Like fd::1? Valid ipv6 that is shorter than an ipv4 address

Nah, "1.1" is a valid IPv4 address (Cloudflare DNS) and it's shorter

Touché, I guess I should’ve said a typical v4 address. Short hand v4 addresses aren’t as common knowledge though

fd::1 is a reserved address. Did you mean fd00::1?

fd::1 == 00fd::1. The :: expands to fill the available bits with 0

fd::1 == 00fd::0001, which is reserved by IETF.

The :: only expands to fill all-zero hextets.

Good catch, that is correct. Thank you

This thread shows that the ipv6 notation is more complicated. It's good to at least use a smaller address space on a LAN like this, but I want the basic decimal notation.

Decimal is actually a nightmare for dealing with common CIDR prefixes. Would you rather write '1111111111110000' as fff0 or 65520?

Yes, which is why they shouldn't use those huge prefixes. There's an existing 32-bit address space represented nicely like 8.8.8.8 or 192.168.1.2 for local. Now that we want to extend the address space for more users, the newer ones can be like 8.8.8.8.6 without messing with the existing ones.

Oh and I'd actually prefer the 65520.

You'd still need to upgrade and change every device. There have been transitional software that used ipv6 but allowed for ipv4 address notation. [1] Example: ::ffff:0:8.8.8.8

The huge prefixes allow for a simple hierarchical network structure and gives us room to redo the address scheme if we end up wanting to (only a portion of addresses space is currently allocated right now) without having to go through this entire upgrade the internet again.

[1] https://en.wikipedia.org/wiki/IPv6_transition_mechanism

Right, I've seen the padded v4-like v6 address spec, but that's not how they attempted to transition everything. ISPs gave everyone new v6 addresses, and the whole home/office router/NAT/PC ecosystem put v6 on a totally separate plane with ::: style addresses presented to users. I understand that the clean slate of reallocated addresses would solve some problems, but they could have focused on just getting all that hardware and software onto the ipv6 protocol with minimal changes before attempting to basically redo the entire Internet along with every LAN.

As an end user who has a choice, they have to give me something that's not harder to use than before. I think they could have managed that if it were a priority.

Not sure I understand. Right now you should have dual stack, which should be easier than merging the v4 onto the v6 network. You didn't have to change anything to keep working with v4 and if you want to work with v6 then that's an option for you but you can disable if you really want.

I'd like to use v6 in the dual-stack setup, just with all the v4 addresses copied over so the only change is that I'm using a different protocol under the hood.