Re: [IPv6] Second Working Group Last Call for <draft-ietf-6man-rfc6724-update>

[Kyle Rose <[e-mail]>]

This:

Well, if we agree to the MUST (with the usual caveat of any IETF ‘MUST’ for
> an implementor :) then we need to review the rest of the text, which would
> include the default policy table, and the section David contributed.  I
> think you’re right, that proposed default table as is would have to
> change.
>

is part of the reason I'm uneasy with a blanket MUST for known-local.

I would be 100% fine with normative language that essentially says "IF (via
some future proposed mechanism) you learn known-local prefixes and insert
them into your policy table, THEN you may prefer v4/v4 to not-known-local
ULA/ULA; but if you do not, then you must prefer ULA/ULA to v4/v4." My
reasoning is that currently there is no specified mechanism for learning
and managing known-local ULA prefixes; and it will be a long time before
the long tail of stacks respond to yet-to-be-specified network signals for
managing those prefixes; yet, in the absence of such an ecosystem I want
ULA/ULA to take precedence over v4/v4, because under 6724 they are
currently mostly useless, and I want ULA to be useful now¹, not in some
distant future.

Kyle

¹ As it happens to be on glibc deployments, which don't comply with either
3484 or 6724.