Everyone suggesting that ::ffff:0:0/96 is a solution should note that not all network stacks are "unified". Windows' stack isn't unified (try accessing http://[::ffff:7f00:1]/ while having a loopback server and it won't work) and most non-Linux embedded OSes separate the network stack for size reasons (to the chagrin of IPv6 promoters, but most of them are simply trying to fit something into the half-MB EEPROMS like how most IoT devices don't have 5GHz Wifi support).