<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></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 5 Jun 2019, at 11:41, Nick Hilliard <<a href="mailto:nick@foobar.org" class="">nick@foobar.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Because they will have handed back their address space. The address assignment policies are explicitly designed to have a garbage collection mechanism under 2007-01. If you don't actively maintain your registration, it reverts to the registry.</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Nick</span></div></blockquote></div><br class=""><div class="">Sure, but consider this simplified scenario:</div><div class=""><br class=""></div><div class="">1. In June 2019, IXP A requests an allocation. They get a /24.</div><div class="">2. In June 2020, the reserved pool is exhausted.</div><div class="">3. In July 2020, IXP B requests allocation but can't get one due to 2.</div><div class="">4. Sometime in 2021 (or even later), IXP A hands over their allocation.</div><div class=""><br class=""></div><div class="">What would IXP B do in the mean time between July 2020 and 2021 (or even later) when IXP A handed back their allocation?</div><div class=""><br class=""></div><div class="">Of course another IXP could have handed back their address space, but this doesn't change the point made:</div><div class=""><br class=""></div><div class="">Defaulting to a smaller allocation increases the chance (if ever so slightly) that the pool will be exhausted at a </div><div class="">later point and thus IXP B will get an allocation in July 2020.</div><div class=""><br class=""></div><div class="">On a smaller note, I could also tentatively argue that being able to hand over new allocations is more important to ecosystem </div><div class="">diversity than being able to honor requests for increasing existing ones.</div><div class=""><br class=""></div><div class="">Kind regards,</div><div class="">Aris</div></body></html>