On 23/12/2011 10:56, Chris Boot wrote:

On 23/12/2011 10:48, Nicolas de Pesloüan wrote:

quoted

[ Forwarded to netdev, because two previous e-mail erroneously sent in
HTML ]

Le 23/12/2011 11:15, Chris Boot a écrit :

quoted

On 23/12/2011 09:52, Nicolas de Pesloüan wrote:

quoted

Le 23 déc. 2011 10:42, "Chris Boot" <bootc@bootc.net
<mailto:bootc@bootc.net>> a écrit :

quoted

Hi folks,

As per Eric Dumazet and Dave Miller, I'm opening up a separate

thread on this issue.

quoted

I have two identical servers in a cluster for running KVM virtual

machines. They each have a
single connection to the Internet (irrelevant for this) and two
gigabit connections between each
other for cluster replication, etc... These two connections are in a
balance-rr bonded connection,
which is itself member of a bridge that the VMs attach to. I'm
running v3.2-rc6-140-gb9e26df on
Debian Wheezy.

quoted

When the bridge is brought up, IPv4 works fine but IPv6 does not.

I can use neither the
automatic link-local on the brid ge nor the static global address I
assign. Neither machine can
perform neighbour discovery over the link until I put the bond
members (eth0 and eth1) into
promiscuous mode. I can do this either with tcpdump or 'ip link set
dev ethX promisc on' and this
is enough to make the link spring to life.

For as far as I remember, setting bond0 to promisc should set the
bonding member to promisc too.
And inserting bond0 into br0 should set bond0 to promisc... So
everything should be in promisc
mode anyway... but you shoudn't have to do it by hand.

Sorry, I should have added that I tried this. Setting bond0 or br0 to
promisc has no effect. I
discovered this by running tcpdump on br0 first, then bond0, then
eventually each bond member in
turn. Only at the last stage did things jump to life.

quoted

quoted

This cluster is not currently live so I can easily test patches

and various configurations.

Can you try to remove the bonding part, connecting eth0 and eth1
directly to br0 and see if it
works better? (This is a test ony. I perfectly understand that you
would loose balance-rr in this
setup.)

Good call. Let's see.

I took br0 and bond0 apart, took eth0 and eth1 out of enforced
promisc mode, then manually built a
br0 with eth0 in only so I didn't cause a network loop. Adding eth0
to br0 did not make it go into
promisc mode, but IPv6 does work over this setup. I also made sure ip
-6 neigh was empty on both
machines before I started.

I then decided to try the test with just the bond0 in balance-rr
mode. Once again I took everything
down and ensured no promisc mode and no ip -6 neigh. I noticed bond0
wasn't getting a link-local and
I found out for some reason
/proc/sys/net/ipv6/conf/bond0/disable_ipv6 was set on both servers so I
set it to 0. That brought things to life.

So then I put it all back together again and it didn't work. I once
again noticed disable_ipv6 was
set on the bond0 interfaces, now part of the bridge. Toggling this on
the _bond_ interface made
things work again.

What's setting disable_ipv6? Should this be having an impact if the
port is part of a bridge?

Hmm, as a further update... I brought up my VMs on the bridge with
disable_ipv6 turned off. The VMs on one host couldn't see what was on
the other side of the bridge (on the other server) until I turned
promisc back on manually. So it's not entirely disable_ipv6's fault.

Hi,

I don't want this to get lost around the Christmas break, so I'm just 
resending it. I'm still seeing the same behaviour as before.

 From above:

quoted

quoted

quoted

For as far as I remember, setting bond0 to promisc should set the
bonding member to promisc too.
And inserting bond0 into br0 should set bond0 to promisc... So
everything should be in promisc
mode anyway... but you shoudn't have to do it by hand.

This definitely doesn't happen, at least according to 'ip link show | 
grep PROMISC'.

Chris

-- 
Chris Boot
bootc@bootc.net