RE: Posted a new copy of CPE Rtr draft

["Dan Wing" <dwing@cisco.com>]

> -----Original Message-----
> From: owner-v6ops@ops.ietf.org 
> [mailto:owner-v6ops@ops.ietf.org] On Behalf Of Stark, Barbara
> Sent: Friday, March 20, 2009 11:06 AM
> To: Hemant Singh (shemant); teemu.savolainen@nokia.com; 
> v6ops@ops.ietf.org
> Cc: Wes Beebee (wbeebee)
> Subject: RE: Posted a new copy of CPE Rtr draft
> 
> Another alternative, might be for the router to allow the its owner to
> put it in a bridged mode, instead of router mode. The "CPE 
> router" could
> still get its own IPv6 address from the WAN, as a host should. But all
> devices in the LAN would effectively just be hosts off the WAN, and
> there would be no real LAN. There would be no ULA either. The question
> is whether the design of the WAN would limit the number of hosts that
> could be given addresses across that one interface. If that were the
> case, then this wouldn't work, and the CPE router would be 
> forced to do
> a NAT66.

That would create a reliance on the ISP network for the in-home 
network to function.  It would be ashame if my security system,
IP-enabled television and Blu-Ray player, TiVo, NAS, etc., 
all break if the access link is down.

Perhaps to avoid that problem the router could get smarter and
hand out ULAs if it notices the WAN is down.  But that idea 
feels pretty fragile, too.

-d


> In many ways, this case is very similar to that of the cascaded router
> that isn't given a prefix.
> 
> I don't think this is a corner case.
> Barbara
> 
> -----Original Message-----
> From: owner-v6ops@ops.ietf.org [mailto:owner-v6ops@ops.ietf.org] On
> Behalf Of Hemant Singh (shemant)
> Sent: Friday, March 20, 2009 1:39 PM
> To: teemu.savolainen@nokia.com; v6ops@ops.ietf.org
> Cc: Wes Beebee (wbeebee)
> Subject: RE: Posted a new copy of CPE Rtr draft
> 
> Teemu,
> 
> If your SP does not dole out a PD to the CPE Rtr and as you say, your
> common case is just one /64 doled out to the WAN interface with PPP.
> Ok, so if your LAN interface(s) are assigned addresses using SLAAC,
> since SLAAC needs a /64, how can you possibly use the WAN's /64 to
> assign addresses to the LAN interface(s)?  It's not possible. 
>  Yes, you
> could run a DHCPv6 server in the device and then sub-delegate the /64.
> Hopefully such a DHCPv6 server sub-delegation is legal in IPv6
> standards...   
> 
> Alternatively, you can use ULA for the LAN and use the CPE Rtr as a
> router between WAN and LAN and not have anything to do with ND Proxy.
> 
> Hemant
> 
> -----Original Message-----
> From: teemu.savolainen@nokia.com [mailto:teemu.savolainen@nokia.com] 
> Sent: Friday, March 20, 2009 1:14 PM
> To: Hemant Singh (shemant); v6ops@ops.ietf.org
> Cc: Wes Beebee (wbeebee)
> Subject: RE: Posted a new copy of CPE Rtr draft
> 
> Thanks for quick reply, I was ok with other things than this one:
> 
> >- 7.1. In 3GPP case the /64 prefix is not only for LAN 
> >interfaces, but also for the WAN interface. Thus I'd rather 
> >say:".. across multiple LAN interfaces, possibly including WAN 
> >interfase as well, and the CPE router..". Then "..any two LAN 
> >interfaces.." -> "..any two interfaces..". And still later 
> >"..if any two disparate LAN interfaces..." -> "..if any two 
> >disparate interfaces..".
> >
> ><hs>
> >Disagree. You are suggesting one implement ND Proxy between 
> >the WAN and LAN interfaces.  For the CPE Rtr, the WAN and LAN 
> >interface(s) are two different routing domains - if one can 
> >perform routing between domains, why support ND Proxy?  We are 
> >also making the last sentence better in section 7.1 as follows:
> 
> Yes. That is what has to be done in the link types we have to 
> support. I
> don't see any other way when there is just single /64 received from
> point-to-point WAN interface (in RA) which has to be enough for
> numbering the "CPE" itself and all the devices in Ethernet LAN behind.
> Please let me know if there is a better way.
> 
> Only alternative I see is to have NAT66 in CPE similar to IPv4 NAT we
> already have to share the single IPv4 address we get from operator.
> 
> It would be very nice if there would be DHCPv6 PD available 
> for "CPE" to
> ask for prefixes for LAN, but unfortunately that is not 
> always the case.
> 
> I think we discussed this in IETF#73 corridor, but I have forgotten
> details... So maybe I should write a link-type specific 
> document, which
> would describe this behaviour (maybe corner-case from IETF point of
> view, but the most important use-case from my point of view)? 
> After all,
> I guess it is better to describe it rather than have it just as
> implementation-specific design choice?
> 
> Best regards,
> 
> 	Teemu (I will not be able to make the v6ops meeting as I have to
> be in shara BOF)
> 
> 
> *****
> 
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