It is possible to include the IPv4 address into IPv6 address. For example,
2001:db8::c0a8:6301 where last 32 bits are IPv4 address
192.168.99.1. There is even a special notation of IPv6 address where last 32 bits are in dot-decimal notation. Example from Juniper router:
root@mx> show configuration interfaces ge-0/0/0 unit 0 family inet6 address 2001:db8::192.168.99.1/64; root@mx>
Under which circumstances it makes sense to include the IPv4 address into IPv6 address? Has anyone seen this in practice?