This is an appeal to the IAB against the IESG decision to reject my appeal against their earlier decision to approve the publication of draft-ietf-ipngwg-addr-arch-v3-11.txt as a Draft Standard. The issues here are very simple, and no lengthy examination of mailing list archives, taking of evidence, hearing opinions, ... should be necessary in this case. I believe that none of the facts are in any kind of dispute. Those facts are 1) RFC2026 says, in section 4.1.2 ... A specification from which at least two independent and interoperable implementations from different code bases have been developed, and for which sufficient successful operational experience has been obtained, may be elevated to the "Draft Standard" level. [...] The requirement for at least two independent and interoperable implementations applies to all of the options and features of the specification. In cases in which one or more options or features have not been demonstrated in at least two interoperable implementations, the specification may advance to the Draft Standard level only if those options or features are removed. 2) draft-ietf-ipngwg-addr-arch-v3-11.txt contains at least one (and perhaps two) features for which there are not two interoperable implementations. The one is: For all unicast addresses, except those that start with binary value 000, Interface IDs are required to be 64 bits long and to be constructed in Modified EUI-64 format. There's no dispute that there are no interoperable implementations of this - there are no implementations of it at all (or no documented ones anyway). Note that the spec actually gives no option here, other than the exceptions (the 000 addresses, and multicast), interface IDs are required to be 64 bits long. While all implementations I'm aware of allow 64 bit IDs, none have been presented that require it. The draft *requires* it. Any reasonable reading of 2026 would require that that feature of the specification be removed from the draft before the draft is permitted to be published as a draft standard. Of course, as an alternative, the WG or IESG could have the draft, as it is, published as a Proposed Standard, and await the necessary two implementations of the feature before requesting advancement. The IESG's opinion of this seems to be that the "two implementations of every feature" applies only where they consider it important enough to bother checking. I have no problems with drafts advancing when no-one brings to the attention of the IESG that there is a problem in this area. But when a problem is pointed out, the clear words of 2026 really must be enforced. The rationale for this requirement in 2026 is simple (as the IESG should know, as the author of 2026 is a member of the IESG). First, it ensures that the text in the document is clear enough that it can be implemented in an interoperable way. And second, it helps make sure that the document doesn't get cluttered with requirements in practice no-one bothers to implement - that is, that the document is a proper specification, and anyone reading the document can implement from it, with the expectation that their implementation will interoperate with others. The quoted text from the draft fails both of those tests. We have no implementations so we don't know that the text is clear enough to be implemented correctly. It may seem obvious that the text is clear to any reader - but the IETF has always ignored "seem obvious" and required actual implementation experience as a demonstration. Second, an implementation which did faithfully follow the words of the draft would fail to interoperate correctly with every other known implementation of it. It may be claimed that it is the other implementations, or the way they are configured, that is at fault here, but that's not relevant - the aim is to get interoperability, and if we have operators configuring /112, /226, /227 and similar prefix lengths (that is, interface ID's that are 16, 2, or 1, and other, numbers of bits long) - and we do - then an implementation that enforced the 64 bit IID requirement (allowed only /64 prefix on an interface) would fail to interoperate with other implementations (with all other existing implementations). This seems to be a "placeholder" fluff feature, being maintained to perhaps allow some future design to allow applications to simply "know" what is the prefix, and what is the interface-ID. The requirement for existing implementations in 2026 is a specific requirement that such fluff be removed from docs before they're allowed to advance to DS status. The extra requirement should be removed from the document, and then, if the WG so desires, published as a PS (or Experimental) RFC of its own. If it then becomes accepted and implemented, it could be merged back with the main document in a later revision. The second issue in the appeal to the IESG concerned the 'u' bit, which is one of the bits of the IID as defined. The IESG referred to this as ... B/ Robert says "The requirement that where the 'u' bit (the inverted L bit from the MAC address) is set, the IID is globally unique." and eventually concluded ... The IESG notes that there is no wording in draft-ietf-ipngwg-addr-arch-v3-11.txt requiring that IIDs be globally unique. and then quoted two passages from the draft, only the last part of which is relevant. In the resulting Modified EUI-64 format the "u" bit is set to one (1) to indicate global scope, and it is set to zero (0) to indicate local scope. It is true that the doc does not expressly say "globally unique", what it says is "indicate global scope". The draft also says ... Modified EUI-64 format based Interface identifiers may have global scope when derived from a global token (e.g., IEEE 802 48-bit MAC or IEEE EUI-64 identifiers [EUI64]) or may have local scope [...] And ... The use of the universal/local bit in the Modified EUI-64 format identifier is to allow development of future technology that can take advantage of interface identifiers with global scope. I doubt I'm the only reader to come to the conclusion that "have global scope" actually means "be globally unique". What's more, a review of various IPv6 related mailing lists will show this opinion expressed over and over again. Clearly there are many readers who have leapt to this wrong conclusion, if it is in fact wrong, and as the IESG have concluded, there is no actual expectation that the IID will be any more than probably globally unique, then the draft should probably be more explicit in saying that, rather than allowing readers to leap to the incorrect interpretation. But there is more to this than the IESG apparently understood. The question isn't just whether the 'u' bit being set implies that the IID is globally unique (or has "global scope") but whether there are any implementations at all that actually enforce the setting of the 'u' bit only when the IID has been formed from a (probably) globally unique token (a MAC address or similar). Here there has been one implementation reported on the mailing list (but not in the interoperability report) - but for DS status, one implementation isn't enough. Other implementations allow the user to configure the 'u' bit set without having any knowledge or expectation, or reason to assume, that the address is derived from any kind of globally unique token (or token with global scope). What's more, they do this for good reason, as without that ability, users have no way to remove a NIC, and replace it with another, and retain the original (auto-configured) IPv6 address (which being based upon the MAC address that the old NIC provided, would have had the 'u' bit set). In this case the address is in fact based upon a globally unique token, but the implementation has no way to know that, and so must also allow the 'u' bit to be set when the rest of the IID is 0, or 1, or 2, which are most certainly not tokens with any kind of global scope. What's more, as the old NIC may be now in use in some other host, there's no reason in the example cited to assume that there's any uniqueness at all - for correct IPv6 operation, the NIC can't be connected to the same subnet as where it used to be, but beyond that IPv6 works just fine with the same IID on different nets). Once again, we have a feature of the specification which is either not implemented, or at best, is not clear. The IESG's response to all of this is ... When considering this appeal, it is clear from the interoperability reports that there are implementations that generate the interface ID from the EUI-64 identifier, which makes it be 64 bits long. It is also clear that the uniqueness properties of EUI-64 based identifiers will be the same as the EUI-64 identifiers from which they are derived (which is slightly weaker than a requirement for global uniqueness). Yes - though in practice implementations (bar one) allow addresses to be generated from EUI-64's, but they also allow indistinguishable addresses to be manually configured - so in practice (which is what the interoperable implementation requirement is attempting to ensure that the specification conforms to) extracting an IID from an IPv6 address, and expecting it to have any kind of similar properties of global uniqueness as an EUI-64 would be a false expectation, and the draft should not lead people into expecting otherwise. Only if implementations actually enforced this requirement (which they can easily do, as the one which has done it shows, though of course, this loses functionality) would this expectation be justified. So for at least some implementations, they are capable of acting as specified in the document being challenged. No. The requirement challenged is a "must only be" - or if you like, a MUST NOT. The fact that it is possible to conform with the spec using existing implementations has nothing to do with the issue at all. The IESG's response here would be the equivalent of responding to a requirement that "All cars must be red" by pointing to a few red cars and saying "see, it can be done". That it can be done isn't the issue, the issue is that the specification says it MUST be done. To be advanced to DS, all that is required is that there be 2 conforming implementations, what the rest do is irrelevant (until the doc is ready to be advanced to full standard). For some specifications, 2 implementations itself is a large hurdle, for IPv6, it isn't, there are many implementations. That none of them have implemented one of the requirements of the doc, and only one another, should be a pretty obvious red flag that these requirements should not remain in the document. The IESG also says ... We traditionally require that things interoperate when configured correctly, not that they interoperate when configured incorrectly, or that it be impossible to configure them incorrectly. Of course, that's as it should be. That is, except where the specification explicitly says that something must not be possible. There's no point keeping a prohibition in the specification if no-one takes any notice of it. There's no difference here to keeping some other feature that no-one bothers to implement. And again from the IESG ... Implementation reports are used to verify that independent implementations can succesfully interoperate. This is a quality check on the clarity of the documents. Yes. But the IESG have managed to conveniently forget the other purpose for the requirement - that is, as a check that the features are actually being implemented, and that the document isn't describing things which in practice everyone ignores. But even without that, here we have no quality check on the clarity of the relevant statements in the documents - no-one has implemented them. (No-one has implemented one, there's only one implementation of the other). We're only guessing if we assume that the statements are clear enough. IESG again: Requiring explicit verification on all statements would be a change to existing practice and one that would likely increase the difficulty in advancing documents on the standards track. That's what was intended. If existing practice has been to ignore the two implementation requirement, when it is known not to be met, then I submit that the IESG has been operating contrary to the clear instructions of 2026. It need not be onerous to enforce this however - it is entirely reasonable to expect the community to point out any flaws in the implementation reports as published. If there are no reported problems, the IESG, and the community, are justified in assuming that the reports fully document the required interoperability of every feature. Where there are reports that interoperability of some feature has not been properly documented, then it should be easy for the implementation report to be corrected, if the feature has in fact been implemented and tested. If it has been implemented, but not tested, then the report should be seen as being of benefit, in showing a potential trouble area, not as a burden. If testing shows that all works, then there's real harm done, and the implementation report can be corrected. If testing shows non-interoperability, then clearly there's something that needs fixing (in some cases, just implementation bugs, after which further testing will show the specification is fine). On the other hand if testing is not possible, because the feature has not been implemented, then it really should be removed from the document before it is advanced. That's what the requirement in 2026 is there for. The IESG again ... There are many places in IETF standards where a field is stated to be a specific length or a value to be within a range. Requiring that the limits be enforced in software for all of these cases would put a significant extra burden on the implementers and the documenters of the implementations for questionable benefit. This is once again based upon a misunderstanding of what is required. No-one is requiring that the limits be enforced in general. What is being asked is that someone (sometwo really) has done it. What's the point of a requirement that is universally ignored? There is none, it is misleading, and should not be permitted in a Draft Standard. I would ask that the IAB instruct the IESG to overturn their decision to publish the draft (draft-ietf-ipngwg-addr-arch-v3-11.txt) as a Draft Standard, and at their choice, either publish it as a Proposed Standard, or return it to the working group for amendments that will allow it to be published as a Draft Standard. kre ps: I would also request that the RFC editor continue to defer publication of this draft until the IAB has dealt with this appeal.