Re: Additional Documentation Prefixes (was Re: AD Evaluation : draft-ietf-6man-ra-pref64-06)

On Mon, 4 Nov 2019, 06:33 Brian E Carpenter, <brian.e.carpenter@gmail.com>
wrote:

> On 04-Nov-19 06:18, Michael Richardson wrote:
> >
> > Suresh Krishnan <Suresh@kaloom.com> wrote:
> ...
> >     >> I'd also like to have three or four additional IPv6 documentation
> prefixes,
> >     >> plus some documentation space from ULA-R and ULA-C.
> >
> >     > What is ULA-R? Did you mean ULA-L? If so, it would be a pain to
> reserve
> >     > something now since we also need to update RFC4193 to make sure
> that
> >     > the Random “Global ID”s will not collide with the reserved
> prefixes. If
> >     > ULA-C does take off, this would be a good idea to do something like
> >     > this.
> >
> > I guess L=1 is why you call it ULA-L. I have known it as ULA-Random.
> > We are both talking about RFC4193 though.  So such a document would need
> to
> > update RFC4193.
>
> I think this is a bad and pointless idea. Pointless because it is 100% OK
> to use any RFC4193 prefix as an example, since by definition it will never
> be used on the Internet, and the chance of collision on a given ULA site
> is 1 in 2**40 (and who cares anyway?). Bad because it means that millions
> of existing boxes that can generate ULA prefixes would be non-conformant
> and, seriously, is any vendor going to update date their firmware for this?
>

I redacted my ULA in examples in a presentation I did recently. That made
it impossible to type in and for somebody to duplicate.

If the goal is ensure people can't try to use these example addresses on
real networks, then perhaps using invalid addresses in the document with a
note that they're examples and invalid on purpose is a better idea.

For example, using non-hexidecimal letters, with a note about them being
substitutes for 'a' through 'f'.

E.g.

2001:db8:xxxx:yyyy::zzz1

> Regards,
>    Brian
>
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