<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Mar 10, 2022, at 8:44 PM, Masataka Ohta <<a href="mailto:mohta@necom830.hpcl.titech.ac.jp" class="">mohta@necom830.hpcl.titech.ac.jp</a>> wrote:</div><div class=""><div class=""><br class="">IIRC, at some time, perhaps when CIDR was deployed widely and<br class="">having something other than IPv4 was a hot topic, there was a<br class="">discussion on releasing 240/4 in IETF. Reasonings against it were<br class="">that the released space will be consumed quickly (at that time,<br class="">NAT already existed but was uncommon) and that new IP will be<br class="">designed and deployed quickly (we were optimistic).<br class=""><br class=""><span class="Apple-tab-span" style="white-space:pre">     </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span><span class="Apple-tab-span" style="white-space:pre">    </span>Masataka Ohta<br class=""><br class=""></div></div></blockquote></div><br class=""><div class="">There have been many discussions about 240/4 in the IETF.  For some examples, <a href="https://mailarchive.ietf.org/arch/browse/ietf/?q=%22240/4%22" class="">query “240/4” in the ‘ietf’ mail archive</a> on <a href="http://mailarchive.ietf.org" class="">mailarchive.ietf.org</a>.</div><div class=""><br class=""></div><div class="">—gregbo</div></body></html>