spf-discuss
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Re: [spf-discuss] Feature list for SPFv3

2009-07-17 06:40:23
Scott Kitterman wrote:
Personally I'm more interested in getting SPF v 1 standardized and out of experimental status. I suspect we can work on both in parallel as long as we are clear to keep them cleanly separated.

The key distinction as I see it is SPF v 1 updates MUST be backwards compatible, while SPF v 3 has more freedom to innovate.

IMHO, v3 MUST be backward compatible.

I don't see the point of changing v1: it is rfc4408. A new version has to be marked as such. If we introduce any new feature, or slightly change the meaning of an existing feature, anyone willing to change existing record can change the version number as well. OTOH, anyone who interprets existing v1 records, is better off sticking to v1 specification.

I don't think there is much freedom to innovate with v3. SPF checks will be carried out by old and new software alike, and I don't think it is a Good Thing that the results vary widely. SPFv3 can just work on the SPF RR type, recommending that a corresponding TXT record tagged spfv1 be still maintained. Old rfc4408-software should discard new SPF RRs starting with "v=spfv3" according to step 1 of section 4.5, and then proceed with "v=spfv1" RRs, probably but not necessarily of type TXT, if any. New software should try TXT if it finds no SPF RR, and accept "v=spfv1" for backward compatibility, but there is no need to consider RRs of type SPF that start with "v=spfv3" (I think that's what Stuart meant by "exclusively".)

IMHO, we should publish a single new RFC that prescribes a behavior that is backward "compatible", for some acceptations of "compatible", with both spfv1 and SenderID. We'll have to check with someone at the IESG how many changes would be allowed for aiming at standard track, but we have first of all to consolidate the existing use cases, which may limit the amount of changes that would make sense to introduce.

I've had a try at publishing that wiki page, using the text above, see http://www.openspf.org/Community/SPFv3

I haven't been able to create an SPFv3 subfolder. Navigating back from a feature page to the SPFv3 URL just above is a bit of a nuisance.


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