Re: [DNSOP] Fwd: New Version Notification for draft-bellis-dnsop-edns-tags-00.txt

[神明達哉 <[e-mail]>]

At Fri, 8 Mar 2019 12:03:27 -0500 (EST),
Paul Wouters <[e-mail]> wrote:

> [my last email in this thread. I don't think we are progressing and I'd
>   like to give others a chance to participate in this thread. But feel
>   free to reply]
>
> >>  But assigned and left completely opague is not really suitable for
> >>  "heterogenous off-the-shelf software". These different vendors must
> >>  understand the meaning of the opaque data even if their functionality
> >>  can be non-standard.
> >
> > No, it does *not* require that at all.
>
> Unless the implementations just log these numbers, they are expected to
> do or trigger something. Either with their own interpretation, or by
> some helper process or configuration magic interpreting these things for
them.

+1.  It's very difficult for me to imagine how we can expect that two
"heterogenous off-the-shelf software" products can be interoperable
just because we have a standardized EDNS option code for opaque tags.

For example, assume that an operator uses dnsdist as a DNS load
balancer and BIND 9 as backend servers with RRL, and the operator
wants to trust particular clients (identified by their IP addresses)
and bypass RRL for them.  How can we expect off-the-shelf dnsdist and
off-the-shelf BIND 9 support this operation with the only assumption
being that both of them support edns-tags?  Is there an implicit
assumption that:
- this version of off-the-shelf dnsdist happens to have a new
  configuration option so it will add an edns-tag with setting bit X
  when the client IP address matches a specified set of address list,
- this version of off-the-shelf BIND 9 happens to have a new
  configuration option to skip RRL if an incoming request contains an
  edns-tag option with bit X on
?

At this moment I don't have a strong opinion on the proposal itself,
but the "off-the-shelf software" argument doesn't sound very
convincing or realistic.  Perhaps I miss some implicit assumptions, in
which case I'd like the draft to explain these in more detail.

--
JINMEI, Tatuya