For PPPoE, the BNG suggests the IPv6CP protocol to the client during the session setup phase if the appropriate attributes have been returned by the RADIUS server on authentication. The RADIUS attribute that indicates the setup of a PPPoE host is Framed-IPv6-Prefix, which should contain a /64 prefix for the client.
When a PPPoE host has successfully completed the IPv6CP negotiation, the BNG transmits a Router Advertisement to the PPPoE host containing the suggested prefix and any other options that are configured. The client may use this information to pick one or more addresses from the suggested prefix; all addresses within the prefix are forwarded toward the client.
Alternatively, the Recursive DNS Server (RDNSS) option as defined in RFC 6106, IPv6 Router Advertisement Options for DNS Configuration, can be included in the IPv6 Router Advertisements for DNS name resolution of IPv6 SLAAC hosts. See also DNS and NBNS name server IP addresses for subscriber sessions.