[c-nsp] DHCP_PD usage for PPPoE Access

[Victor Lyapunov]

Hello

I have been testing some scenarios for IPv6 over broadband
connections. The setup is a the most common one, the CPE gets

-One ::/128 WAN ipv6 address using autonegotiaton.
-A signle ::/56 LAN subnet for the user networks, through DHCP-PD
(further subneted into /64 subnets for the various VLANs in the CPE)

For this setup the NAS server is configured with a local ipv6 pool for
WAN address assignment (autonegotiation)

  ipv6 local pool PPPOE 2001:100::/64 128 shared

And a second pool used by the DHCP_PD

 ipv6 local pool LAN 2001:200::/48 56

In this way I have to maintain two different pools (one for CPEs WAN
and one LAN addressing).
A possible alternative that is discussed, is having the NAS allocate
just the DHCP_PD ::/56 prefix to the CPE (as far as global addresses
are concerned). And then configure the CPE to use the first of the
resulting 256 ::/64 subnets for the WAN and the rest for the LANs.

What is your experience, is the second alternative worth pursuing? Is
there a common practice?

Thanx for the input