Kia ora, I'm a recent addition to dnsdir and have been asked to review this draft - this is my first formal IETF review, so apologies in advance if I don't quite hit the right spot in terms of what's looked for here - in particular I'm not sure how calibrated my "Result" status selection is... Review Conclusion: The intent and proposed mechanism the draft seeks to achieve is clear and the proposed high-level architecture of a hidden master is consistent with the overall format of the DNS ecosystem. The proposed implementation of the control channel requires a mode of communication (mutual TLS authentication via DoT) that is not an existing standards, nor specified in this document and therefore appear infeasible to me without further specification taking place. There are a number of other gramatical nits and improvements in wording which are needed to improve the clarity and understandability of the standard Major Issues (aka Not Ready): Mutual TLS and DoT - 3.2 and 4.6 recommend that the HNA and DM secure their control channel communications using mutual TLS and DoT - but DoT is not specified to support mutual authentication. While mutual TLS auth at the underlying TLS layer is clearly viable - how to integrate that at the DNS layer, and whether that is compatible with DoT on the existing port, or would need a further port allocation (and subsequent IANA consideration in 13) would need to be addressed. None of the alternative future protocols listed in 3.2 support mTLS either as far as I am aware. Given the recommendation to use XoT (RFC9103) (which does specify mTLS capability) for the Synchronization channel in 5.1 - I wonder why this protocol has not also been considered for the control channel instead of DoT? As written (recommending DoT with mTLS), I do not believe this standard is implementable. Minor Issues (aka Ready with Issues): 2 and 3.1: DNSSEC Resolver - is the exclusion of unsigned/non-DNSSEC resolvers in the terminology and architecture overview intentional? Section 9 confirms that DNSSEC is not required (only RECOMMENDED), so it is possible that both the public and internal resolvers being used are not DNSSEC capable - therefore it seems strange for the architecture overview and terminology to imply that DNSSEC is required. 3.2: The 4th paragraph begins describing "the main issue", the solution to which is not explained in the paragraph, or in the referenced Section 4.2 (which is DNSSEC/DS specific vs the NS, A, AAAA context of the paragraph). In either case, the semantics of how the DM treats the information it receives from the HNA seems out of place in a section describing and primarily focused on the mechanics of the communication channel itself. I suggest removing or rewriting this 4th paragraph to improve the clarity. 4: I find the format of this section confusing and hard to understand with sections 4.1-4.4 describing the information to be conveyed, but not how it is conveyed, and then the message formats being described in 4.5. I suggest it would be much clearer and more understandable to combine the details in 4.5.x with the earlier sections (e.g. put the AXFR details from 4.5.1 into 4.1, and the DNS update details from 4.5.2/4.5.3 into 4.2 and 4.3. 12: I wonder how protected the HNA actually is and whether more exploration/discussion of the risks invovled is required here - in an IPv4 use-case, the IP for the services published in the Public Homenet Zone is highly likely to be the same IP with an open DNS port for the DM to connect to for XFR, and while the relationship in IPv6 is not as straightforward given the likely use of privacy addressing, etc it's not particularly hard to scan the enclosing /64 or beyond for an address with an open DNS port. Given the HNA is already opening a control connection to the DM, was consideration given to re-using that connection (or a 2nd HNA initiated connection to a different address if there is the need for different servers in the DM implementation between control/sync channesl) to prevent the need for opening any listening port on the HNA WAN addresses at all? Nits (aka Ready with Nits): 1.1: This section is titled Selecting *Names* to Publish, but spends the majority of its words actually discussing the nuances of which *addresses* to publish for the selected names. This section may be more accurately and cleary named to include address selection. 1.3: There is a missing word (scenarios) in the first sentence which I think needs to read: "A number of deployment *scenarios* ... 1.3.1: The example would be simpler and clearly if it just stated that the vendor provisions each device with a TLS key pair and certificate matching the assigned name which are used for mutual authentication. The current discussion of 'proceeding to authentication' is confusing, as it's not a phrase I've encoutered before and implies to me that authentication is not completed using the cert/keys, while the explanation about needing both names/keys for regeneration seems neither necessary or correct (any trusted key can be used to replace itself, whether or not a certificate with name is also present). 1.3.2: I think it would be simpler and clearer if the example focused solely on establishing trust between DOI/HNA via the provision of credentials and omitted the speculation about verification of ownership that may or may not be required, and seems like a very separate concern at a different level of the stack. 2. Clarification of some definitions Registered Homenet Domain: Given there can be multiple Public Homenet Zones, presumably there can also be multiple Registered Homenet Domains which should be stated here for clarity. Public Authoritative Servers: s/for the Homenet Domain/for the Registered Homenet Domain/ - 'Homenet Domain' alone is not a defined term. Homenet Reverse Zone: Why is this not called the 'Public Homenet Reverse Zone'? Given the 'Homenet Zone' is private, and this is considered the reverse for the 'Public Homenet Zone' this seems like a confusing inconsistency. Every other term starting Homenet refers to an internal resource, while the corresponding external resources all start with 'Public' except in this case. So I would expect the Homenet Reverse Zone to be the private zone matching home.arpa containing RFC1918 and IPv6 ULA addresses, etc. 3.1: s/detaille din/detailed in/ - in the final sentence of the first paragraph. 3.1: "The DOI is also responsible for ensuring the DS record has been updated in the parent zone." - This statement is too authoritative, and conflicts with 4.2 which clarifies (correctly) that DS updates in the parent zone are optional. I suggest removing this statement, or correcting it to somethign like "Depending on configuration, the DOI may also be responsible...". 3.2: s/RECOMMENDED to use TLS with mutually authentication/RECOMMENDED to use TLS with mutual authentication/ - in the final sentence of the 2nd paragraph.