You have heard wrong. The first almost half of an ipv6 address is the network/route prefix, then a section for subnet and then the host/interface address. No ipv6 address converts to ipv4. I would guess 6to4 tunnels might assign the interface address as the ipv4 address to simplify things, but that is merely a choice of the tunnel operator. Basically it works through the ipv6 address from left to right to get to the destination. The further right in the address you are the closer you are too the destination interface. The tool you are using to covert addresses is fundamentally flawed. Also fe80 is link local. It's specifically allocated for this function. fe80:: is not owned and cannot be owned by anyone. It is similar to class A,B, and C ipv4 networks, however ipv6 doesn't use NAT, so in practice it is a bit different.
You have heard wrong. The first almost half of an ipv6 address is the network/route prefix, then a section for subnet and then the host/interface address. No ipv6 address converts to ipv4. I would guess 6to4 tunnels might assign the interface address as the ipv4 address to simplify things, but that is merely a choice of the tunnel operator. Basically it works through the ipv6 address from left to right to get to the destination. The further right in the address you are the closer you are too the destination interface. The tool you are using to covert addresses is fundamentally flawed. Also fe80 is link local. It's specifically allocated for this function. fe80:: is not owned and cannot be owned by anyone. It is similar to class A,B, and C ipv4 networks, however ipv6 doesn't use NAT, so in practice it is a bit different.