Re: IETF proposal to unicast 127.1/16 - should we be concerned?

On 18/11/2021 09:51, Jonathan McKeown wrote:
> On Thu, 18 Nov 2021, 07:50 Dewayne Geraghty, <
> dewayne@heuristicsystems.com.au> wrote:
> 
>> As this is an individual proposal within the IETF framework, the concern
>> should be tempered, however the draft proposal for 127.1/16 to be
>> routable is being discussed.
>>
> 
> As I read it, the proposal is more wide-ranging than that, allowing all of
> 127/8 to be routable with the exception of 127.0/16 which is still reserved
> for loopback.

I think the killer for this proposal will be this line from section 3

"All host and router software SHOULD treat 127.1.0.0 to 127.255.255.255
as a global unicast address range."

Given that affects every operating system out there, and every existing
piece of kit, many (most?) of which don't get updates, getting the world
into compliance will probably take at least as long as IPv6 adoption did(*).

It also increases the address space by a mere 0.4%, which is a drop in
the ocean. In an ideal world IETF would declare global EoL for IPv4 in
say 2040, and push the backbone infrastructure onto IPv6, while
accepting private IPv4 enclaves will exist indefinitely.

(*) Yes, my tongue is firmly in my cheek.

-- 
Nothing teaches one not to try to stamp out burning thermite quite
like real-life experience.
			— James Davis Nicoll