[ - last-call for clutter ] On Thu, Apr 22, 2021 at 7:11 AM Eric Vyncke (evyncke) <evyn...@cisco.com> wrote:
> Thank you Tim for the re-check of the document. > Indeed, thank you Tim, both for the review, and for being flexible. This document has a long and storied history, and, while it certainly could be better, I think that it's one of those "it's better to ship something imperfect now, vs never getting around to shipping it" type document. W > > Regards > > -éric > > -----Original Message----- > From: Tim Chown <tim.ch...@jisc.ac.uk> > Date: Thursday, 22 April 2021 at 12:55 > To: Eric Vyncke <evyn...@cisco.com> > Cc: Warren Kumari <war...@kumari.net>, Enno Rey <e...@ernw.de>, ops-dir < > ops-...@ietf.org>, "last-c...@ietf.org" <last-c...@ietf.org>, opsec wg > mailing list <opsec@ietf.org>, "draft-ietf-opsec-v6....@ietf.org" < > draft-ietf-opsec-v6....@ietf.org> > Subject: Re: [OPSEC] Opsdir last call review of draft-ietf-opsec-v6-25 > Resent-From: <alias-boun...@ietf.org> > Resent-To: Eric Vyncke <evyn...@cisco.com>, Kiran Kumar Chittimaneni < > kk.chittiman...@gmail.com>, Merike Kaeo <mer...@doubleshotsecurity.com>, < > e...@ernw.de>, <furr...@gmail.com>, Ron Bonica <rbon...@juniper.net>, < > war...@kumari.net>, <rwil...@cisco.com>, Gyan Mishra < > hayabusa...@gmail.com>, <hayabusa...@gmail.com> > Resent-Date: Thursday, 22 April 2021 at 12:55 > > Hi, > > I’ve checked through -26 and compared as best as I can to -25, and > submitted the review. > > I’m happy enough to put a ‘Ready’ tag on it. It could always be > better, but at 50 pages, I fully understand why shipping it is desirable. > I can’t see anything specifically wrong in the text :) > > Tim > > > On 21 Apr 2021, at 19:36, Eric Vyncke (evyncke) <evyn...@cisco.com> > wrote: > > > > Tim, Warren, > > > > Replying with only the author hat (and after consultation with my > co-authors) on this email after having read Warren's and Tim's replies. > > > > Tim, I do not know whether you remember all the painful journey of > this document but the authors do :-) > > > > a) the early versions of the I-D included a lot of 'recommendation' > wording but the OPSEC WG requested us to remove them (this is also the > reason why it is not a BCP) > > > > b) getting a summary would be a nice idea but, again, to reach the > WG consensus, we had to make some recommendation with restrictions and > caveats for special cases (e.g., remember the ULA, RA-guard discussions > ?)... hence, I do not think that this is possibly to make a short summary > without including the restrictions/specifics ... so the summary list will > be very very long and not very useful > > > > All the other last call comments and the IESG COMMENT points will > be addressed once all feedback is collected, by either updating the text > or explaining our points of view on the comment. > > > > Thank you again for your review and the discussion > > > > Regards > > > > -éric > > > > -----Original Message----- > > From: Tim Chown <tim.ch...@jisc.ac.uk> > > Date: Wednesday, 21 April 2021 at 15:41 > > To: Warren Kumari <war...@kumari.net> > > Cc: Enno Rey <e...@ernw.de>, ops-dir <ops-...@ietf.org>, " > last-c...@ietf.org" <last-c...@ietf.org>, opsec wg mailing list < > opsec@ietf.org>, "draft-ietf-opsec-v6....@ietf.org" < > draft-ietf-opsec-v6....@ietf.org> > > Subject: Re: [OPSEC] Opsdir last call review of > draft-ietf-opsec-v6-25 > > Resent-From: <alias-boun...@ietf.org> > > Resent-To: Eric Vyncke <evyn...@cisco.com>, Kiran Kumar > Chittimaneni <kk.chittiman...@gmail.com>, Merike Kaeo < > mer...@doubleshotsecurity.com>, <e...@ernw.de>, <furr...@gmail.com>, Ron > Bonica <rbon...@juniper.net>, <rwil...@cisco.com>, <war...@kumari.net>, > Gyan Mishra <hayabusa...@gmail.com>, <hayabusa...@gmail.com> > > Resent-Date: Wednesday, 21 April 2021 at 15:41 > > > > Hi, > > > > I’ve not yet seen any comments as proposed by Warren, and the > review is due (the deadline was a shorter than usual one). I can go ahead > and look to determine the changes from the diff view. > > > > A fairly main point was whether any summary recommendations would > be added, given the document’s length, and the variation in style through > the document, with some sections having recommendations subsections, others > not. There is a lot of good advice in the text, but it’s a long read as > is, and there’s likely a couple of pages of key bullet points that could be > added. > > > > When is the draft coming back to the IESG? > > > > Tim > > > >> On 13 Apr 2021, at 21:59, Warren Kumari <war...@kumari.net> wrote: > >> > >> Just a quick note to say thanks to Tim for the excellent and > detailed review, and to the authors for addressing it... > >> > >> I took a quick skim through the diffs, and it was a little tricky > for me to tel which all of the comments had been addressed -- authors, if > you get a chance, could you reply noting which comments were folded into > -26? > >> W > >> > >> On Sat, Apr 10, 2021 at 2:46 PM Enno Rey <e...@ernw.de> wrote: > >> Hi Tim, > >> > >> thanks so much for another detailed look at the draft. > >> Your feeling that it has been in the making for a while is correct > (tell me about it ;-), still we think that the operational security > guidance for IPv6 hasn't change much over time, and it might even be more > needed than ever (given current momentum of IPv6 uptake). > >> I went through your below points, and for many of them I've > performed according clarifications/enhancements of the draft. A new version > has then been uploaded. > >> > >> Wish you a great weekend > >> > >> Enno > >> > >> > >> > >> > >> On Wed, Apr 07, 2021 at 02:12:37AM -0700, Tim Chown via Datatracker > wrote: > >>> Reviewer: Tim Chown > >>> Review result: Has Issues > >>> > >>> Hi, > >>> > >>> I have reviewed this document (draft-ietf-opsec-v6-25) as part of > the > >>> Operational directorate's ongoing effort to review all IETF > documents being > >>> processed by the IESG.?? These comments were written with the > intent of > >>> improving the operational aspects of the IETF drafts. Comments > that are not > >>> addressed in last call may be included in AD reviews during the > IESG review.?? > >>> Document editors and WG chairs should treat these comments just > like any other > >>> last call comments. > >>> > >>> This draft analyses operational security issues related to the > deployment of > >>> IPv6, and describes appropriate mechanisms and practices to > mitigate potential > >>> threats. > >>> > >>> I had previously reviewed the draft as an OPS-DIR Early Review in > July 2018, > >>> and again since then, so am familiar with the document and its > history. > >>> > >>> General comments: > >>> > >>> The document has evolved over time with many topics added, and has > an > >>> inevitable ???Frankenstein??? feel to it. The document would be > much better for a > >>> rewrite, but that would be significant work, and would delay > publication > >>> further. The material in the document is good, and the advice is > valuable, so > >>> the focus should be on publishing it sooner rather than later, and > thus the > >>> issues with structure are probably best overlooked. > >>> > >>> An example of the historical evolution of the document are the > instances where > >>> the same topic os covered multiple times. This would ideally be > avoided. > >>> > >>> The section most in need of attention is 2.1, where many aspects > of addressing > >>> are weaved together: allocations, assignments, assignment to > hosts, ULAs, > >>> stable and temporary addresses, etc. This might be better > presented as a > >>> section listing addressing related security issues, such as > privacy for users, > >>> first hop security, network manageability, implications of > multi-addressed > >>> hosts, address accountability (which isn???t mentioned here?), > avoiding > >>> renumbering (if that is security?), etc. > >>> > >>> There are also some sections which summarise recommendations, or > reinforce > >>> them, and others that do not. For a document of over 50 pages, > which is quite > >>> a long read, it would be desirable to have a summary of the key > >>> recommendations, either at the end of each 2nd level topic, or as > a standalone > >>> section at the end of the document where the key points of each > 2nd level topic > >>> are summarised. > >>> > >>> Is it worth citing examples of security toolkits readers can > explore, like the > >>> THC kit, SI6 Networks, etc, maybe Scapy? > >>> > >>> Specific comments: > >>> > >>> p.3 > >>> I don???t understand why NPTv6 is mentioned here, this early. > Just say that some > >>> security issues have IPv4 equivalents, like ND attacks and ARP > attacks, and > >>> some do not, like IPv6 EHs or hop by hop DoS. The NAT discussion > should be in > >>> a standalone section, and be neutral there. > >>> > >>> p.4 > >>> Why mention the specific example of multi-homed networks? What > do you mean by > >>> the exception? Is it that multi-homing is out of scope, and so > are unmanaged > >>> networks? > >>> > >>> p.4 > >>> Again, NPTv6 is mentioned. This section is titled ???addressing > architecture??? > >>> but this bit of text is about reasons for going PA, PI, or > becoming an LIR, > >>> which is not architecture. > >>> > >>> p.4 > >>> In the 7934 para, RFC8981 should be mentioned as it???s a > significant reason of > >>> devices having more addresses. > >>> > >>> p.5 > >>> ULAs are also useful where the prefix changes, for stable internal > addressing > >>> as the global prefix changes? Typically in residential networks. > >>> > >>> p.5 > >>> Section 2.1.4 is really about choices in address assignment within > a network. > >>> > >>> p.6 > >>> Some of these paras should be in a section about IPv6 network > reconnaissance, > >>> how to best mitigate against scanning, and how to inventory your > own network > >>> elements. > >>> > >>> p.6 > >>> All mentions of 4941 should be replaced with 8981. > >>> > >>> p.7 > >>> Can use 7721 and 8981 together. > >>> > >>> p.7 > >>> Why are DHCP and DNS limped together? The DNS is only about > DNSSEC, so call it > >>> that? > >>> > >>> p.7 > >>> ???Even if the use of DHCP??? - this reads badly. Rather 8504 > talks about this in > >>> 6.5, where RFC7844 is mentioned for example. This should be in a > user privacy > >>> section (if this document had one). Section 8.4 is also useful > advice. > >>> > >>> p.8 > >>> The first para is very muddled. > >>> > >>> p.8 > >>> In 2.1.7 this can also be useful for ACL controls, if one admin / > control > >>> system sits in a prefix of its own. > >>> > >>> p.10 > >>> This is really about handling of fragmented packets (the topic) > not the > >>> fragment header itself Also this is covered in 2.3.2.1 as well. > >>> > >>> p.10 > >>> In 2.2, the intro can say these issues have parallels in IPv4. > >>> > >>> p.11 > >>> First line, say the attack can typically happen from a large > address scan if > >>> permitted into the network? > >>> > >>> p.11 > >>> Bullet 1 - that contradicts the comments on predictable addressing. > >>> Bullet 2 - how? Some clues here would be useful. > >>> > >>> p.12 > >>> ???Current??? - really? All current implementations? Delete > ???current??? or replace > >>> with ???naive??? maybe. > >>> > >>> p.12 > >>> ???Communicate directly??? - at L2? If so, why? > >>> > >>> p.12 > >>> An example of a recommendations section here, where other sections > with advice > >>> are not titled as such. See the General comment on this. > >>> > >>> p.13 > >>> ???Trivial??? cases - aren???t these common ones, like edge > switches in an enterprise? > >>> > >>> p.13 > >>> Why ???hostile???? Delete? > >>> > >>> p.14 > >>> In 2.3.5 last para, what about mDNS, Bonjour? Though the DNS SD > work is now > >>> on unicast discovery. > >>> > >>> p.21 > >>> Maybe add here 802.1x as an example of the value of RADIUS logs, > and add in > >>> here as bullets info harvested from switches and (say) router NDP > syslog > >>> (though that???s I suppose the 4th bullet). These are mentioned > in 2.6.1.7 but > >>> should be split out at the same level as the other topics here. > >>> > >>> p.28 > >>> The text is 2.6.2.2 repeats earlier text. > >>> Similarly text in 2.6.2.3 is repeated form before. > >>> > >>> p.29 > >>> In 2.6.2.4 presumably also a rapid growth in ND cache size is an > indicator. > >>> > >>> p.29 > >>> In 2.7 point to RFC 4942 > >>> > >>> p.30 > >>> Should RFC 6092 be mentioned here? > >>> And that the best defence against IPv6 attacks n ???IPv4 only??? > networks is to > >>> deploy and manage IPv6? > >>> > >>> p.31 > >>> First bullet on this page - but isn???t this the same as if the > traffic is not > >>> tunnelled? Why does tunnelling add the requirement? The same > applies on the > >>> first para on p.32 > >>> > >>> p.31 > >>> Maybe say here the mitigations can also break tunnel brokers > (might be desired, > >>> but users will notice???)???. Maybe tunnels to specific brokers > can be allowed. > >>> > >>> p.32 > >>> ISATAP, in 2021? Same with 6rd. General advice should be deploy > native, avoid > >>> tunnels. > >>> > >>> p.33 > >>> Same for 6to4. > >>> > >>> p.34 > >>> Teredo though, is that still included in Windows and XBoX, as a MS > thing? > >>> > >>> p.36 > >>> Maybe cite Geoff Huston???s blog on this - it???s very good. > Maybe there???s a more > >>> recent update though - > >>> https://blog.apnic.net/2016/06/09/lets-talk-ipv6-dns64-dnssec/. > Host CLAT is > >>> applicable here? (Hence a site should support the 64PREF RA > option? RFC8781 > >>> > >>> p.38 > >>> In 2.8, to be fair IPv4 is also hardened a lot of late due to the > prevalence of > >>> use of devices in WiFi hotspots etc. > >>> > >>> p.37 > >>> Also RFC6092 on section 3.1? > >>> > >>> p.38 > >>> ???Where RFC1918 address are often used??? - add ???often???, the > text implies all > >>> enterprises use v4 NAT. > >>> > >>> p.41 > >>> Only 2 normative references? > >>> > >>> Nits: > >>> > >>> p.1 > >>> ???The Internet??? - you probably mean ???an ISP network??? > >>> ???Describes the security??? - delete ???the??? > >>> > >>> p.4 > >>> ???Which are the switch??? delete ???which are??? > >>> > >>> p.8 > >>> Varying -> various > >>> > >>> p.10 > >>> ipv6 -> IPv6 > >>> > >>> p.18 > >>> Router processor - add r to ???route??? > >>> > >>> ??? > >>> Tim > >>> > >>> > >>> _______________________________________________ > >>> OPSEC mailing list > >>> OPSEC@ietf.org > >>> https://www.ietf.org/mailman/listinfo/opsec > >> > >> -- > >> Enno Rey > >> > >> Cell: +49 173 6745902 > >> Twitter: @Enno_Insinuator > >> > >> > >> -- > >> The computing scientist’s main challenge is not to get confused by > the > >> complexities of his own making. > >> -- E. W. Dijkstra > > > > > > > -- The computing scientist’s main challenge is not to get confused by the complexities of his own making. -- E. W. Dijkstra
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