> Thanks for writing this doc. I plan to recommend its approval, but there > were a couple of things that I think should be fixed for clarity before > issuing the RFC. First, I agree with Peter Yee who did a Gen-ART review > on this document:
Thanks for your comments Jari. See responses inline. > Page 6, Rsvd2 definition: the definition both says "reserved for future > use" >> and then says some types actually use it. That sounds like present > use. >> And to generically say that it should be sent as zero and ignored, but > then >> to give uses (such as Type 2) for it is confusing. I suggest > rethinking >> the wording here. > > The type that seems to differ from the "ignore" advice in Section 3 is > Type 14. Perhaps you can reword somehow, or name the Rsvd2 field to > Flags, and let the Subsections define that as "set to 0 and ignore on > receipt". Or something along those lines? I have suggested (and rewritten) that Rsvd2 be sent as 0 and ignored on receipt throughout. > I also agree with this comment and believe the text should be corrected: > >> Page 6, Length definition: there's mention of a "Reserved" field > that's >> included in the minimum length of 8 bytes that are not part of the > length >> value. Since there are actually Rsvd1 and Rsvd2 fields in the generic >> version of the LCAF and sometimes even Rsvd3 and Rsvd4 fields when > using >> specific Types, it might be better to spell out which reserved fields > (Rsvd1 >> and Rsvd2) are meant here rather than giving the field a summary name > that >> doesn't actually appear in the format. This is also important because > any >> Rsvd3 and Rsvd4 fields are included in the Length field, so using a > generic >> "Reserved" description is ambiguous at best. When the Length field is 0, it means that no more data follows (for the LCAF encoding), however the first 8 bytes of the LCAF are still included in the message. So I am trying to discuss the minimum length of the message (which is 8 bytes). I have fixed the text to refer to Rsvd1 and Rsvd2 instead of “Reserved” since there is nothing labled “Reserved”. > > And this seems like a bug as well: > >> Page 13, RTR RLOC Address definition, 4th sentence: The ability to > determine >> the number of RTRs encoded by looking at the value of the LCAF length >> doesn't seem feasible. 3 IPv4 RTR RLOCs will produce the same LCAF > Length >> as 1 IPv6 RTR RLOC. It is not a bug. The number of addresses encoded can only be determined by parsing each one. And there is no value to include a count since you can compute while parsing (since you have to parse the message to retrieve and store variable length addresses). > ---------------------------------------------------------------------- > COMMENT: > ---------------------------------------------------------------------- > > Subsections under Section 4 treat some of the fields in different ways. > For instance, in most cases the subsections do not indicate anything > about the base fields, but for instance Subsection 4.9 does say something > about Rsvd1 and Rsvd2: > > Rsvd{1,2,3,4}: must be set to zero and ignore on receipt. I will make consistent that Rsvd1 and Rsvd2 fields are described up front and Rsvd3/Rsvd4 in the specific type definitions, since they do not appear in all definitions. > This text was raised as an issue by Peter as well: > > When there are no RTRs > supplied, the RTR fields can be omitted and reflected by the LCAF > length field or an AFI of 0 can be used to indicate zero RTRs > encoded. > > Why are we giving two options? Or is this a > be-conservative-what-you-send-but-liberal-in-what-you-accept situation? Because the message can be truncated (to reduce size of message), or the RTR field can be encoded with an AFI=0 (which means no RTR address follows). Dino _______________________________________________ lisp mailing list lisp@ietf.org https://www.ietf.org/mailman/listinfo/lisp