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

[Suresh Krishnan <[e-mail]>]

Hi Michael/Lorenzo,

> On Nov 2, 2019, at 6:01 PM, Michael Richardson <[e-mail]> wrote:
> 
> 
> Lorenzo Colitti <lorenzo=[e-mail]> wrote:
>>> Please use a documentation prefix, say 192.0.2.0/24, instead of the
>>> RFC1918 address currently used in the example.
> 
>> Are you sure this would be an improvement? The example would become less
>> realistic because 1) 192.0.2.0/24 is a /24 and subnetting a /24 is
>> unusual,
>> and 2) it's seems like a reasonable thing to do to route private space
>> to a different NAT.
> 
> I agree with you.
> 
>> Is there a larger documentation prefix than 192.0.2.0/24?
> 
> I wish that there was.

Me too. I also think a larger prefix could be useful. Similarly a block that would differentiate it as an example of private space to be used.

> Maybe we could carve out of class E space as a /20 of documentation space.

Sounds like a plan. If you write something up, I would be willing to AD sponsor something like this. The biggest issue with repurposing E space was that it would hit a lot of bogon filters. In this case that is a desirable feature.

> 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'd like the IPv6 documentation prefixes to have a pretty high Hamming
> Distance from each other to maximize the visual distinction.

We have a /32 for this. Plenty of ways to be visually distinct including some of the common ones I have used :-)

2001:db8:abba::/48
2001:db8:beef::/48
2001:db8:cafe::/48
2001:db8:dead::/48
2001:db8:face::/48
2001:db8:c001::/48

Cheers
Suresh