Hi Orie, comments below. I will shortly publish a new version with the amendments discussed in this thread.
> On 12 Jul 2024, at 22:50, Orie Steele <orie@transmute.industries> wrote: > > Gavin, thanks for your comments. > > Nothing major or blocking here, but still some clarifying questions on my > side. > > Inline replies: [snip] > > > Consider a record that is already registered with IANA, TLSA for example. > > > As I understand it, TLSA is not appropriate for publication at a delegation > > point, so using TLSA here would not make any more sense than DELEG. Perhaps > > this should just be some placeholder value, such as MYCUSTOMTYPE? > > > Elsewhere in the document it states the record must be registered, so > > providing an example that is registered seems better than a placeholder > > value for an example. > > I don't have strong opinions on this, but I think DELEG is not a good choice, > because it is a work in progress. OK, I have settled on "NEWRRTYPE" and will use that. > > ### Are 2 modes really needed? > > > > ``` > > 308 It has a single OPTIONAL policy attribute, which takes a boolean > > 309 value with a default value of false. > > ``` > > > > Should this be interpreted as Default Mode is mandatory to support and > > Policy Mode is optional? > > No. The text extract only describes the permitted XML syntax of the extension > elements. > > By default, an <info> command just returns information about the specified > object. The purpose of the <info> Policy Mode is to allow the client to also > determine the server policy, that is, the supported DNS record types and the > corresponding min, default and max TTL values. > > Is it the case that servers always have a policy, but that it is just not > always requested? Yes, servers will always have a policy. Or rather, they will need to decide what the values of the "min" and "max" attributes should be as part of the implementation of this extension (the "default" TTL is whatever value is already used for a given record type). > I'm imagining an implementer who might just prefer to implement one solution, > and get back extra info which they ignore when they don't care. > It feels like there could be a reduction in implementation burden here, am I > wrong about that? Client implementers may well implement a "policy mode by default" approach, that's their choice. A previous version of this document included policy information in all <info> responses, but feedback from the WG was that it should only be included when specifically requested. > > Is Policy Mode supported by `<create>` and `<update>` ? > > > > I assume the answer is yes, but explicit examples might make this clearer. > > No, <info> only. In the document, Default Mode and Policy Mode are only > specified in the context of the <info> command. > > I see... mutations are only setting the ttl value, and the responses never > include the policy information. Correct. > > > ### When can servers ignore the host attribute? > > > > > > ``` > > > 771 EPP servers that use the "host attribute" model SHOULD use any A > > > and/ > > > 772 or AAAA TTL values specified for the domain object when publishing > > > 773 NS, A and AAAA records derived from host attributes. > > > ``` > > > > > > When can this SHOULD be ignored? Why not MUST? > > > This is basically saying the same thing as the preceding paragraph, just in > > the scenario where an EPP server uses host attributes rather than host > > objects. See Section 1.1 of RFC 5731 for an explanation of the difference. > > Thanks, this took a few readings for me to understand, the reason this is not > a MUST is the same. > > You may consider adding a sentence at the end to tie both of these SHOULDs to > section 4, like: > > Regardless of if "host attributes" or "host objects" are in use, Section 4 > explains that TTL values can change out of band. > > This is probably obvious to people with more experience with EPP though. These paragraphs appear immediately before Section 4, so I am not sure adding something is needed. > > ### Operational considerations > > > > ``` > > 796 Historically, registry operators have used a global TTL value for all > > 797 delegations within their zones, which could then be tuned to an > > 798 optimum value. > > ``` > > > > Is this a recommendation? Can it be turned into one or removed? > > It's not a recommendation, just a description of historical practice. It > could be removed. > > This reads to me as a recommendation, if you are not trying to recommend > implementers continue this trend, I suggest removing it. Will do (or rather, have done). > > > ``` > > 800 Registry operators SHOULD implement limits on the maximum and minimum > > 801 accepted TTL values that are narrower than the values permitted in > > 802 the XML schema in the Formal syntax (which were chosen to allow any > > 803 TTL permitted in DNS records), in order to prevent scenarios where an > > 804 excessively high or low TTL causes operational issues on either side > > 805 of the zone cut. > > ``` > > > > This feels like it is in conflict with the Default Mode, which is mandatory > > to support? > > This is not correct. "Default Mode" provides clients with a way to discover > the current TTL settings for an object (as opposed to "Policy Mode" which > also returns the server policy, see above). These two modes, which only apply > to the <info> command, are not intended to, and indeed cannot, effect the > server's ability to implement its own policy in relation to TTL values. > > Does this sentence imply then that there always exists a server policy, even > if it's not requested in the info command? Yes, servers will always have a policy. Or rather, they will need to decide what the values of the "min" and "max" attributes should be as part of the implementation of this extension (the "default" TTL is whatever value is already used for a given record type). > > > ### additional security considerations for ttl > > > > > > Consider commenting on the impact of TTL on DDoS. > > > Consider commenting on the impact of TTL on DNS Spoofing. > > > Consider commenting on the impact of TTL on DNS Cache Poisoning. > > > I don't believe this draft has any implications on these topics. If you > > think it might, then I think I would want to get input from DNSOP and/or > > the DNS Directorate. > > I see your point. The draft simply describes an extension to EPP which > enables clients to manage TTL. > > Since you comment on the impact of choice of TTL value in security > considerations in relation to fast flux, I wondered if you should comment on > the choice of TTL and its impact on these topics. > > Seems fine to leave off these considerations since they are not specific to > this EPP extension, but TTL in general. Noted. G. -- Gavin Brown Principal Engineer, Global Domains & Strategy Internet Corporation for Assigned Names and Numbers (ICANN) https://www.icann.org _______________________________________________ regext mailing list -- regext@ietf.org To unsubscribe send an email to regext-le...@ietf.org
