And yes, if you support version n you also support all versions up to n. -- Mark Andrews
> On 3 Nov 2024, at 09:38, Mark Andrews <ma...@isc.org> wrote: > > BADVERS is sent if the server doesn’t support the version in the request. > As version 1 has not yet been defined every implementation should return > BADVERS to a request with [1..255] in request and the response version > version should be 0. > > We should have bumped the version when we tightened the specification over > the handling of unknown EDNS options but there were too many broken > implementations for that to have actually worked. > > We should make Report Channel be dependent on EDNS(1) but there is still too > many broken implementations out there. > -- > Mark Andrews > >>> On 3 Nov 2024, at 08:57, Casey Deccio <ca...@deccio.net> wrote: >>> >> >>> On Nov 2, 2024, at 8:35 PM, Paul Vixie <paul=40redbarn....@dmarc.ietf.org> >>> wrote: >>> >>> The version number in the initiation is the one that the initiator is >>> expecting in the response. Probably should have made that an array. >>> >>> >>> On Nov 2, 2024 19:54, Dave Lawrence <t...@dd.org> wrote: >>> I agree with your reading. 6.1.3 seems quite clear that request = 0 >>> and response = 0-255 is legit. >> >> (Responding to both messages above...) >> >> So with the following text: >> >> If a responder does not implement the VERSION level of the >> request, then it MUST respond with RCODE=BADVERS. All responses >> MUST be limited in format to the VERSION level of the request, but >> the VERSION of each response SHOULD be the highest implementation >> level of the responder. In this way, a requestor will learn the >> implementation level of a responder as a side effect of every >> response, including error responses and including RCODE=BADVERS. >> >> If requestor sends VERSION 0, responder can send VERSION 0 - 255. Got it. >> >> But when is RCODE=BADVERS expected from the responder? Two scenarios to >> consider: >> >> 1. Requestor sends VERSION n, responder sends VERSION < n >> 2. Requestor sends VERSION n, responder sends VERSION > n >> >> It seems to me that in case 1, RCODE=BADVERS is always expected. >> >> In case 2, it depends on your reading. If a responder implements level n, >> does it implement all versions < n? If so, then RCODE=BADVERS never makes >> sense. Otherwise, the responder's RCODE depends on whether or not they >> implement VERSION n; thus, the RCODE cannot be definitively predicted by the >> requestor. My reading of the spec seems to imply the former, but Paul's >> response seems to imply the latter. >> >> Casey >> _______________________________________________ >> DNSOP mailing list -- dnsop@ietf.org >> To unsubscribe send an email to dnsop-le...@ietf.org
_______________________________________________ DNSOP mailing list -- dnsop@ietf.org To unsubscribe send an email to dnsop-le...@ietf.org
