On Fri, Jun 19, 2026 at 12:50 PM Gary Sparkes via NANOG < [email protected]> wrote:
> > So in IPv6 I either have to renumber because I ditched some ISP for > another...or I have to pay for my addressing space and my ISPs have to > support routing my address space, right? > > Yes, exactly like you had to for IPv4. No, I didn't. In IPv4 I can use RFC 1918 internally in a structured way and NOT have to renumber if I switch ISPs. I unfortunately have to use NAT, and my single public IP will change, and I probably have to update a few DNS records . But the big huge promise of IPv6 was "everyone and their dog can have a block of addresses bigger than the current internet" and "there's no more NAT or private addresses". NAT 1:1 doesn't help here. Instead of having a single public IPv4 with port forwards for MX (25, 465, 993, 110, etc...) and maybe a few for SSHing to various boxes (22, 221, 222, 223, etc...) I now have a block bigger than the internet on my WAN that has to be 1:1 mapped into my MX (which used to be .250) and the various SSH hosts (.1, .2, .3, etc...)...and I need to update external DNS for MX to point to isp:bloc:k::1 for mail and isp:bloc:k::7 for one SSH host, etc... Seems like it would be *way* simpler to say "here's youre free PI /48 your business can use, go number your internal network how you want and to connect to the internet, you need to give your ISP(s) your /48 so they can route it". ...at least on the business side of adopting IPv6. On the "back end" everyone's routing tables would probably explode. -A _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/3QLSHPS26UJEPWWDNRHTC3SQ6N4EITU3/
