Re: [mif] Route option for DHCPv6 - next steps?

[Lorenzo Colitti <[e-mail]>]

On Tue, Apr 24, 2012 at 16:52, Alexandru Petrescu <
[e-mail]> wrote:

> Why? The Linux Kernel supports RFC 4191, for example.
>>
>
> Yes, linux kernel would support it, as a Host.  The CPE is not a Host.
> (yes, a flag may exist to force it be a Router _and_ listen to RA - but
>  is that flag standard).


For the kernel, I believe all you need to do is enable forwarding
separately on the upstream and downstream interfaces instead of enabling
forwarding globally (but I'm not 100% sure so feel free to correct me if
that's wrong). That said, regardless of how it needs to be implemented,
Linux-based CPEs have to do it already if they implement RFC 6204.


>    If one wants to deliver specific routes to a CPE box one would't use
>>>    RAs, because routers ignore much of info in them.
>>>
>>>
>> RFC 6204 specifies how IPv6 CPEs should listen to default routes in
>> router advertisements. The CPEs could listen to more-specific routes as
>> well.
>>
>
> This may mean one may need to: (1) modify RFC6204 to cover specific routes
> as well, (2) modify RFC4191 to cover Routers as well, (3) modify RFC6204 to
> do cellular base stations as well, in addition to CPE of ADSL-type.
>

As for #1 and #2, RFC 6024 doesn't explicitly specify what CPEs should
listen to in RAs. I mentioned the default route earlier, but it mentions
lots of other things too (e.g., the prefix information option to do SLAAC
on the ISP-side interface, the L bit, and so on). If the CPE doesn't
already support RFC 4191 (which is possible, if it's just using the
standard Linux code), then it needs a code change regardless of whether you
want to use DHCPv6 or RFC 4194.

As for #3: RFC 6204 doesn't specify any specific technology, and it's
certainly not limited to ADSL. Much of the behaviour it specifies is
equally applicable to CPEs whose uplink is a cellular link.