DHCPv6 relay with PD

[Nick Hilliard]

Ole Troan wrote:
> It shouldn't be the IETF's job to tell people how to run their networks.
> The IETF provides the building blocks.

Take a DHCP server, an ISP access router and a CPE.

The CPE connects to the ISP access router and issues a dhcp request.
This is relayed by the access device to the dhcp server which replies to
access device with a PD reply.  The access router relays this reply to
the CPE.

At this point, the state is that both the CPE and the dhcp server know
the delegated prefix, but the access router does not.  The result is
that the customer's prefix is not routed to the CPE.

The question is: how do we make this work so that PD is a viable
mechanism for handling customer ipv6 requirements?

The ISP operator cannot listen to the CPE if it's running a routing
protocol because the access router has no way of determining whether any
announcement it receives from the CPE is a legitimate announcement,
because it has no knowledge of what is or isn't assigned to a particular
customer.

Installing static routes on the access router is non-scalable and
constrains the network architecture in a way which isn't feasible.

It might work if the access router implements dhcpv6 snooping, but the
isp operator has little or no control over this.

I know you're not trying to be unhelpful here, but brushing this off as
someone-else's-problem is not going to make the problem go away.  Nor is
claiming that this is a problem with how the network is run, because
this isn't a problem that operators can feasibly fix because it's a
problem that vendors need to solve, potentially helped with some
guidelines from the ietf.

Nick