On Wed, 10 Jun 2015, Baldur Norddahl wrote:
We use DHCPv6 to assign just one IP address to the CPE. This is because otherwise our routers do not know where to route the /48 that is also passed along with DHCPv6-PD.
If you use DHCPv6-PD you only need a LL address, you do not need a GUA address. Yes, a GUA WAN address is nice for fault finding, shows up in traceroute etc, but it's not needed. If your routers require a GUA WAN address in order for DHCPv6-PD to work, then they're not standards compliant.
Apart from operational simplicity, we also do not want our routers to keep track of a million ND cache entries. Our system pushes that down to the CPE. In the network we only have one ND cache entry per customer.
Well, if you have a GUA /128, then you have two per customer (because you'll have the LL one as well). If you didn't use the GUA address, you'd only have one. -- Mikael Abrahamsson email: swmike@swm.pp.se