Re: [dnsext] Name equivalence: Another no protocol change solution

[Niall O'Reilly <[e-mail]>]

On 13/09/10 14:57, Alex Bligh wrote:
> Well, there is more than one type of multiplicity.
>
> If we are talking about label multiplicity, i.e.
>      a1.b1.c1.d1
> and
>      an.bn.cn.dn
> are equivalent for all values of n, thus creating an O(n^k)
> problem, then DNAME solves this to the extent it is used.

	Unless a subsidiary zone apex (for example, 'c' above
	might be delegated from 'b') needs data other than
	a DNAME.

> If we are talking about problem types similar to what
> I understand the Greek tonos problem to be, we have
> a high "cardinality" within the label, so using case
> of letter to indicate sameness we need
>      abcabcabc
>      ABCABCABC
>      abcABCabc
>      AbCaBcAbC (etc.)
> all to be the same.

	This might be seen as a pathological case of
	label multiplicity, where k=1 and n=2^p.  Examples
	with p as great as 5 seem not to be exceptional.

> No solution I've yet seen apart from
> synthesis based solutions (which could be added to 2) fix
> this

	Thanks for making that explicit.

> as DNS's smallest unit of lookup is the label rather than
> the constituent parts thereof. So what I propose is no
> worse than any of the non-synthesis based protocol solutions,
> and anyone wanting to add synthesis (plus online signing) can
> do so orthogonally to what I propose.

	Fair enough!

	Niall O'Reilly