[support] Destination unreachable from HA on BU???

[Mattias Blomqvist]

Hi,

On Fri, Mar 27, 2009 at 9:40 AM, Arnaud Ebalard <arno at natisbad.org> wrote:
> Hi,
>
> Well, *in that case*, what UMIP does is quite logical. You should never
> have the HoA configured automatically or statically on the system. UMIP
> will handle the HoA which will be assigned to the ip6tnl* interface.

Aha! Ok. It works a little bit better now.

>>> - If a RA is received, it is not processed by UMIP, i explicitly
>>>  prevented that in the code for tunnel ifaces, so even if an
>>>  unsollicited RA is received, then, UMIP is not the one that will set
>>>  the address on the tunnel interface. Does a userland process does
>>>  that?
>>
>> No. The kernel process the RA like it would for any other interface
>> and sets the address according to how it should be done for stateless
>> autoconfig.
>
> I checked the code and remembered I decided not to touch the existing
> /proc configuration for a Tunnel interface when I wrote the code. In
> process_new_inet6_iface(), I added those lines for that purpose.
>
>                        if (!iface->is_tunnel)
>                                iface_proc_entries_init(iface);
>
> This explains why the kernel does it job on this specific iface.

Not entirely true regarding the /proc configuration. The /proc
configuration default (/proc/sys/net/ipv6/conf/default/*) is still set
last in md_init() by a call to iface_default_proc_entries_init(). This
means that when the tunnel interface is created it will inherit the
defaults already set by mip6d. This is mainly a problem for accepting
default router routes in RA's (the default for autconf is set to 1).
This is however not really a problem. I will handle it in the
user-space process handling the tunnel interface.



One additional problem seems to be that the tunnel interface must
exist when mip6d is started. Is there any way around this?


BR,
Mattias