Re: IPv6 autoconfig only in promisc mode?

From: Pekka Savola (pekkas@netcore.fi)
Date: Fri May 09 2003 - 16:04:06 EST


On Fri, 9 May 2003, Beat Bolli wrote:
> Recently I was testing a 6to4 setup involving a gateway and a
> laptop behind the gateway. I installed radvd on the gateway and
> configured it to announce the tunnel running over eth1 on
> interface eth0.
>
> On the laptop, I just modprobed ipv6 and watched ifconfig's output
> to see it it automatically got a scope:global address. As it didn't
> get one after a minute or so, I started tcpdump in a second terminal
> to check if radvd was in fact advertising the tunnel. Well, big was
> my surprise when right after the next advertisement the global address
> appeared, and it was even bigger when it disappeared again 5 minutes
> after I had terminated tcpdump. Then I did another check with
>
> ifconfig eth0 promisc; sleep 60; ifconfig eth0 -promisc
>
> and the behaviour way exactly the same. It seems like the kernel can
> see the router advertisements only if the interface is in promiscuous
> mode. Is this by design, is it just not finished yet, or am I missing
> something completely here? Would the tcpdump output be helpful?

I've seen the same on a laptop: I think this is a driver bug.

Which driver/card do you have?

Have you tried using "allmulti" flag instead of promisc? That should
help IIRC.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html



This archive was generated by hypermail 2b29 : Thu May 15 2003 - 22:00:00 EST