Subject: Re: [IPV6] addrconf: Fix IPv6 on tuntap tunnels

From: Vlad Yasevich <[email-masked]>
Date: Mon, 18 Jun 2007 13:56:26 -0400

Herbert Xu wrote:
> On Fri, Jun 15, 2007 at 03:14:57PM -0700, David Miller wrote:
>>> No, the questions should really be:
>>>
>>> 1.  Is IPV6 supported over this media type.
>>> 	yes: got to 2
>>> 	no:  stop
>>>
>>> 2.  Is the device MTU >= IPV6_MIN_MTU
>>> 	yes: continue
>>> 	no:  stop
>>>
>>> Autoconfiguration is a layer on top of IPv6.  Whether it's enabled
>>> or not should not dictate whether IPv6 addressed may be configured or not.
>> Sounds good to me, patches? :-)
> 
> I don't think we need any more patches since right now MTU >= IPV6_MIN_MTU
> is the only condition we require before we allow IPv6 addresses to be added
> to an interface.
> 
> The original patch simply confused this basic IPv6 address support with
> IPv6 autoconfiguration.

Looking over the history, Herbert has mostly right.

The only concern I have is that it's currently permitted to configure
IPv6 addresses on interface that would not have link-local addressing
(ex: IEEE 1394 link).

Now, is some circumstances that's ok (tuntap is a perfect example).
In others, particularly where there is an "IPv6 over foo" spec, not so much.

-vlad