Re: [DNSOP] WGLC for draft-ietf-dnsop-let-localhost-be-localhost-02

[Paul Vixie <[e-mail]>]

Ted Lemon wrote:
> On Jan 26, 2018, at 2:27 PM, 神明達哉 <[e-mail]
> <mailto:[e-mail]>> wrote:
>> It's not clear to me, and either way I believe the draft should be
>> clearer on these points (see also my latest response to Petr. If the
>> intent of the draft is to prohibit any user customization, it should
>> explicitly say so (with, IMO, some more explanation); if the intent is
>> to allow such customization, I believe we should actually loosen it to
>> SHOULDs).
>
> There was no clear intent at the beginning when this was an individual
> submission, but the discussion on the individual submission and on the
> call for adoption seemed to show a fairly strong consensus that looking
> up localhost using DNS is a significant security vulnerability, so MUST
> is the right language. Of course, I was part of that consensus, so I may
> be biased!

i was outside that consensus at the time, and remain so now. the 
security aspects aren't paramount and aren't clearly identified. this 
change could be made in the style of RFC 1535, referring only to the 
operating system API behaviour and not mentioning on-the-wire DNS 
protocol behaviour at all. to the extent that it does the latter it 
could be a strong recommendation ("SHOULD") and have the same impact.

many operators will ignore this advice no matter how it's phrased, and 
nothing bad will happen to them when they ignore it, and that's "not a 
MUST" by definition. reasons to ignore include: not wanting to give any 
of their customers any reason to call in and say "the internet is down".

the ietf is always at its best when its claims are of the form, "if you 
want to do _this_, here's a way to do it interoperably." can that be done?

-- 
P Vixie