Re: RS sending in draft-ietf-v6ops-ipv6-cpe-router-04

[Philip Homburg <pch-v6ops@u-1.phicoh.com>]

In your letter dated Thu, 29 Apr 2010 18:03:08 +0200 you wrote:
> > If you come across a CPE that fails in some unspecified way (somebody asked
>  you
> > for help because the Internet is down or something like that) how do know
> > what is normal or not?
> 
> I would love to be able to tell SPs exactly how they should operate
> their networks. perhaps luckily for them I can't.

I think to some extent we are doing that. By setting standards.

> > Not all CPE have extensive debug interfaces where you dump all packets.
> 
> I would expect them to be able to show you the contents of received
> RAs though.

Sure? I never seen any of the low-end CPE device show the contents of a DHCP
or the PPP options that are negotiated. 

In a (be it experimental release) of a CPE with IPv6 stack you can't
figure out what DUID the device is using. 

> > If all links have global IP addresses then you know what is going on if you
> > find one that doesn't.
> 
> but that's not quite what you are advocating. an address from the
> delegated prefix is may be configured on the interface, but the
> prefix certainly wouldn't be on-link.

That's two separate issues. One is that I'd like to be able to assign a
subset of my prefix to the WAN link. The second issue is that ISPs seem to
create an almost endless variety of different way in which they implement
IPv6.


> > I don't know about the 'ND is used' part. But my ISP's router does not resp
> ond
> > to NS messages (on a PPP link). I think they believe that that's allowed by
> > the standards. Are you saying it isn't?
> 
> no. e.g NUD should be supported on any link, including PPP links.

I'll ask them. 

I think this an area where it may make sense to have some explicit text in
the CPE draft. Because even though by disabling ND my ISP seems to have broken
NUD, none the users ever discovered this or reported a problem. So it looks
as if every PPP implementation just assumes that there is no ND.