Re: [v6ops] DHCPv6 PD route injection

[Mikael Abrahamsson <[e-mail]>]

On Tue, 14 Nov 2017, Alexandre Petrescu wrote:

> There is a need to send route updates only if there is a Relay.  When 
> there is a Relay the Server has a GUA.

Commonly, but not necessarily, and also irrelevant to the problem at hand.

> This makes wonder whether in cellular networks the PGW needs to do route 
> injection (route updates) during DHCPv6-PD.

It needs to install the delegated prefix into its RIB/FIB. If it needs to 
tell anyone else about it is a different problem, and it depends on the 
setup. If there is a covering larger prefix statically routed to it then 
it doesn't need to tell anyone else. There is no requirement for the PGW 
to use a routing protocol, but nothing in the architecture that precludes 
it from doing so.

PGW is a router, and in this case for PD it can be either a relay or a 
DHCPv6 server, perhaps with a diameter backend. Depends on how you define 
it, is a DHCPv6-PD delegating router asking Diameter what prefix to 
assign, actually a relay or a server? I don't think it matters anyway, it 
ends up the same thing.

Nontheless, there is no fundamentally different about this, to any other 
situation with a PPPoE terminating BNG for instance.

-- 
Mikael Abrahamsson    email: [e-mail]