Re: [Idr] I-D Action: draft-ietf-idr-deprecate-as-set-confed-set-02.txt

[Jeffrey Haas <[e-mail]>]

Ondrej,

On Mon, Nov 04, 2019 at 10:27:52PM +0100, Ondrej Zajicek wrote:
> On Mon, Nov 04, 2019 at 03:31:58AM +0000, Job Snijders wrote:
> > Dear all,
> > 
> > It appears we now could use some running code that treats AS_SET and
> > AS_CONFED_SET as withdraw, or at least provides a
> > button/flag/knob/policy language hook to make it so!
> 
> Hi
> 
> Just added a patch [*] to BIRD to optionally reject AS_SETs (and AS_CONFED_SETs).
> 
> One thing that is not discussed in the draft is handling of AS_SETs in AS4_PATH.
> It would make sense to also do treat-as-withdraw, but handling of inappropriate
> AS_CONFED_* segments is already different in AS_PATH and AS4_PATH.

This is a very good point.  The related normative updates vs. RFC 4893 are
now required.

This gets to be an intresting bit of code verification since it means that
some implementations may have stripped the 2-byte version of sets and the
4-byte stuff is still present in the AS4_PATH.

Then again, the spec was always incomplete with all of the crazy edge cases
that could happen.

-- Jeff