Re: [Sidrops] Genart last call review of draft-ietf-sidrops-ov-egress-01

[Randy Bush <[e-mail]>]

( warning: quote depth errors and top posting.  keyur's mta, well let's
not get into that :)

> Speaking as a wg member.

and one of the first ROV implementors, tyvm.

> Shouldn’t you be checking the "my autonomous system number" in the
> update message (when sending it out to the ebgp peer) as opposed to
> "my autonomous system number" in the open message.
>
> Regards, Keyur
>
> On 3/17/20, 8:27 PM, "Randy Bush" <[e-mail]> wrote:
>
>> I wanted to avoid "be able to be" and have an explicit actor. I see
>> the difficulty you point to below.
>
> i am happy to change to the following
>
>>> As the origin AS may be modified by outbound policy, a BGP speaker
>>> MUST apply ROV policy semantics using the My Autonomous System number
>>> in the BGP OPEN message (see RFC 4271 section 4.2) issued to the peer
>>> to which the UPDATE is being sent.
>
> but, in my free opinion, as it is in IETF LC, the change is enough that
> it might require approval by chairs and/or AD.

i think you're right.  what counts for ROV is the origin AS in the
UPDATE.  open a hole to deviate from that and ...

and we have to remember that, for these UPDATEs which are redistributed
into BGP by this speaker, have their AS_PATH first created when sent to
the peer.  i.e. we can not (yet) speak of the origin AS in the AS_PATH.

so maybe

    As the origin AS of a BGP UPDATE is decided by configuration and
    outbound policy of the BGP speaker, a validating BGP speaker MUST
    apply Route Origin Validation policy semantics against the origin
    Autonomous System number which it will put in the AS_PATH (see RFC
    4271 4.3 Path Attributes:b) of the UPDATE to the peer.

randy