For cellular networks with IPv6 support, the support of DHCPv6 prefix delegation is only expected to be provided with 3GPP Release 10. So for cellular networks earlier than Release 10, the only way to assign just one /64 prefix to a terminal device is, for example, by using router advertisements. In the case of smartphones or laptops, this method allows IPv6 support to be implemented relatively simply. However, each IPv6 router needs at least one additional prefix that it can propagate to clients on the LAN.
IPv6 prefix delegation from the WWAN into the LAN makes it possible for clients to use the /64 prefix, as assigned on the WAN cellular network side, to be used on the LAN. This makes it possible to operate a router in an IPv6 cellular network without DHCPv6 prefix delegation and neighbor discovery proxy (ND proxy). The router announces the assigned /64 prefix by router advertisement on the LAN, rather than adding it at the WAN interface. Clients can then generate an address from this prefix and use it for IPv6 communication.
To do this, you configure the IPv6 Internet access in the normal way. Additionally you should go to and, for the corresponding WAN interface, switch the parameter PD source type from "DHCPv6" to "Router advertisement".
The following restrictions apply:
- You can only use the feature on point-to-point connections (such as PPP), whereby the remote station automatically sends all traffic to the router because there is no ND proxy.
- You can create only one IPv6 network in the LAN, because only one /64 prefix is available.
- This feature is not suitable for scenarios where an interim router cannot or does not perform prefix delegation, with the exception of point-to-point connections.
- The automatically generated IPv6 address on the WAN interface cannot be reached from clients on the LAN, because there is no ND proxy.