I take this last updated review and provide some answers inline.
I have updated my review of the -10 version for -11 below.
Comments/suggestions that I do not comment on still apply.
On Wed, May 25, 2022 at 3:41 PM Donald Eastlake <
d3e3e3@xxxxxxxxx> wrote:
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.
Well, minor 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?
This is more of an operational point. If you update a mapping, the best would be to give sufficient time so that everybody updates and there is no such a risk.
What about adding in section 7 “dealing with Map-Version Numbers” the following sentence.
It is an operational question to make sure that Map-Version numbers are not updated so frequently as to create the risk that very old version numbers appear newer (because of the circular space).
Would that address your issue?
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?
Actually section 7.1 reads:
Operators can configure exceptions to this
recommendation, which are outside the scope of this document.
We should have done the same for 7.2, will do in a revision.
Otherwise, the Security Considerations seem adequate although I think the 1st and 2nd paragraphs of Section 8 should be swapped.
Yes, it may read better. Will be swapped in the next revision.
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"?
Wonderful catch. Should be
[69 + 2049; (69 + 4095) mod 4096]
Will fix.
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?
Absolutely right, the sentence should be:
Upon updating the mapping, the RLOC will receive the less and less
traffic because remote LISP sites will request the updated mapping.
After at least one TTL of the mapping is passed, it could be
considered safe to shut down the RLOC gracefully, because all
sites actively using the mapping should have updated
it.
Sounds better?
TYPOS/MINOR
Should the document say anything about mapping changes possibly causing re-ordering?
Not sure what do you mean by “re-ordering”, can you articulate?
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,"
Above fixed in -11.
Section 7.2, first sentence just after point 3: Suggest using "MAY" in "may be more restrictive."
Will be changed in the next revision.
Section A.2.3: "provider edge" pops up here with no other mention or explanation anywhere in the draft.
Either drop the term or provide some sort of definition/explanation.
Provider edge should actually be just “domain"
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".
Yes, is
With this setup, the Proxy-ETR, by looking at the Source Map-Version Number,
is able to check whether the mapping has changed.
EDITORIAL
Section 1: "This operation is two-fold." -> "This information has two uses."
New Section 6: "... MUST consist in an increment ..." -> "... MUST
consist of an increment ..."
New Section A.2.3: "uRPF" is used only once so the acronym should be
dropped and only the expansion used.
Will update as suggested in the next revision.
Thanks again for the review.
Let me know if the proposed changes address your comments.
Ciao
L.
Thanks,
Donald
===============================
Donald E. Eastlake 3rd +1-508-333-2270 (cell)
2386 Panoramic Circle, Apopka, FL 32703 USA
d3e3e3@xxxxxxxxx
