NAT64 IPv6 Prefix to IPv4 Address Persistent Translation (464XLAT)

This feature, which is targeted at IPv6 mobile networks, is used with the dual-translation mechanism, 464XLAT, to enable IPv4 services to work over IPv6-only networks. It augments the existing NAT64 mechanism, which enables IPv6 clients to contact IPv4 servers by translating IPv6 addresses to IPv4 addresses (and vice versa). However, the existing NAT64 mechanism does not ensure a sticky mapping relationship for one unique end user. By configuring the new address-persistent option with a specific IPv6 prefix length for NAT64 translations in an IPv4 source NAT pool, a sticky mapping relationship is ensured between one specific IPv6 prefix and one translated IPv4 address.