Last Call Review of draft-ietf-lisp-6834bis-10
review-ietf-lisp-6834bis-10-secdir-lc-eastlake-2022-05-27-00

I have reviewed this document as part of the security directorate's ongoing
effort to review all IETF documents being processed by the IESG.  Document
editors and WG chairs should treat these comments just like any other last
call comments. Sorry this is a bit late.

The summary of the review is Ready with Issues.

This Standards Track draft on "Locator/ID Separation Protocol (LISP)
Map-Versioning" obsoles the previous Experimental RFC 6834. I have not been
following LISP but I read draft-ietf-list-introduction before reviewing
this draft so I think I understand what's going on.


SECURITY

This draft appears to completely ignore the issue of Map Version Number
advancing so far so quickly that an old version number is encountered that
appears to be newer than or equal to the current version number. Why can't
this happen? Or if it can, why doesn't that hurt?

Section 8, last paragraph: Says Map-Versioning can only be used in trusted,
closed environments but Section 7.1 and 7.2 seem to talk about what to do
about the Map-Version field without any reference to this, but mentioning
private deployments for certain error conditions. For example, Section 7.2
point 3 says to discard a packet on an erroneous Map-Version value except
perhaps in some private deployments. But if you MUST NOT use Map-Versioning
on the open internet, shouldn't it be required to discard all LISP
encapsulated packets with Map-Version numbering if received over the public
Internet?

Otherwise, the Security Considerations seem adequate although I think the
1st and 2nd paragraphs of Section 8 should be swapped.


OTHER ISSUES

Section 6, right after equation 3: Isn't "(69 + 4096) mod 4096" the same as
"69"? And isn't 69 equal to 69, not less than 69? Shouldn't it say
"Map-Version numbers in the range [69 + 2049; 68] are smaller than 69"? Or
actually "in the ranges [69 + 2049; 4095] and [1;68] are smaller than 69"?

Section A.3: How is it possible to tell that no more traffic will be
received? Should this instead be something like wait the TTL of the
mappings to that RLOC plus estimated transit time and some margin for
safety?


TYPOS/MINOR

Should the document say anything about mapping changes possibly causing
re-ordering?

Section 1: I think the following should end with "ITR": "If this is not the
case, the ETR can directly send a Map-Request containing the updated
mapping to the ETR,"

Section 7.2, first sentence after point 3: Suggest using "MAY" in "may be
more restrictive."

Section A.2.3: "provider edge" pops up here with no other mention or
explanation anywhere in the draft

Section A.2.3: The last two sentences sound like they contradict each
other. I assume the last sentence is refering to change in the Source
mapping. Suggest "the mapping" -> "the Source mapping".


EDITORIAL

Section 1: "This operation is two-fold." -> "This information has two uses."


Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 2386 Panoramic Circle, Apopka, FL 32703 USA
 d3e3e3@gmail.com