IPv6 linux-problem

[Keith Owens]

On Tue, 7 Nov 2000 09:12:08 +0100 (CET), 
Kristoff Bonne <kristoff.bonne@skypro.be> wrote:
>Does anybody know if the is a mailing-list or usenet-group for
>IPv6-related problems on linux?

linux-net is about the closest.

>In the mean while, here is already a question about my problem:
>Technical data:
>Toshiba Laptop (Satellite Pro 420CDT).
>Mandrake 7.1
>kernel: 2.2.15-4mdkfb (recompiled to enable IPv6)
>ethernet-card: Xircom CEM56 Ethernet/Modem (PCMCIA)
>
>When I boot the PC, everything is OK. I get a correct IPv6 address, the
>linux finds the router, and I am able to ping6 everything on the 6bone.
>
>But, after a while (about 5 to 10 minutes I guess), I cannot reach
>anything at all.
>Even a 'ping6' of my local IPv6-router doesn't work anymore ('Address
>unreachable', If I remember correctly).
>
>The only thing that helps is:
>- ifconfig eth0 down
>- ifconfig eth0 up
>(still nothing)
>- ping <IFv4-address of IPv6-router).
>
>(Remark: it's the IPv4 (!) address of router I must ping).

It sounds like your card is loosing its MAC filter, that is a common
problem with the Xircom cards.  IPv6 regularly looks at its local
environment, that requires multicast which makes the xircom driver
reload the MAC filter on the card.  There is a timing problem (which we
could never track down) where the load of the MAC filter silently
fails.  The result is that the card stops responding to packets.  This
problem is not just IPv6, it affects v4 as well.  I find that

 ifconfig eth0 -promisc; ping -c1 local-router

usually fixes my CBEM56G.  Switching out of promiscuous mode reloads
the MAC filter, even if the card was not promiscuous to start off with.