The document describes how to configure a dual IPv4/IPv6 network using Neighbor Discovery Router Advertisement (NDRA) and DHCPv6 prefix delegation over PPPoE. It provides background on why service providers implement dual stacks and the types of IPv6 addressing needed - WAN link addressing for the CPE WAN interface and subscriber LAN addressing. NDRA is used to autoconfigure the CPE's global IPv6 address on the WAN link, while DHCPv6 prefix delegation provides IPv6 addresses for devices on the subscriber LAN. The document includes a step-by-step configuration example.