Re: Fix IPV6 literal notation?

[Brian E Carpenter <[e-mail]>]

Tim,

On 27-Dec-20 11:16, Tim Bray wrote:
> See https://twitter.com/dave_universetf/status/1342685822286360576 to which I heartily concur. IPV6 addresses are neither easy for humans to read, nor easy for software to parse.
> 
> *If* someone has a better idea, there’s no good reason not to standardize it, the old approach would still work.   Does anyone have a better idea?

I have no idea if there's a proposal in that sequence of Twitter messages, but if there is, it should be written up as an I-D aimed at the 6man WG and discussed there. (Hence I have changed the IETF list to a Bcc: and added the 6man list in Cc:.)

I can say that this much is wrong:

> Oh, and the leading zero debate also infects IPv6, to some extent! The specs tried to specify the textual representation of IPv6, but it failed to be complete. So it's unclear if 000001::00001.00002.00003.00004 is a valid IPv6 address

It's quite clear that it is invalid. RFC4291 section 2.2 says:

  "1. The preferred form is x:x:x:x:x:x:x:x, where the 'x's are one to
      four hexadecimal digits of the eight 16-bit pieces of the address."

As for writing a parser, I'd expect the starting point to be the ABNF in RFC3986 (where the limitation to 4 hex digits is also clear).

Regards
   Brian Carpenter