Re: Fix IPV6 literal notation?

[Gyan Mishra <[e-mail]>]

I agree just on difficult to read and hard to parse.

For operators NOC and support the biggest complaint has been trying to
decipher the prefix,  subnet and host portion.  Over the last 20+ years I
have provided NOC and support training on IPv6 addressing and subnetting
basics.  Definitely a learning curve for any network support organization.

Main complaints from network engineers and grasping of basic concepts:

Understanding the hex format as it’s completely different from IPv4 decimal.

Understanding the bit pattern as it repeats in subnetting.

Understanding that Hex goes A-F in each 4 hex character field within each
16 bit field and that provides the combinations of addresses per bit
boundary.

The  :: Os compression helps, however does add confusion and needs
explanation and I usually tell folks to write out all the 0s then convert
to compressed format to help understanding of the compressed format.

Understanding that when an IPv6 prefix is written that the leading higher
order hex 0s are the not displayed within the hex field which leads to
confusion.

Happy Holidays!!

Gyan


On Sat, Dec 26, 2020 at 6:25 PM Brian E Carpenter <
[e-mail]> wrote:

> 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
>
>
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*Gyan Mishra*

*Network Solutions A**rchitect *



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