IPv6 has fc00::/7 (everything from fc00:: to fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff) as the equivalent to RFC1918 addresses (10.0.0.0/8, 172.16.0.0/12, 192.168

IPv6 has fc00::/7 (everything from fc00:: to fdff:ffff:ffff:ffff:ffff:ffff:ffff:ffff) as the equivalent to RFC1918 addresses (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). You can set some private v6 subnet in DHCPv6 and be happy (or do static assignments or whatever suits you). Also, honestly, using IPv4 on LANs still makes sense no matter what trend the internet goes for.