Re: [DNSOP] I-D Action: draft-ietf-dnsop-glue-is-not-optional-02.txt

[Mark Andrews <[e-mail]>]

John,
	take the following delegations in the parent zone example.

	foo.example NS ns.bar.example
	ns.foo.example AAAA 2001:0DB8:0000:000b::1

	bar.example NS ns.foo.example
	ns.bar.example AAAA 2001:0DB8:0000:000b::2

If you don’t return sibling glue a query for b.foo.example returns
a referral of


	foo.example NS ns.bar.example

and a query for ns.bar.example returns a referral of 

	bar.example NS ns.foo.example

and the subsequent query for ns.foo.example  returns a referral of

	foo.example NS ns.bar.example

Returning sibling glue is not an optimisation.

> On 28 Jul 2021, at 10:47, John R Levine <[e-mail]> wrote:
> 
>>>> Just to make sure we're talking about the same thing, the definition of
>>>> sibling glue is glue from another zone delegated from the same parent.
>>> 
>>> That's not what the example in 4.1 of the draft shows.  It has foo.test
>>> depending on ns1.bar.test, so the server adds the A record for
>>> ns1.bar.test.
>> 
>> It does actually.
> 
> Oh, sorry, I misread your message.
> 
>> "ns1.bar.test/A" is glue for "bar.test" (and sibling glue for "foo.test" in that
>> example). It is returned by the servers for "test" in a referral for "foo.test".
>> 
>> Open to suggestions for more clarifying language.
> 
> Unless I'm misunderstanding something, in the absence of sibling glue, the resolver would make a second request for ns1.bar.test, same as if it were ns1.bar.otherdomain, and it would get back a referral with the glue.  It is just a performance tweak and I don't see why we should describe it as more than that.
> 
> Regards,
> John Levine, [e-mail], Taughannock Networks, Trumansburg NY
> Please consider the environment before reading this e-mail. https://jl.ly
> 
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Mark Andrews, ISC
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