That’s pretty cool. I crammed to pass the CCNA, and some of its fading from my head now. I could use a refresher. Thanks!

Ah. Well that’s nonsense, but it is a take on the graphic with some internal cohesion.

Two reasons.

You were responding to someone who offered a /24 as a subnet.
There are 32 bits in an IPv4 address. /24 is 255.255.255.0.
So they were wrong too in reference to IPv6, but at least they were making sense.
You responded with /128, which is the full range of the IPv6 address.
That would be like the prior poster saying /32 aka 255.255.255.255.
There’s no usable range there.

And, see my post above for the rest of the breakdown, but you were looking for /64.

0111111.00000000.00000000.00000001
But I doubt your momma can read that.
Mine can’t. She’s not interested in binary or hex, despite my efforts to convince her how fascinating the topic is.

Well, sort of.
You can divide up IPv6 addresses as you like.
But … there’s so much space there that they are typically just divided in half.
64 bits of subnet (aka routing prefix) + 64 bits of host address.
They play a lot of games with the first 12 or so bits to say what kind of network it is, and the rules change a lot for multicast and other address types.
So its not a subnet as you know it, but it still is.

no.

um … that’s wrong.