I like to put some servers behind that scheme. 2601::443:xxxx for https servers 2601::25:xxxx for MTA servers. 2601::993:xxxx for IMAP It gives a quick note of what is that ip even though it’s ipv6 and usually non-human readable. Not sure what kind of scheme is use by medium/big ISP. Do you go by zip code of the area covered or some kind of logical to help people know what is behind that ipv6 network? Jean From: NANOG <nanog-bounces+jean=ddostest.me@nanog.org> On Behalf Of Baldur Norddahl Sent: November 28, 2021 8:22 AM To: NANOG <nanog@nanog.org> Subject: Re: IPv6 and CDN's søn. 28. nov. 2021 13.59 skrev Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp <mailto:mohta@necom830.hpcl.titech.ac.jp> >: But, with manually configured IP addresses, it is trivially easy to have a rule to assign lower part of IP addresses within a subnet for hosts and upper part for routers, which is enough to troubleshoot most network failures. 99% if not 100% of our subnets have either only routers or only hosts + a gateway. So that would be a strange rule to follow. Also very expensive if we are talking public addressing. I find that 10.x.y.z is not much if you want to have a system in your subnet numbering. With ipv6 there is much more space to enable systematic numbering schemes.