsdns3.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns2.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns4.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns1.pps.com.au.
>pps.com.au.		14400	IN	NS	ppsdns6.pps.com.au.
>;; Received 214 bytes from 69.36.145.34#53(n.au) in 227 ms
-- 
Matus UHLAR - fantomas, uhlar at fantomas.sk ; http://www.fantomas.sk/
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