Sriram,
> On Jul 19, 2022, at 4:52 PM, Sriram, Kotikalapudi (Fed) > <[email protected]> wrote: > >> Since there's work to simply make "sets go away" (which I owe you text for), >> there are two choices: >> 1. Make the text correct for as-sets, which will complicate the algorithm >> (but perhaps not significantly) >> 2. Preclude sets as valid matches for aspa purposes and keep the simpler >> fully indexed solution. > > The algorithm currently does #1 (relying on non-standard use of 'Segment'). > But we have a way to do #1 even by simply indexing the ASes in the > AS_SEQUENCEs. We can accommodate AS_SET at the beginning of the AS_PATH. We > will accommodate it. What about AS_SET in the middle is my next question. > Please see my other post with the subject: 'Any credence to AS_SET in the > *middle* between AS_SEQUENCEs?' If by "beginning of the AS_PATH", you mean rightmost and toward the origin AS, that's good to hear. I suspect you can have clean procedure for that circumstance. "AS_SET in the middle" is not impossible, but extremely unlikely to be seen. This corresponds to the "complex aggregation" case discussed in RFC 4271's appendices. My personal experience is that this is not typically implemented. That said, it has been seen in the wild on occasion, so someone's implementation is trying to do Something Clever. My personal suggestion is to not worry about accommodating it unless you think it doesn't overly complicate the procedures or impact correctness for the core use case. >> ASPA verification doesn't try to operate on confederation segment types... > > We are thinking we'll add the following statement in the draft about > Confederations: > > The ASes on the boundary of an AS Confederation MUST register ASPAs using the > Confederation’s global ASN and the procedures for ASPA-based AS path > validation in this document are NOT RECOMMENDED for use on eBGP links > internal to the Confederation. I'd support that text. -- Jeff _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
