On Wed, 2008-04-09 at 12:09 -0400, Siegel, Ellen wrote:
...
bounces(_at_)mipassoc(_dot_)org] On Behalf Of Roland Turner
...
Setting aside questions of whether consensus has already been reached,
and the painful technical details of trying to deal with hierachies of
names rather exact matches with individual domain name, it strikes me
that any reasonable "outsider" will look at a spec that doesn't allow
him to specify in one step (rather than hopefully-correctly attached
to
every single zone entry now and through all future changes) "Acme
Corp's
email is ALL signed, or it's not ours" and wonder what the spec
authors
were thinking.
I think if we go this route we need to 1) be more clear about what is
and isn't supported, and 2) include some explanation of how a subdomain
that wants a different policy (e.g. "unknown" where the parent domain is
"all", or "discardable" if it doesn't send any mail and the parent has
published a weaker practice record).
I think part of Dave's point is that doing a good job of (1) may not be
as straightforward as it seems.
I suspect that he's concerned that, even if it were technically
feasible, it may not be so good an idea as it appears.
Examples for (2) are very important in both directions (creating a
subdomain policy that is a) weaker and b) stronger than that of the
parent domain).
Quite.
I take it that the basic technical constraint is the need to keep the
number of DNS queries to "a few" and, in particular, to establish a
constant bound, rather than, say, permit an adversary to shut down some
DNS infrastructure by sending millions of messages purporting to be from
a.b.c.d.e.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.example.com?
- Roland
--
Roland Turner | Product Manager, RealMail | BoxSentry Pte Ltd
3 Phillip Street, #13-03 Commerce Point, Singapore 048693
Mob: +65 96700022 | Skype: roland.turner | Fax. +65 65365463
roland(_dot_)turner(_at_)boxsentry(_dot_)com | www.boxsentry.com
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