Re: virbr0/bridge: No such file or directory, rhel6 bridge-utils IGMP snooping

["Pasi Kärkkäinen" <pasik@iki.fi>]

On Fri, Aug 26, 2011 at 04:54:34PM +0300, Pasi Kärkkäinen wrote:
> On Fri, Aug 26, 2011 at 02:25:57PM +0300, Pasi Kärkkäinen wrote:
> > On Fri, Aug 26, 2011 at 01:13:14AM -0500, Scott Meyers wrote:
> > > 
> > > This is fresh install of CentOS v6 and Xen v4.1 on a new Dell server following the tutorial posted at: http://wiki.xensource.com/xenwiki/RHEL6Xen4Tutorial
> > >  
> > > Every thing went just fine, yet virbr0 won't work and when I run brctl show I get the following error message:
> > >  
> > > [root@pe1950 ~]# brctl show
> > > bridge name     bridge id               STP enabled     interfaces
> > > virbr0          /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > /sys/class/net/virbr0/bridge: No such file or directory
> > > 8000.000000000000       yes
> > >  
> > > FYI, /sys/class/net/virbr0/bridge does exist. That said I can't install any DomU because virbr0 is down/not working.
> > >  
> > > I read all threads about this problem, but none gave any solutions. Please help. Thank you
> > >  		 	   		  
> > 
> > 
> > Those errors are related to the bridge-utils rpm version..
> > There is a workaround documented somewhere.. probably on centos mailinglist.
> > 
> 
> or actually it's because the stock rhel6 kernel includes some patch to 
> kernel bridging code so rhel6 bridge-utils rpm had to be patched for the kernel change.
> 
> so when you use xen.git 2.6.32 kernel (which is not based on rhel6 kernel) you don't have
> the kernel change for bridging and the patched bridge-utils rpm doesn't work anymore.
> 
> Try using mayoung's el6 xendom0 kernel rpm.. it *is* based on rhel6 kernel so it includes the bridging patch.
> 

The bridging problem and the fix is discussed here:
http://lists.xensource.com/archives/html/xen-devel/2011-02/msg00760.html

Problem is Redhat added IGMP snooping support to rhel6-kernel,
so they had to patch bridge-utils aswell, but the vanilla Linux 2.6.32
does not have igmp-snooping so when you use mainline 2.6.32 or xen/stable-2.6.32.x
with the rhel6 bridge-utils you get those errors.

-- Pasi