Making Use of 240/4 NetBlock

Greg Skinner gregskinner0 at
Sat Mar 12 05:30:48 UTC 2022

> On Mar 10, 2022, at 8:44 PM, Masataka Ohta <mohta at> wrote:
> IIRC, at some time, perhaps when CIDR was deployed widely and
> having something other than IPv4 was a hot topic, there was a
> discussion on releasing 240/4 in IETF. Reasonings against it were
> that the released space will be consumed quickly (at that time,
> NAT already existed but was uncommon) and that new IP will be
> designed and deployed quickly (we were optimistic).
> 						Masataka Ohta

There have been many discussions about 240/4 in the IETF.  For some examples, query “240/4” in the ‘ietf’ mail archive <> on

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the NANOG mailing list