[DNSOP] Mirja Kühlewind's No Objection on draft-ietf-dnsop-session-signal-19: (with COMMENT)
Mirja Kühlewind <firstname.lastname@example.org> Thu, 06 December 2018 22:09 UTC
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Mirja Kühlewind has entered the following ballot position for draft-ietf-dnsop-session-signal-19: No Objection When responding, please keep the subject line intact and reply to all email addresses included in the To and CC lines. (Feel free to cut this introductory paragraph, however.) Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html for more information about IESG DISCUSS and COMMENT positions. The document, along with other ballot positions, can be found here: https://datatracker.ietf.org/doc/draft-ietf-dnsop-session-signal/ ---------------------------------------------------------------------- COMMENT: ---------------------------------------------------------------------- Thanks for address my discuss! ------------------------ These are old comments for the record: 1) sec 3: I really find it a bit strange that there is normative language about error handling (as well as in the "same service instance" definition part) in the terminology section. Maybe move those paragraphs somewhere else...? Also the part about "long-lived operations" and messages types provides far more information than just terminology and I would recommend to also move it into an own section or maybe just have it as part of the intro. 2) Maybe call section 5 "Protocol specification" instead of "Protocol details"...? 3) Sec 5.1: "DSO messages MUST be carried in only protocols and in environments where a session may be established according to the definition given above in the Terminology section (Section 3)." I don't get this. Which part of section 3? Given section 3 is on terminology and this is a normative statement, I would recommend to spell out here explicitly what is meant. Do you mean the protocol must be connection-oriented, reliable, and providing in-order delivery? Any thing else? However, given that you say two paragraphs onwards that this spec is only applicable for the use with TCP and TLS/TCP, do you even need to specify these requirements normatively? 4) sec 5.1 "It is a common convention that protocols specified to run over TLS are given IANA service type names ending in "-tls"." Not sure this is true. Isn't it usually just an "s" at the end? Or with registry are you talking about? 5) sec 5.1: "In some environments it may be known in advance by external means that both client and server support DSO, ..." I guess the client and server also need to know if TLS is supported or not. Maybe spell this out as well. 6) sec 5.1: "... therefore either client or server may be the initiator of a message." Maybe s/initiator of a message/initiator of a message exchange/ 7) sec 5.1.2: "Having initiated a connection to a server, possibly using zero round- trip TCP Fast Open and/or zero round-trip TLS 1.3, a client MAY send multiple response-requiring DSO request messages to the server in succession without having to wait for a response to the first request message to confirm successful establishment of a DSO session." Why is the ability to send more than one request related to TCP Fast Open/TLS1.3 0-RTT? These are two independent mechanisms to speed up processing. Mentioning TCP Fast Open/TLS1.3 0-RTT here is rather confusing. Respectively I also don't think that the sentence: "Similarly, DSO supports zero round-trip operation." is describing quite the same. 8) Further please provide references to TCP Fast Open and TLS1.3 and maybe rephrase this paragraph to use normative language: "Caution must be taken to ensure that DSO messages sent before the first round-trip is completed are idempotent, or are otherwise immune to any problems that could be result from the inadvertent replay that can occur with zero round-trip operation." Maybe just: "DSO messages sent with TLS1.3 0-RTT before the TLS handshake is completed or in TCP SYN data with use of TCP Fast Open MUST be idempotent." However, this is actually already required by TLS1.3 and TFO, so there is after all no need to just rephrase this requirement here (at least not normatively). I think it would be more useful for every DSO message type to specify if it can be sent in 0-RTT or not and require this for specification of future TLVs. 9) sec 5.1.3: "In cases where a DSO session is terminated on one side of a middlebox, and then some session is opened on the other side of the middlebox in order to satisfy requests sent over the first DSO session, any such session MUST be treated as a separate session." This sentence seems a bit non-sensical, which probably isn't great for a normative sentence. If a session is terminated and open of the other end, doesn't that mean that you have two sessions? 10) sec 5.1.3: "A middlebox that is not doing a strict pass-through will have no way to know on which connection to forward a DSO message, and therefore will not be able to behave incorrectly." I'm not sure I understand this sentence. Can you clarify? 11) As already briefly mentioned by Ben, there is quite some redundant text in sec 5 (with 5.2) for handling of message IDs and TLVs. Given this text is normative, I would really recommend to only specify it clearly once. Please also check the rest of the doc further things that are specified normatively multiple times. It usually makes it must clearer to specify it only once, at least normatively, at the appropriate position in the doc. 12) sec 5.3.1: "When a DSO unacknowledged message is unsuccessful for some reason, .." What does unsuccessful mean here? Can you clarify? 13) sec 6.5.2: "A corporate DNS server that knows it is serving only clients on the internal network, with no intervening NAT gateways or firewalls, can impose a higher keepalive interval, because frequent keepalive traffic is not required." I guess in this scenario it is probably most appropriate to not send any keep-alives… 14) sec 6.6: " o The server application software terminates unexpectedly (perhaps due to a bug that makes it crash)." This bullet point does not really make sense to me because at that time when the app is crashed there is no way for the server anymore to perform any actions. 15) sec 7.1: "When a client is sending its second and subsequent Keepalive DSO requests to the server, the client SHOULD continue to request its preferred values each time. " I don't understand the SHOULD here.. what else should be client put in these field instead...? 16) sec 7.1.2: "Once a DSO Session has been established, if either client or server receives a DNS message over the DSO Session that contains an EDNS(0) TCP Keepalive option, this is a fatal error and the receiver of the EDNS(0) TCP Keepalive option MUST forcibly abort the connection immediately." This is normatively specified multiple time (3?) in the doc. Please consider to only specify it once where most appropriate (probably section 7.1.2) 16) sec 7.1: "The Keepalive TLV is not used as an Additional TLV." This is redundant with the normative sentence in the next paragraph. Maybe just remove this sentence...? 17) +1 to Ben's discuss regarding the reconnection of clients. A TCP RST can be sent for many reasons and waiting for an hour seems not appropriate. I would rather recommend to log an error and directly try to reconnect.
- [DNSOP] Mirja Kühlewind's No Objection on draft... Mirja Kühlewind