Re: [v6ops] How do you solve 3GPP issue if neither operator nor handset supports PD?

[Mark Smith <[e-mail]>]

On Thu, 26 Nov 2020 at 09:27, Michael Richardson <[e-mail]> wrote:
>
>
> Mark Smith <[e-mail]> wrote:
>     > This would have been making a specific layer 2 involved in layer 3,
>     > coupling layer 3 advancement to that layer 2.
>
> So why does it matter at all?
> The point is to make things work better for the set of layer-2 that use PPP.
> That set is rather large.
>
>     > IPv6 has moved away from layer 2 extensions or protocols to operate or
>     > configure layer 3, and the advantage is that options can be added to a
>     > protocol that operates at the IPv6 layer, and it automatically works over
>     > all current and future link layers.
>
> That's an interesting statement, which I don't think is at all relevent.
> On what authority to make this statement?
>

Christian Huitema's IPv6 book. You can also see that theme in the ND RFC:

"Placing address resolution at the ICMP layer makes the protocol
      more media-independent than ARP and makes it possible to use
      generic IP-layer authentication and security mechanisms as
      appropriate."

The NBMA RFC (RFC2491) also is generalising multicast emulation over
NBMA networks so that standard IPv6 unicast and multicast protocols
like ND can be used over NBMA.


> The document explains that this is about announcing capabilities so that the
> Layer-3 configuration mechanism can be tuned better.
>
> We could do this in layer-3, but we usually need to decide, (in a BMS),
> BEFORE starting the RA daemon, if we should be allocating a /64 to the link or not.
>

That sounds to me like that could be solved with PPP's existing PAP or
CHAP authentication mechanisms to identify the device, to then decide
things like whether a /64 should be allocated.

If you don't want or need to actually authenticate the device via a
shared secret password, you just blindly accept whatever the supplied
password is. You'd be using the PPP authentication protocol really as
just a device identification protocol, and then use RADIUS to supply
whatever attributes to the BMS you want for that identified device.

Regards,
Mark.


> --
> Michael Richardson <[e-mail]>   . o O ( IPv6 IøT consulting )
>            Sandelman Software Works Inc, Ottawa and Worldwide