I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments.

From the introduction, “This specification Extends [RFC8505] and [RFC9010] to add the capability for the 6LN to subscribe anycast and multicast addresses and for the 6LR to inject them in RPL when appropriate.” 

I want to start by saying that I have little experience with the protocols described in 8505 and 9010; I’d suggest that the AD have my security-related comments double-checked with someone who has both security expertise and expertise in these protocols.

As a general comment, it took me several passes to make sense of the introduction. It seems to aim toward explaining the gaps motivating this RFC, along with the building blocks this document uses to fill those gaps. It might help readers to explain this from the outset, and to explicitly call out which is which. There are still some paragraphs/sentences there whose purpose I don’t understand.

For the security considerations, I have 2 suggestions: first, it currently calls out the “security section” of RFC 8505. Shouldn’t it also call out the security considerations of RFC 9010? Second (and I’m not sure about this), does this extension potentially permit any new bad behavior (distinct from 8505 and 9010) that should be called out? I don’t understand the protocol nuances well enough to say, but I’d have felt more certain if it said so explicitly.