Linux Ethernet Bridging - Feb 2015 - [Bridge] bride: IPv6 multicast snooping enhancements

On 10.02.2015 14:44, Linus L?ssing wrote:
> Hi Vasily,
> 
> On Tue, Feb 10, 2015 at 11:44:29AM +0300, Vasily Averin wrote:
>> This patch prevent forwarding of ICMPv6 in bridges,
>> so containers/VMs with virtual eth adapters connected in local bridge
cannot ping each other via ipv6 (but can do it via ipv4)
> 
> If a host wants to receive packets, then it needs to signalize
> that via MLD. If your host does not do that, then it is expected
> to not receive ICMPv6 echo requests to multicast addresses. An
> exception is ff02::1, that should always work.
Thank you for explanation, seems now I understand finally how it should work.

I'm trying to fix ICMPv6 processing broken in OpenVZ after rebase to last
RHEL6u6 kernel.
After some unclear manipulation bridge begins to forward icmp6 NS (fe02::1) into
wrong port,
and at present I do not found the reason of this failure.

Thank you,
	Vasily Averin

On Tue, Feb 10, 2015 at 04:59:09PM +0300, Vasily Averin
wrote:
> I'm trying to fix ICMPv6 processing broken in OpenVZ after rebase to
last RHEL6u6 kernel.
> After some unclear manipulation bridge begins to forward icmp6 NS (fe02::1)
into wrong port,
> and at present I do not found the reason of this failure.
fe02::1 seems uncommon for ICMPv6 NS messages. Would you mind
making some dumps for ~10 minutes with tcpdump on all bridge ports
and the bridge interface itself with a filter "icmp6" and uploading
the
result somewhere?

Also provide a dump from "bridge mdb show dev $bridge" please (if
possible - not sure whether that's available on the ancient 2.6.32
kernel as used on RHEL6u6).

Cheers, Linus