Sriram,
> On Jul 19, 2022, at 11:47 AM, Sriram, Kotikalapudi (Fed) > <[email protected]> wrote: > > RFC 4271 and RFC 5065 specify using the term ‘Segment’ to denote AS_SEQUENCE, > AS_SET, AS_CONFED_SEQUENCE, or AS_CONFED_SET. The ASPA verification draft > v-09 currently deviates from that and uses ‘Segment’ to refer to an AS in an > AS_SEQUENCE and also to refer to an AS_SET. > > Is such non-standard use objectionable or unadvisable? Objectionable and unadvisable both. > > If affirmative, then possible fixes are: (1) remove any AS_SET from the > AS_PATH for algorithm purposes only and then simply use AS(i) to refer to the > i-th AS in the AS_SEQUENCE(s) (with a slight additional tweak in the > algorithm), or (2) use an alternate term like element or component. "element" is keyword used in RFCs 4271 and 5065, but in the context of a segment type. And yes, figuring out what "element" means in an absolute as-path indexed sense is challenging. Normally it becomes necessary to treat AS_PATH elements first as an indexed array of segments of a type. Within a segment, if it's of type sequence, you can generally talk about an AS element in an indexed fashion. If it's a set type, it's usually a membership operation (X is a member of segment....) 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. ASPA verification doesn't try to operate on confederation segment types, so 2 is likely where this goes. -- Jeff _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
