Unique IPv6 Prefix per Host
RFC 8273

Radius should have an informative reference on first use.

Thanks for addressing my DISCUSS point.

Thanks for addressing my previous comments.

Two nits:
- Lorenzo: https://mailarchive.ietf.org/arch/msg/v6ops/EbF-7q17N9qy8N4KV2mOMuMY9YY (emphasise the multi addressing)
- Tim: https://mailarchive.ietf.org/arch/msg/v6ops/Fu-b--IA3NkbgvmXET1tygeF920 (should 7217 be mentioned not just old 4862 SLAAC, and on consistency between 8106 and stateless DHCPv6)

I trust the responsible AD's judgement to evaluate if those editorial changes are important enough.

Regards, Benoit

Document: draft-ietf-v6ops-unique-ipv6-prefix-per-host-07.txt


I found the discussion of the shared network medium a bit
confusing. As I understand it, the idea is that if we are
on a shared network and we have the same prefix, I might
try to send to you directly. What you want to do is make
that not happen by having each node have a separate prefix.
Correct? If so, perhaps promote this bullet, and also have
it describe the problem and why this provides a solution:

   o  Two devices (subscriber/hosts), both attached to the same provider
      managed shared network should only be able to communicate through
      the provider managed First Hop Router


It's a bit unclear to me how much you are saying that
something is current practice versus how much you are
recommending it. For instance, the abstract reads more
like what you would expect for PS.

   This document outlines an approach utilising existing IPv6 protocols
   to allow hosts to be assigned a unique IPv6 prefix (instead of a
   unique IPv6 address from a shared IPv6 prefix).  Benefits of unique
   IPv6 prefix over a unique IPv6 address from the service provider
   include improved subscriber isolation and enhanced subscriber
   management.

But then S 4 seems to be documenting:

   The IPv6 RA flags used for best common practice in IPv6 SLAAC based
   Provider managed shared networks are:


   The use of a unique IPv6 prefix per UE adds an additional level of
   protection and efficiency as it relates to how IPv6 Neighbor
   Discovery and Router Discovery processing.  Since the UE has a unique
   IPv6 prefix all traffic by default will be directed to the First Hop
   provider router.  Further, the flag combinations documented above
   maximise the IPv6 configurations that are available by hosts
   including the use of privacy IPv6 addressing.

It's not quite clear to me why unique prefixs are needed here if
people set L=0. Is it that people ignore L=0?

Finally, I'm a bit confused about how to read this text about the
L=0 bit in cases where I have multiple devices rather than just one
at the customer prem. Say I have a topology with a home router
and devices behind it. I.e.,

                    Service Provider
                           |
                           |
                        Customer
                         Router
                           |
               +-----------+-----------+
               |           |           |
             Host 1      Host 2      Host 3

I assume what happens here is that the router gets prefix X, assigns
itself XY, and then the Hosts get XA, XB, XC, etc, a la 7278. Is that
right? If so, my question is about packets coming into the Router from
the SP, which have (say) XA.  The text about the L-flag suggests that
the router should send them back to the gateway, but that's clearly
not right. What am I missing?

Thank you for addressing the SecDir review:
https://mailarchive.ietf.org/arch/msg/secdir/wWp_0vlmsz7Ss-nowjhehYImOeg

To me this seems approriate for BCP; I'm saying this because this was mentioned in the shepherd-write-up as it was brought up by the gen-art review.

Please also consider the following comment from the gen-art review (Thanks Joel!):
"The issue of status for the document (BCP vs Informational) is for the IESG
   to conclude.  However, even if it is a BCP, as I understand the purpose,
   this document is intended to describe the practices to be used when a
   provider has decided to deploy a /64 per host.  The wording that is chosen
   throughout the document makes it appear that the underlying decision about
   such a deployment is also a recommended practice."
I agree that wording could be made clearer here!

One nit:

Please consider moving 

   Benefits of unique
   IPv6 prefix over a unique IPv6 address from the service provider
   include improved subscriber isolation and enhanced subscriber
   management.

to the first paragraph of the Abstract. I’m assuming that this explains the “needs that have arisen” in the first sentence of the Abstract, of course.