Yeah but they could've picked something that at least lets the 4 byte host talk to a 5 byte one. Like if I have 8.8.8.8 and they want to give me 8.8.8.8.0, cool. Or make it 8 bytes instead of 5, same thing.
well, if you want to add an extra byte you kinda have a problem, since v4 is fixed format and is actually cooked into hardware in a lot of places. so if you want to keep v4 mostly untouched you have to use an option, which is going to be pretty slow on the backbone.
you can send a packet from an extended address host to a vanilla v4 host if you map the address space into a range like you suggest..but that v4 host just has no way of sending a message back..so its kinda useless
It'd be useless until everyone switches to the 5-byte thing and people can start putting something besides 0 into that last byte. But at least they could turn on v5 or whatever it's called without having to think about it. Right now I could have two hosts that both agree to use ipv6 and it's still hard because you have to reconfigure everything.
v6 already gives you what you're asking for here: you can turn it on without thinking about it, but actually using the extra addresses from it requires reconfiguring some things (not everything, mind).
Why is that bad when it's v6 doing it, but good when it's your 5-byte thing doing it? Or did you just not think through this enough to realize you were asking for something we already have?
Because you can't generally turn on v6 without thinking about it. Maybe consumers can, even then not always cause it messes random things up. Power users and offices maybe can't. Service operators really can't. If it were as easy as you're saying, all those things like Github would already at least support v6.
Windows, Linux, OSX, Android and iOS all ship with v6 enabled by default out of the box, so it's already turned on without you needing to think about it. You have to deliberately go out of your way for this not to be the case.
> If it were as easy as you're saying, all those things like Github would already at least support v6.
This isn't the "turn it on" stage, it's the "people can start putting something besides 0 into that last byte" stage.
you can send a packet from an extended address host to a vanilla v4 host if you map the address space into a range like you suggest..but that v4 host just has no way of sending a message back..so its kinda useless