Re: [Softwires] MAP compatibility with DS-Lite

[Wojciech Dec <[e-mail]>]

Now, how about this to move things forward: We replace the quoted
text/section with the following added into section 5.4

"A MAP-E CE provisioned with only the IPv6 address of the BR MUST
   disable its NAT44 functionality and treat the point-point tunnel
interface as active for IPv4 forwarding."

In case we want to proceed with the argument, it is continued inline...

On 25 November 2013 13:39, Ole Troan <[e-mail]> wrote:

> Wojciech,
>
> > You're apparently missing some key points:
>
> that's not uncommon. ;-)
>
> > 1.  It's a functional requirement of a CPE, specifying how the CPE
> behaves with a case of NOT having an IPv4 address. What is the to be the
> bahviour of a MAP CPE without one?
>
> just like if it didn't get an IPv4 address on native Ethernet.
>

Now, the way MAP's forwarding rules have been modelled, the IPv4 default
route follows the IPv6 BR address. Hence, the presence of the IPv6 address
equates to the presence of a v4 default route, accessible via the tunnel to
the BR. In none of the v4 auto tunneling technology in use here is it a
requirement for the tunneling router to have some operator assigned IPv4
address on an interface to be able to forward packets on it.



>
> > 2.  This is NOT about configuring a ds-lite CPE
>
> my understanding was that the CPE had to be provisioned for this mode,
> possibly as a separate MAP domain. and that the BR must also act as a CGN.
>

One doesn't need a DS-Lite CPE to be able to send IPv4inIPv6.

>
> > Throughout, its still not been answered what is the downside of having
> this functionality of a *MAP CPE*?
>
> it adds yet another variant.
> what's wrong with provisioning the DS-lite option when you want this
> behaviour?
>

Is DS-Lite required to configure a MAP CPE, or to enable IPv4inIPv6 on a
router?


> or if you want overflow from MAP to DS-lite?
>

I didn't bring up overflow - not sure why you added it.


>
> I don't get the benefit of what you are suggesting.
>

Clearly, but there are multiple as mentioned (not least, the ability for
the operator to actually turn off NAT44  on the user's CPE for t'shooting
purposes).

Cheers,
Wojciech.


> cheers,
> Ole
>