nominalism of standards (Re: TCP fallback on timeout)

Paul Vixie paul at
Fri Apr 28 23:50:06 UTC 2017

Paul Vixie wrote:
>> ...
> i'll go further: i think that's a good clarification of and alteration
> to the standards. i just don't think it's wise to expect a tcp-only
> initiator, or a tcp-only responder, to function reliably. (ever.) so the
> standard is nominal, and should guide other standards, but in this case
> may give unusable guidance to implementers and operators.

let me put that differently and perhaps more understandably:

<<That having been said, a stronger document set written today would not
be able to put all of the DNS genies back into their bottles. Too many
implementations have guessed differently when presented with a loose
specification, and interoperability today is a moving, organic target.
When I periodically itch to rewrite the specification from scratch, I
know there are too many things that must be said that also cannot be
said. It’s as though, in a discussion of the meaning of some bit
pattern, a modern description of the protocol—written with full
perspective on all that has been done in the DNS field—would have to
say, “It could mean x but some implementations will think it means y so
you must be cautious.”>>

P Vixie

More information about the Unbound-users mailing list