IPv6 autoconfiguration on a multihomed site

[Juan Rodriguez Hervella]

On Thursday 02 October 2003 17:04, SUZUKI Shinsuke wrote:
> Hello Juan,
>
> >>>>> On Tue, 30 Sep 2003 09:42:39 +0200
> >
> > Address of Router1: 2001:720:410:100b::3
> > Address of Router2: 2001:800:40:2471::4
>
> Please confirm connectivity from Router2 to Router1 by the following
> command.
> 	Router2% ping6 -S 2001:720:410:100b::3 2001:800:40:2471::4

Though I don't know how to select the source address on the ping
command on the CISCO, I tell you that *doesn't* work (without -S).

I've got a default route towards the upstream provider that this
router is connected to, so if I sends packets to 2001:800:40:2471::4
those will be routed outside my site because this router doesn't
belong to the 2001:800:40:2471::/64 network (it is the router that
announces 2001:720:410:100b::/64).


>
> If it does not work, it's no wonder that you cannot ping from PC to
> Router1 when the PC's default router is router2.  The simplest fix for
> this problem is to assign 2001:720:410:40::/64 and
> 2001:800:40:2471::4/64 to both routers:
> 	Address of Router1: 2001:720:410:100b::3, 2001:800:40:2471::3
> 	Address of Router2: 2001:720:410:100b::4, 2001:800:40:2471::4
>

If I do that, then everything is fixed.
(I suppose that the first time I send sth. to router1 from the host, 
it will be route, for example, to router2, which will realize that 
the packet belongs to the other router, making something like a 
triangular routing, at least the first time, because afterwards a redirect 
message should be sent, right ?)

But I think this isn't the way the problem should be fixed, I mean,
why a router which only announces one prefix has to be configured with
the prefix of another router ? In this scenario, the hosts should behave in
the same way as with only one prefix. For example, if there's only one
prefix, the host doesn't send packets to the default router, it sends them
directly on the link...I don't understand why the same thing can not be
applied when there are *two or more* links... where's the 
limitation ? or do you think that this is the way things should be running ?
(Windows XP SP1 behave alike, though this isn't a relief :)

> If you cannot still ping from PC to Router1 although it works, please
> show me the routing tables of both routers.
>
> Thanks,

My *thanks* for you all, you're doing a great job!
(I'm applying to visit Japan some day *lol*, just kidding...
I've seen on the telly that there are earthquakes !!)

> ----
> SUZUKI, Shinsuke @ Hitachi / KAME Project

-- 
JFRH