IPv6 network policies

[Mark Smith]

On Sun, 11 Apr 2010 08:32:08 +0200
Ole Troan <otroan at employees.org> wrote:

> >> NUD could be done, but on most router to router links it is
> >> unnecessary and not used.
> >> 
> > 
> > I suppose this comes down to if you don't agree with (or maybe just
> > don't fully understand) the way something works in an RFC, does that
> > mean it's ok for you not to implement it the way the RFC says?
> 
> good to hear that you are the authority on how RFC4861 should be read (note this may be sarcasm. ;-)).
> please point us to the sections in RFC4861 which require an implementation to do address resolution on a link without L2 addresses. and if it is not address resolution, which part of ND are you referring to?
> 

I've quoted the sections of that RFC (and it's ancestor) twice to this
thread already that support this view. I've also looked through the ND
RFCs for any statements that specifically refer to the operation of ND
over P2P links, and what is optional. I can't find any.

It's well known that the pong pong problem doesn't exist if ND
NS/NAs are used.

The IPv6 PPP spec negotiates 64 bit IDs for ends of links. As P2P links
only have two attachments, then I think that also supports /64s per PPP
link, and therefore ND NS/NA. As the PPP RFC does deal with neighbor
discovery issues (i.e. the DAD clauses) I'd expect it'd also specify
that ND NS/NAs could be switched off, if that was allowed. It doesn't.

The IPv6 Node Requirements RFC doesn't make a special case of P2P
links in it's Neighbor Discovery section.

The only (Informational) RFC I can find that refers to running IPv6
over SONET (i.e. the case people commonly refer to when pointing out
the ping pong problem), RFC3572 - "Internet Protocol Version 6 over
MAPOS (Multiple Access Protocol Over SONET/SDH)", does not state that
it is acceptable to not perform NS NS/NAs. It does specify the use of
EUI-64s instead of MAPOS link layer addresses, which naturally
implies /64 assignment. As people commonly run PPP over SONET anyway,
whatever the IPv6 PPP RFC says about ND operation is applicable.

I'm yet to have anybody provide a reference to text in any RFC that
says this "optimisation" is allowed. I made that invitation quite a
number of emails ago. If such text exists, I'd like to read it. The
invitation to provide it is still open. The sooner I can find out I'm
wrong, the sooner I'll be right. But I won't just take people's
opinions to change mine, because I've been burnt enough in the
past taking peoples' statements at face value.

(Here's an example. If you want to create a static sink route on
a Cisco router, can you use an Admin Distance of 255?)

> references to the ipng mail archive would also be appreciated.
> 

Aren't RFCs supposed to be authoritative?

Regards,
Mark.