Example: I got a virtual machine with its own /64 subnet and the default gateway is reachable via a link-local address. In this subnet there is only one machine, the virtual machine itself.
The machine is reachable when I configure a single IPv6 address and set the netmask to 128. Of course a netmask of 64 also works.
Is there any reason why it's common to still use a netmask of 64?
