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

On Mon, 4 Nov 2019 at 11:21, Michael Richardson <mcr@sandelman.ca> wrote:
>
>
> Brian E Carpenter <brian.e.carpenter@gmail.com> wrote:
>     >> 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?
>
> So, each time a document uses a ULA-Random in an example that calls for ULAs,
> someone will ask why they didn't use 2001:db8::/32.
>
> The other plus is places that ask for a ULA to be typed in can recognize the
> Documentation prefix, and suggest that maybe that's not what they wanted to do.
>
> {I don't expect any ULA generator to get updated, as you said, 1/2**40.
> But, on the other hand, how many ULA generators are out there?}
>

How ever many CPE there are that follow RFC 7084, "Basic Requirements
for IPv6 Customer Edge Routers" or its ancestor RFC 6204.

That includes all CPE running OpenWRT, the commercial CPE at my
sister's house which she received from her residential ISP without my
involvement (advertising a correctly generated ULA /48 on its LAN
interface, even though IPv6 isn't enabled on the WAN), and one or two
IPv6 CPE I looked at in 2010.

> --
> ]               Never tell me the odds!                 | ipv6 mesh networks [
> ]   Michael Richardson, Sandelman Software Works        |    IoT architect   [
> ]     mcr@sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [
>
>
>
>
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