RE: Comments on draft-wbeebee-ipv6-cpe-router-01.txt

["Hemant Singh (shemant)" <shemant@cisco.com>]

The traffic direction of the Loopback interface in the generic router
sense is that the Loopback interface does not face any traffic
direction.  However, the Loopback interface for the CPE Router can
initiate IPv6 address acquisition via the WAN interface to the SP.  

The architecture, I am referring to is Integrated Routing and Bridging
(IRB) - google it.  Such routing can send the RA to other virtual
interfaces of a router.

Hemant

-----Original Message-----
From: Francois-Xavier Le Bail [mailto:fx.lebail@yahoo.com] 
Sent: Monday, July 21, 2008 11:06 AM
To: Hemant Singh (shemant)
Cc: Iljitsch van Beijnum; Ole Troan; IPv6 Operations
Subject: RE: Comments on draft-wbeebee-ipv6-cpe-router-01.txt

Yesterday you said  "Also, the virtual Loopback interface is in the same
link-local domain as the WAN interface."

Today you say "The Loopback interface doesn't face the downstream or the
upstream."

Can explain clearly your architecture?

Francois-Xavier

--- On Mon, 7/21/08, Hemant Singh (shemant) <shemant@cisco.com> wrote:

> From: Hemant Singh (shemant) <shemant@cisco.com>
> Subject: RE: Comments on draft-wbeebee-ipv6-cpe-router-01.txt
> To: "Ole Troan" <otroan@employees.org>
> Cc: "Iljitsch van Beijnum" <iljitsch@muada.com>, "IPv6 Operations" 
> <v6ops@ops.ietf.org>
> Date: Monday, July 21, 2008, 7:31 AM
> We are not even concerned about the draft being a WG work item.  We 
> have not even completed requirements for the device.
> 
> > no, you cannot use stateless DHCP for prefix
> delegation.
> 
> Also, if you say IA_PD is forbidden by stateless DHCPv6, please point 
> to a MUST NOT text in any RFC.
> 
> > e.g:
> > - false: downstream interfaces (loopback, LAN) can run
> SLAAC or DHCP
> IA/PD protocols
> 
> The Loopback interface doesn't face the downstream or the upstream.  
> You and I both know RFC3633 has no explicit text that prohibits 
> stateless
> DHCPv6 asking for IA_PD as I showed how (using the ORO once an 
> interface has acquired a global IPv6 address).
> 
> > - false: you need a global address on the WAN
> interface for uRPF
> 
> If you don't see the obvious problem with uRPF with just a link-local 
> address on the WAN interface, I suggest you go do a test and get back 
> to us.
> 
> > - false: loopback interface is required. (it's
> only purpose is to have
> a stable always up management interface).
> 
> DSL folks have asked to support the WAN interface acquiring a 
> link-local address.  So it is the Loopback interface that acquires a 
> global IPv6 address to source packets to the WAN.  If the Loopback 
> interface is not spawned, then since the LAN interface has global IPv6

> address, one could say, use the LAN interface global address to source

> packets to the WAN.
> But the CPE Router will not even function if the WAN interface has 
> only link-local and the LAN interface has a global IPv6 address
> - see section
> 4 of
> 
> http://www.ietf.org/internet-drafts/draft-miyakawa-1plus64s-00.txt
> 
> 
> Hemant
> 
> -----Original Message-----
> From: ichiroumakino@gmail.com
> [mailto:ichiroumakino@gmail.com] On Behalf Of Ole Troan
> Sent: Monday, July 21, 2008 6:54 AM
> To: Hemant Singh (shemant)
> Cc: Iljitsch van Beijnum; IPv6 Operations
> Subject: Re: Comments on
> draft-wbeebee-ipv6-cpe-router-01.txt
> 
> Hemant,
> 
> > For Iljitsch van Beijnum related to his question on
> whether IA_PD
> > could be asked of by stateless DHCPv6:
> >
> > Sorry one correction for this statement in the email
> below.
> >
> > "The Loopback interface would need to acquire a
> global IPv6 address
> > first using stateful DHCPv6 (a MUST, because SLAAC
> doesn't support
> > getting IA_PD).(a MUST, because SLAAC doesn't
> support getting IA_PD)."
> >
> > The Loopback interface may acquire the global IPv6
> address using SLAAC
> 
> > and not necessarily DHCPv6.  Then since the Loopback
> interface does
> > have a global address, then I believe it is
> permissible for stateless
> > DHCPv6 to get IA_PD by specifying the IA_PD option in
> the ORO?  We
> > need to check if RFC3633 explicitly prohibits asking
> for IA_PD by
> > stateless DHCPv6? Ole, what say you - thanks?
> 
> no, you cannot use stateless DHCP for prefix delegation.
> 
> I don't understand where you are going with this draft.
> this is all over
> the map. several people on this mailing list has tried to correct your

> misconceptions, but we don't seem to be getting through...
> 
> e.g:
> - false: downstream interfaces (loopback, LAN) can run SLAAC or DHCP 
> IA/PD protocols
> - false: you need a global address on the WAN interface for uRPF
> - false: loopback interface is required. (it's only purpose is to have

> a stable always up management interface).
> 
> > Anyhow, the problem still remains that we expire the
> SLAAC address and
> 
> > then reassign an address from IA_PD. Same old
> ugliness.
> 
> huh? don't understand this.
> 
> I would not support this draft to become a working group document.
> 
> /ot