... just add an extra octet
For the N'th time, that simply doesn't work.
IPv4 has no provision for any form whatever of address extension. Adding an extra byte, or an extra bit for that matter, will fail on every single IPv4-only computer, router, etc. There is, mathematically, logically, no way round a new version that is necessarily incompatible on the wire. That's why the *only physically possible solution* is a new packet format. That has a lot of implications, most of which are independent of the design details.
IPv6 just works, these days, as far as domestic, cell phone, or small offices are concerned. Yes, there's work to do for larger enterprise networks, hosting providers, and ISPs. No way out of that, but it's part of the price of doing business these days, or should be.
Biting the hand that feeds IT
