ietf-mxcomp
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Re: TECH-OMISSION (-protocol): Partial IPs with CIDRs allowed?

2004-09-08 03:25:33


On Sep 8, 2004, at 12:09 AM, wayne wrote:


In <20040908020217(_dot_)GB23667(_at_)dumbo(_dot_)pobox(_dot_)com> Meng Weng Wong <mengwong(_at_)dumbo(_dot_)pobox(_dot_)com> writes:

I have the feeling that people are going to write the first
form, so we might as well require implementations to support
it.  As long as it's not ambiguous, lazy is okay.

Similarly "ipv4" and "ipv6" being synonyms for "ip4" and
"ip6", and "a:1.2.3.4" being interpreted as "ip4:1.2.3.4".
That seems to happen rather often.


<rant>

[snip]
I strongly believe that implementations MUST detect all syntax errors
and return PermError in such cases.

If we want to support these common deviations from the spec, I think
we should put them into the spec and have all implementations support
them.

I can not agree more. A spec that has a large number of common deviations is not a spec. It's a series of suggestions, and you wind up with a myriad of implementations doing all kinds of things, and it becomes impossible for a publisher to know if the record is really right or not. A spec with many deviations tends to encourage more deviations and "improvements". Consistency is a BIG part of keeping it simple.

I don't mind if the syntax is extended to include the variants listed above, but it needs to be in the spec.

This reasoning applies to the MUST and SHOULD debate about TXT and the new SPF RR as well. If it's allowed, say so. If it's not, it's an error. And don't spec things that many implementations can't comply with!

This is email we are talking about, not some formatting of a web
page.  I think it would be very bad to require ever implementation of
SPF/SenderID to know about weird voodoo magic that is needed to work
reliably the way web browers are required to know.

Well, it's pretty bad on a web page too. The browser mess wastes buckets of development time in every organization all over the world. Let's not do that.

Margaret.