(usagi-users 00549) routing / redirect messages

[Remco van de Meent <remco@xxxxxxxxxxxxxx>]

Hi,

I've got a network with hosts and routers, over which I have limited
control. I do have full control over the default router.

The problem I'm facing has to do with routing throughout this network.
Let me first explain the situation with a drawing that depicts a small
part of the network:

               IPv6 world
                   |
                   r (default router)
                   |
                   |
-------------------^----------------- prefix::/64 network
|    |	  |	|    |    |    |    |
h    r    h     h    r    h    h    r
     |               |              |
   --^--           --^--          --^-- prefix:something::/112 networks
   | | |           | | |          | | |
   h h h	   h h h          h h h


On this network, we have one big /64 prefix. However, some of the hosts
in this network want to act as a router for other (small) network
connected to it. These networks will get a /112 out of the /64 range.
The default router knows which /112 is network via what host (router).

So far so good. However, now if hosts in one of the /112 networks want
to communicate with other hosts in the /64 or another /112 network, we
have routing problems, unless every host and router in the /64 network
has "full routing" information with regard to the entire /64 range. Due
to scalibility problems, this is not an option. As the "/112 routers"
are part of the /64 network, hosts in that network won't go to the
default router if they want to send to a "/112 host". Neighbor
discovery just fails (for that reason).

I'm currently looking for a solution to this problem. I've been
thinking of using neighbor discovery redirect messages, sent out by the
default router, when a host in the /64 network is trying to reach a
host in one of the /112 networks. 

Something like that should work, right?  If so, does the USAGI Linux
IPv6 stack provide such services? 

Thanks for your help and information.


cheers,
Remco.