[Dibbler] Address Autoconfiguration based upon Router Advertisement

[Tomasz Mrugalski]

On Tue, 9 Sep 2008 somebody known as Lalit Mishra wrote:

> RFC 2462 5.2 states that hosts should maintain variables ManagedFlag
> and  OtherConfigFlag on per interface basis. These flags describe the
> behavior of the host for stateful autoconfiguration mechanism.
> Accordingly if router advertisement on a link has ManagedFlag set  and
> the host is not already running the stateful address autoconfiguration
> protocol, the host should invoke the stateful address autoconfiguration
> protocol, requesting both address information and other information.
> (section 5.5.3).
>
> Is this behavior observed for dibbler 0.7.2 and linux kernel 2.6.13?
> When I run dibbler-client the machine acquires an address from the
> server running on the same link even if the router advertisement has
> ManagedFlag set. Is there some configuration changes required to make
> this work according to RFC?
No, that part is not implemented. Client asks for whatever is specified in 
the client.conf. There are several reasons behind that:
- I don't know how to check those bits (under Linux and various Windows
   flavors)
- When specifies that some options or addresses are to be configured, it
   would complicate things if client waited for RA and started after that.
   In other words, right now you can use DHCP without RA. With this change,
   you'd have to use them together.

Especially reason 2 is significant. It raises some questions: Is it 
possible to run DHCPv6 in a routerless network? In mobile environment, is 
it ok to start DHCP process before RA is received? If not, we are adding 
extra delays to the handover.

On the other hand, if you show me how to read those bits, I could 
implement support for them. A piece of code or patch would be appreciated.

Regards,
Tomek