Hi Ben, Thanks for the further review and comments. See below.
Version -08 has been uploaded with the goal of resolving these comments. On Wed, Jan 17, 2018 at 8:48 AM, Ben Niven-Jenkins <[email protected]> wrote: > > Hi Donald, > > Apologies for not responding sooner, I have reviewed the latest version (-07) > and still have a couple of comments, see inline below. I have also included > at the bottom of this email some additional editorial nits I found when > reading -07. I have trimmed previous comment and responses from you that are > now covered in the document. > > On 10 Jan 2018, at 20:05, Donald Eastlake <[email protected]> wrote: > > ... > > On Thu, Oct 26, 2017 at 10:29 PM, Donald Eastlake <[email protected]> wrote: >> >> Hi Ben, >> >> Thanks for your review. It appears that is was not responded to in a >> timely fashion. Apologies on behalf of the authors. >> >> (Your review was of the -02 version. The current version is -05.) >> >> On Sun, Apr 24, 2016 at 4:28 AM, Ben Niven-Jenkins >> <[email protected]> wrote: >> > Hello, >> > >> > I have been selected as the Routing Directorate reviewer for this >> > draft. The Routing Directorate seeks to review all routing or >> > routing-related drafts as they pass through IETF last call and IESG >> > review. The purpose of the review is to provide assistance to the >> > Routing ADs. For more information about the Routing Directorate, >> > please see http://trac.tools.ietf.org/area/rtg/trac/wiki/RtgDir >> > >> > Although these comments are primarily for the use of the Routing >> > ADs, it would be helpful if you could consider them along with any >> > other IETF Last Call comments that you receive, and strive to >> > resolve them through discussion or by updating the draft. >> > >> > >> > Document: draft-ietf-trill-directory-assisted-encap-02.txt >> > Reviewer: Ben Niven-Jenkins >> > Review Date: 21 April 2016 >> > Intended Status: Proposed Standard >> > >> > Summary: >> > I have significant concerns about this document and recommend that >> > the Routing ADs discuss these issues further with the authors. >> >> Hopefully the changes made between the version -02 you reviewed and >> the current -05 have made some improvements and, based on your >> comments and WG LC comments, further improvements can be made. > > > I think the -07 is almost good to go, the only outstanding concern I have is > with regards to the security considerations section, see below. Thanks. >> > Comments: >> > Overall this is not the easiest document to read although some of >> > that might be due to my lack of background in TRILL and its >> > terminology. >> > >> > Major Issues: >> > >> > 1) The document has an Intended Status of Proposed Standard, however >> > it does not contain any RFC2119 keywords and does not seem to make >> > any normative statements about required behaviour which I would have >> > expected in a Proposed Standard. >> >> Well, in version -05 there is at least one keyword instance. >> Furthermore, I don't know that such keywords need to always be used >> when an implementation requirement level is being specified. That >> said, we could see if additional RFC 2119 keywords are warranted. > > I noted this as a flag to the ADs because the lack of RFC2119 key words > seemed unusual to me. If the ADs are happy for this to be proposed standard > then I am happy with it being a proposed standard. OK. >> > 2) Section 4: If I understand correctly the TRILL-EN spoofs the >> > Ingress RBridge edge node's nickname in the source address field of >> > the TRILL header. Is this likely to introduce problems? E.g. if >> > RBridges will accept & forward frames that have their own source >> > address in, does it perpetuate routing loops or present security >> > considerations that the document should discuss? >> >> TRILL goes to great lengths to avoid loops and has a hop count in the >> TRILL header so that, should there be a transient loop, a TRILL packet >> in that loop (i.e., an encapsulated frame) will be discarded. In the >> potentially more dangerous case of multi-destination packets, as >> compared with known unicast, where copies could multiply due to forks >> in the distribution tree, a Reverse Path Forwarding Check is used to >> discard packets that appear to be on the wrong link or when there is >> disagreement about the distribution tree. >> >> Security Considerations should probably say more on this. >> >> > Section 8 on Security Considerations also looks very light on >> > text. If you are allowing TRILL-ENs to spoof RBridge source >> > addresses (which I think you are, see comment above) I think you >> > should have a discussion about that somewhere in the document. >> >> I agree that some further discussion is needed in the Security >> Considerations section. > > I don’t see any discussion on TRILL-ENs spoofing ingress bridge nicknames in > section 7 on security considerations. I see the security consideration > section of the referenced RFC6325 states "RBridges do not prevent nodes from > impersonating other nodes” although RFC6325 doesn’t appear to discuss the > security considerations related to allowing such impersonation. > > I think it would be valuable for the security considerations section of > draft-ietf-trill-directory-assisted-encap to explicitly call out that > TRILL-ENs spoof ingress bridge nicknames and explain why that is not an issue > (the text you use above is sufficient for that purpose IMO). > > I leave it up to you & the chairs/ADs to decide if my suggestion is overkill > and that the existing reference to RFC6325 is sufficient for a reader skilled > in the art of TRILL. A paragraph has been added to the Security Considerations to cover this. >> > Minor Issues: >> > >> > 1) Section 3. I am not sure what Figure 2 is trying to convey and it >> > is not referred to by the main text. Is it required? >> >> Figure 2 is intended to show the header of a pre-encapsulated frame >> going from a TRILL-EN to an edge TRILL switch. If it is retained in >> the draft, there should be clarifying text that references it. > > I still don’t see any reference to figure 2 in the text (or to figure 1 for > that matter). References have been added. >> > However, Section 4 says >> > >> > The TRILL-EN learns this nickname by listening >> > to the TRILL IS-IS Hellos from the Ingress RBridge. >> > >> > which makes me think if the TRILL-EN is running IS-IS for hellos, is >> > pushing the directory such an obstacle? >> >> That text refers to snooping on IS-IS messages, not running IS-IS. > > Ah, I see. IMO explicitly using the term “snooping" rather than “listening” > here (and in section 1) would make this unambiguous. I leave it up to you > whether to make that change or not. "listening" has been changed to "snooping". >> > 4) Section 7 on Manageability Considerations only states that in >> > order for the solution to work requires the availability of a >> > directory service, which seems a bit redundant when the entire >> > document is about "Directory Assisted TRILL Encapsulation”. Is this >> > section required? >> >> I agree that the Manageability Considerations section should have >> some material added concerning configuration or be dropped. > > I see this section now includes "TRILL-EN have the same configuration options > as any pull directory client.” Is there a suitable document you could > informatively reference here that describes/discusses the configuration > options for a pull directory client? A reference to the appropriate section of RFC 8171 has been added. > Minor nit: should the sentence start “TRILL-ENs”? OK. > Other editorial nits I found reading -07: > > Section 3, para 2 says "If a destination is not known to be attached to one > or more RBridge edge nodes”. I struggled to parse this without reading it > multiple times, I think what you mean to say is "If it is not known whether a > destination is attached to one or more RBridge edge nodes”? That seems to be better wording. > Section 3, para 4: s/don’t/doesn’t/ > > Section 3, para 8: s/and perform/and performs/ > > Section 5.1, para 2: s/data frames with TRILL header/data frames with TRILL > headers/ > > Section 7, para 1: s/TRIL-ENs/TRILL-ENs/ The above editorial fixes have been made. Thanks, Donald =============================== Donald E. Eastlake 3rd +1-508-333-2270 (cell) 155 Beaver Street, Milford, MA 01757 USA [email protected] > Regards > Ben _______________________________________________ trill mailing list [email protected] https://www.ietf.org/mailman/listinfo/trill
