Redeploying most of 127/8, 0/8, 240/4 and *.0 as unicast

Thu Nov 18 21:39:07 UTC 2021

Nick Hilliard wrote:
> John Gilmore wrote on 18/11/2021 19:37:
>> There will be no future free-for-all that burns through 300 million
>> IPv4 addresses in 4 months.
>
> this is correct not necessarily because of the reasons you state, but 
> because all the RIRs have changed their ipv4 allocation policies to 
> policies which assume complete or near-complete depletion of the 
> available pools, rather than policies which allocate / assign on the 
> basis of stated requirement.  For sure, organisations were previously 
> requesting more than they needed, but if stated-requirement were 
> reinstituted as a policy basis, the address space would disappear in a 
> flash.
>
I think it more likely that organizations will treat new space like they 
do their reclaimed/returned allocations right now. We are not going 
back. IPv4 only becomes plentiful again upon obsolescence.

Need is elastic based upon general availability of supply. To say it 
differently, organizations were requesting more than than they 
absolutely required to get by. And that was ok, because there was no 
reason to require them to twist themselves into engineering pretzels 
when IPv4 was freely available.

Simple example, back in the day you could choose to deploy a T1 customer 
with a public /30 and routed /29 and that would have easily met needs 
requirements.

On the other hand, you could also deploy the same customer with 
unnumbered or private /30 and routed to loopback public /32.

> The point remains that 127/8, 0/8, 240/4 are problematic to 
> debogonise, and are not going to make a dramatic impact to the 
> availability of ipv4 addresses in the longer term. Same with using the 
> lowest ip address in a network block.  Nice idea, but 30 years late.
>
> There's no problem implementing these ideas in code and quietly using 
> the address space in private contexts.
>
> Nick
>
>

Right or wrong, it would be nice to remove any impediment to the effort 
absent justifiable document-able and insurmountable reason why the space 
should NOT be usable.

And those impediments manifest themselves even for quietly using the 
address space in private contexts.

Also, the 30 intervening years have dramatically upped the stakes in 
terms of RoI.

I suggest considering these proposals in the light that IPv4 may be 
obsolete in a decade. And maybe not.

If it is obsolete, whats the harm?

And if it not, the benefits are clearer than ever.

Joe