From: Stephen Hemminger <shemminger@vyatta.com>
To: Ben Hutchings <ben@decadent.org.uk>
Cc: 625914@bugs.debian.org, Noah Meyerhans <noahm@debian.org>,
bridge@lists.linux-foundation.org,
netdev <netdev@vger.kernel.org>
Subject: Re: [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4
Date: Mon, 9 May 2011 20:15:28 -0700 [thread overview]
Message-ID: <20110509201528.52d87ec4@nehalam> (raw)
In-Reply-To: <1304995124.4065.157.camel@localhost>
On Tue, 10 May 2011 03:38:44 +0100
Ben Hutchings <ben@decadent.org.uk> wrote:
> On Fri, 2011-05-06 at 13:12 -0700, Noah Meyerhans wrote:
> > Package: linux-2.6
> > Version: 2.6.38-3
> > Severity: normal
> >
> > Hi. I've got a system that hosts several kvm virtual hosts. The VMs
> > access the network via tap devices bridged with a physical interface.
> > After upgrading to linux-image-2.6.38-2-amd64_2.6.38-4, I noticed that
> > the virtualhosts were not autoconfiguring their IPv6 interfaces.
> > Debugging revealed that no multicast was passing over the bridge.
> >
> > The bridge configuration is:
> > bridge name bridge id STP enabled interfaces
> > br0 8000.0002e3080eb5 no eth1
> > tap0
> > tap1
> > tap2
> >
> > If I attach tcpdump to br0, I can see multicast (e.g. IPv6 Neighbor
> > Solicitation) packets. However, if I attach tcpdump to eth1, I do not
> > see multicast packets sourced from one of the VMs.
> >
> > Downgrading to 2.6.38-3 solves the problem.
>
> This is pretty weird. Debian version 2.6.38-3 has a few bridging
> changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> would cause this.
>
> Ben.
There are two possible explainations:
1. In 2.6.37 and kernels the bridge uses IGMP snooping, there were several
fixes to that in the stable kernel; especially related to IPv6.
2. There was also a recent change to block link local multicast
address. But that should impact what you are doing.
WARNING: multiple messages have this Message-ID (diff)
From: Stephen Hemminger <shemminger@vyatta.com>
To: Ben Hutchings <ben@decadent.org.uk>
Cc: Noah Meyerhans <noahm@debian.org>,
625914@bugs.debian.org, netdev <netdev@vger.kernel.org>,
bridge@lists.linux-foundation.org
Subject: Re: Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4
Date: Mon, 9 May 2011 20:15:28 -0700 [thread overview]
Message-ID: <20110509201528.52d87ec4@nehalam> (raw)
In-Reply-To: <1304995124.4065.157.camel@localhost>
On Tue, 10 May 2011 03:38:44 +0100
Ben Hutchings <ben@decadent.org.uk> wrote:
> On Fri, 2011-05-06 at 13:12 -0700, Noah Meyerhans wrote:
> > Package: linux-2.6
> > Version: 2.6.38-3
> > Severity: normal
> >
> > Hi. I've got a system that hosts several kvm virtual hosts. The VMs
> > access the network via tap devices bridged with a physical interface.
> > After upgrading to linux-image-2.6.38-2-amd64_2.6.38-4, I noticed that
> > the virtualhosts were not autoconfiguring their IPv6 interfaces.
> > Debugging revealed that no multicast was passing over the bridge.
> >
> > The bridge configuration is:
> > bridge name bridge id STP enabled interfaces
> > br0 8000.0002e3080eb5 no eth1
> > tap0
> > tap1
> > tap2
> >
> > If I attach tcpdump to br0, I can see multicast (e.g. IPv6 Neighbor
> > Solicitation) packets. However, if I attach tcpdump to eth1, I do not
> > see multicast packets sourced from one of the VMs.
> >
> > Downgrading to 2.6.38-3 solves the problem.
>
> This is pretty weird. Debian version 2.6.38-3 has a few bridging
> changes from stable 2.6.38.3 and 2.6.38.4, but they don't look like they
> would cause this.
>
> Ben.
There are two possible explainations:
1. In 2.6.37 and kernels the bridge uses IGMP snooping, there were several
fixes to that in the stable kernel; especially related to IPv6.
2. There was also a recent change to block link local multicast
address. But that should impact what you are doing.
next prev parent reply other threads:[~2011-05-10 3:15 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110506201234.6297.70279.reportbug@ip6-localhost>
2011-05-10 2:38 ` [Bridge] Bug#625914: linux-image-2.6.38-2-amd64: bridging is not interacting well with multicast in 2.6.38-4 Ben Hutchings
2011-05-10 2:38 ` Ben Hutchings
2011-05-10 3:15 ` Stephen Hemminger [this message]
2011-05-10 3:15 ` Stephen Hemminger
2011-05-10 4:38 ` [Bridge] " Noah Meyerhans
2011-05-10 4:38 ` Noah Meyerhans
2011-05-10 12:42 ` [Bridge] " Ben Hutchings
2011-05-10 12:42 ` Ben Hutchings
2011-05-10 12:55 ` Yann Dupont
2011-05-10 18:05 ` [Bridge] " Noah Meyerhans
2011-05-10 18:05 ` Noah Meyerhans
2011-05-10 22:11 ` [Bridge] " Stephen Hemminger
2011-05-10 22:11 ` Stephen Hemminger
2011-05-10 23:35 ` Noah Meyerhans
2011-05-10 23:35 ` Noah Meyerhans
2011-05-12 22:59 ` David Miller
2011-05-12 22:59 ` David Miller
2011-05-12 23:28 ` Stephen Hemminger
2011-05-12 23:28 ` Stephen Hemminger
2011-05-12 23:43 ` Stephen Hemminger
2011-05-12 23:43 ` Stephen Hemminger
2011-05-13 5:03 ` Noah Meyerhans
2011-05-13 5:03 ` Noah Meyerhans
2011-05-13 18:03 ` Stephen Hemminger
2011-05-13 18:03 ` Stephen Hemminger
2011-05-13 19:53 ` [Bridge] [PATCH] bridge: fix forwarding of IPv6 Stephen Hemminger
2011-05-13 19:53 ` Stephen Hemminger
2011-05-13 20:00 ` [Bridge] " Eric Dumazet
2011-05-13 20:00 ` Eric Dumazet
2011-05-13 20:02 ` [Bridge] " David Miller
2011-05-13 20:02 ` David Miller
2011-05-13 20:05 ` [Bridge] " Eric Dumazet
2011-05-13 20:05 ` Eric Dumazet
2011-05-13 20:24 ` [Bridge] " Stephen Hemminger
2011-05-13 20:03 ` David Miller
2011-05-13 20:03 ` David Miller
2011-05-13 21:00 ` [Bridge] " Noah Meyerhans
2011-05-13 21:00 ` Noah Meyerhans
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