On 19.7.2017 05:15, Mark Andrews wrote: > In message <[email protected]>, > =?UTF-8?B?UGV0ciDFoHBhxI1law==?= writes: >> On 11.7.2017 13:23, Ted Lemon wrote: >>> On Jul 11, 2017, at 3:17 AM, Petr paek <[email protected] >>> <mailto:[email protected]>> wrote: >>>> I feel that implications from switch to non-RR format are >> underestimated >>>> and following e-mail attempts to explain why I believe it is a bad >> idea. >>>> Please accept my apology for such long e-mail. >>> >>> Petr, with all due respect, I did not see a counter-proposal here, and >>> your comments seem to reflect a misunderstanding of what >>> session-signaling is. >>> >>> In fact, the opposite of what you said is true: if this were done as a >>> normal query with EDNS0-like encapsulation, _then_ we would see >>> problems, because session signaling messages would look more like DNS >>> queries, and less like control messages. This is not a desirable >> quality. >>> >>> It's true that, for example, the DNS packet compression format would >>> have to deal with this specially, but that would also be true if this >>> were done EDNS0-style. It's true that packet dumpers would have to >>> deal with this specially, but that's also true if it's done EDNS0-style. >>> Etc. >> >> Let me clarify that I'm not insisting specifically on EDNS0. From my >> perspective anything which does not deviate from current wire format is >> okay. >> >> >>> It may be that there is a good point in your argument somewhere, but at >>> the moment, I don't see one. E.g., in your python example, yes, if >>> this were an RR, not being able to plop it into your RR-handling switch >>> would suck. But it's not an RR, doesn't have the semantics of an RR, >>> and if you plop it into your RR-handling switch, you're probably getting >>> the semantics wrong. >> >> This might be key to the the misunderstanding: >> >> I'm not talking about semantics at all. What I object to is the proposed >> wire format, not the semantics. The fact that bytes are stored in format >> compatible with RR (RFC 1035 section 4.1.3) is not related to its >> semantics. >> >>> So if you want to make this case, I think you need to be more specific >>> about why this is a problem: when I think about how to implement this >>> (which I have done, because I'm using it for dnssd), what you are >>> advocating seems harder, not easier, than what is currently being >> proposed. >> I'm trying to explain that deviance from RR format (RFC 1035 section >> 4.1.3) will force parties in the DNS ecosystem to implement support for >> the new wire format even though they are not interested in session >> signaling at all. > > Hogwash. Servers which are unaware of the opcode will return NOTIMP > or FORMERR depending on how forward thinking the developer was. > > If you have a packet dumper YOU ALREADY HAVE TO ACCOUNT FOR THIS. > There are ZERO guarentees that a packet addresses to/from port 53 > is a DNS packet. If your packet dumper can't handle these then > it is already broken. > > If you are just proxying DNS messages this should be transparent. If > the proxy is parsing the message then it returns NOTIMP or FORMERR. > >> For a lot of cases it would be sufficient if SS data could be treated as >> one of many "unknown RR types" (RFC 3597). For example tools for >> statistics would work, the capture formats would not need special >> extensions for SS, etc. >> >> We can discuss this in depth during dnsop session today. WG decided to go forward with TLV format. I still think it is a mistake but I'm going to respect WG decicion and thus I'm giving up. Further discussion on this topic is pointless.
-- Petr Špaček @ CZ.NIC _______________________________________________ DNSOP mailing list [email protected] https://www.ietf.org/mailman/listinfo/dnsop
