Benjamin - Responses nline. > -----Original Message----- > From: Benjamin Kaduk <kaduk@xxxxxxx> > Sent: Wednesday, September 26, 2018 2:11 PM > To: Les Ginsberg (ginsberg) <ginsberg@xxxxxxxxx> > Cc: David Waltermire <david.waltermire@xxxxxxxx>; secdir@xxxxxxxx; > lsr@xxxxxxxx; ietf@xxxxxxxx; draft-ietf-isis-segment-routing-msd.all@xxxxxxxx > Subject: Re: Secdir last call review of draft-ietf-isis-segment-routing-msd-16 > > On Wed, Sep 26, 2018 at 08:45:03PM +0000, Les Ginsberg (ginsberg) wrote: > > David - > > > > Thanx for the review. > > A new version of the draft (17) has been published to address your > comments - subject to my responses below. > > Just in time for me to see the updated version for my IESG review; thanks. > > > > -----Original Message----- > > > From: David Waltermire <david.waltermire@xxxxxxxx> > > > Sent: Tuesday, September 25, 2018 12:14 PM > > > To: secdir@xxxxxxxx > > > Cc: lsr@xxxxxxxx; ietf@xxxxxxxx; draft-ietf-isis-segment-routing- > > > msd.all@xxxxxxxx > > > Subject: Secdir last call review of > > > draft-ietf-isis-segment-routing-msd-16 > > > > > > Reviewer: David Waltermire > > > Review result: Has Issues > > > > > > 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. > > > > > > The summary of the review is Ready with (minor) issues > > > > > > My apologies for the late review on this draft. Overall I found this > > > document to be well-written, and concise. > > > > > > General Comments: > > > > > > This document uses a mix of case around RFC2119 language (e.g., MAY > may). > > > You should use text from RFC8174 to indicate that lowercase versions > > > of the keywords are not normative, or adjust the case of the > > > lowercase words to ensure there is no confusion. > > > > > [Les:] Section 1.2 does include the standard boilerplate for RFC > 2119/RFC8174. > > > > I checked all the lower case uses of "may" and they are intentional. > > There was one instance of "should" that I changed to uppercase. > > > > > Minor nit: There is some inconsistency in the use of "MSD-Type" (the > > > value) and "MSD type" (the concept). Suggest cleaning this up. > > > > > [Les:] Done > > > > > Specific comments: > > > > > > Section 1: > > > > > > Para 1: s/to insure/to ensure/ > > > > [Les:] Done. > > > > > > > > Section 4: > > > > > > The last paragraph establishes a requirement on the registration of > > > an MSD Type to define what the absence of a given MSD Type means. > > > This is an important requirement that must be addressed during > > > registration of new MSD Types. IMHO, this requirement should be > > > echoed in the registration information in section 6 to make sure it is not > overlooked. > > > > > [Les:] I disagree. Section 6 is defining exactly what should go into the new > IANA registry. > > The definition of "absence" is something that will have to be provided in > the documents which define new MSD-types, but that will NOT be captured > in the registry so including this in Section 6 isn’t appropriate. > > I think a good way to think about this is as giving guidance to the Experts, that > they should not approve registration requests that fail to provide this > information along with the request. Guidance for the Experts is appropriate > in the IANA Considerations section. > (Also, my understanding is that IANA prefers to have a more explicit > template for new registrations to follow, though I should not try to speak for > them.) > [Les:] The reason we use "experts" is because we know/expect them to be familiar with the documents which define the TLVs (unlike a "general IETF reader" whose familiarity with the subject matter may vary). Repeating what is said in Section 4 in Section 6 only makes sense if you think the "expert" only reads IANA sections. Such a person would not be an expert IMO. :-) Les > > > > > Section 6: > > > > > > The "Base MPLS Imposition MSD" should reference section 5 of this > > > document. > > > > [Les:] Again - Section 6 is defining what will go into the registry. The registry > will reference the document - not a specific section of the document. > > The contents of the "Reference" column for Value 1 can refer to a specific > section of a document, surely? > > > > > > > The registration for "Experimental" should be marked as "Reserved > > > for Experimental Use" or just "Experimental Use" to align with > > > RFC8126. RFC8126 states that "it is not appropriate for documents to > > > select explicit values from registries or ranges with this policy". > > > It might be good to add a note alongside the one on "Designated > > > Experts" indicating that values from this range are not assignable. > > > > > [Les:] I have changed the text to "Experimental Use". > > I think the rest of your comment is addressed by RFC 8126 - which is > referenced. > > > > > The "Interior Gateway Protocol (IGP) Parameters" registry has the > > > "Standards Action" policy assigned. The new "IGP MSD Types" > > > sub-registry does not have the "Standards Action" policy. Was this > > > intentional? If so, this should be explained. This is also confusing > > > since the guidance for expert reviewers in > > > RFC7370 implies that registrations are based on the "RFC Required" > > > or "Standards Action" policies. > > > > > [Les:] IS-IS registries are typically Expert Review. This derives from > considerations related to the liason with ISO JTC 1/SC6 (RFC 3563). > > OSPF registries are typically Standards Action. > > > > As IGP Parameters was defined by draft-ietf-ospf-segment-routing- > extensions, it is Standards Action. > > But as MSD-Types is being defined in an IS-IS draft... > > > > Please learn to live with this. > > It isn’t a significant issue in my view. > > > > > > > > > Section 7: > > > > > > The security considerations in RFC7981 ask that security > > > considerations around the disclosure and modification of this type > > > of information is described in extensions. This has been done, but > > > RFC7981 also asks that an integrity mechanism be provided if there > > > is a high risk resulting from modification of capability > > > information. There is no discussion in the document's security > > > consideration about the nature of risk in this case and why an > > > integrity mechanism is not needed. It seems like false information > > > can be used to cause a denial of service regarding computed paths. > > > This sounds like having this happen could be bad. I am not an expert on > routing protocols, so I am not sure if this is an issue. How bad and likely is > such a risk? > > > > > > > [Les:] The integrity mechanism is (as you point out) discussed in the > Security section of RFC 7981 - which is referenced in the Security Section of > this document. > > The introduction of a new TLV does not alter the integrity mechanism > requirements. > > My read of 7981 is that "there are these existing integrity protection > mechanisms; when the consequences of modification are bad, use them". > So there is not necessarily a need for each TLV to provide its own internal > integrity scheme, as Les notes. > > -Benjamin
