[tialaramex]

IPv4 numbering sucks. IPv6 lets you stop worrying about that.

In IPv4 you're going to need RFC1918 addresses, and then you're going to have to make sure that _your_ RFC1918 addresses don't conflict with any _other_ RFC1918 addresses that inevitably absolutely everything else is using or else you'll get hard-to-debug confusion. No need in IPv6, you should use globally unique addresses everywhere, there are plenty and you will not run out.

Everybody who has ever used a single byte to store a value they were convinced wouldn't need to be more than a few dozen, and then it blew up because somebody figured 300 ought to fit and it doesn't already knows in their heart that they shouldn't be using IPv4 in 2019.

[geofft]

Oh, yes, IPv6 saves you from worrying about addressing, which is a huge headache in IPv4. I agree with that and IPv4 address conflicts are a personal frustration. IPv6 doesn't save you from "fancy routing" and mostly does not save you from "nat," though. That's what I was responding to.

I'm hesitant to use IPv6 because it is not merely IPv4 + more addresses, it's IPv4 + more addresses + a very clever design that hides the L2 vs. L3 distinction by relying heavily on multicast groups + a replacement for ARP + a replacement for DHCP + etc. etc. etc. I know I shouldn't be using IPv4 in 2019, but I don't have a better option. I'm not excited about clever systems, hiding, the assumption that multicast works reliably, losing the last few decades of monitoring and debugging tools, happy eyeballs, etc., and I'm not willing to subject my users to the resulting outages simply because it'll save me the headache of thinking about numbering.