Xen users - Jun 2012 - [XEN][Ubuntu's Linux bridge replaced by OVS problem using XEN]

Hi,
I have two systems(a laptop and a desktop) connected with an Ethernet
cable. Desktop is using the Internet through the laptop wireless LAN.
Both systems have Ubuntu 11.10 with XEN 4.1.2 Hypervisor. I have compiled
OpenvSwitch-1.5 on both the systems as well. In Linux Bridge mode both can
ping each other.


Problem:
LINUX bridge is used in both systems and both can access the internet but
as soon as I replace the Linux bridge with OVS, Desktop can no more access
the Internet. Connection is lost between the two nodes. Also both systems
can not ping each other under OVS.

Regards,
Waqar Ahmed


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On Wed, Jun 27, 2012 at 6:31 PM, Waqar Ahmed <waqar.ahmed@sysnet.org.pk>
wrote:
> Hi,
> I have two systems(a laptop and a desktop) connected with an Ethernet
cable.
> Desktop is using the Internet through the laptop wireless LAN.
> Both systems have Ubuntu 11.10 with XEN 4.1.2 Hypervisor. I have compiled
> OpenvSwitch-1.5 on both the systems as well. In Linux Bridge mode both can
> ping each other.
>
>
> Problem:
> LINUX bridge is used in both systems and both can access the internet but
as
> soon as I replace the Linux bridge with OVS, Desktop can no more access the
> Internet. Connection is lost between the two nodes. Also both systems can
> not ping each other under OVS.
Have you used OVS on ANY configuration at all? e.g. non-xen?

If not, then that might be the source of your problem. Get ovs working
first (e.g. with kvm, virtualbox, whatever).

If yes, then probably you''re using the obsolete xen''s
network-bridge
script. Disable that, and create your bridges manually using ovs.

-- 
Fajar

Thank you Fajar, No I have never used OVS on any configuration.
I am following the INSTALL.LINUX and INSTALL.BRIDGE to insert the OVS as a
kernel module in XEN booted kernel on Ubuntu 11.10. I do remove the Linux
bridge to get OVS working.
I am still working on it and will reply once i get something significant

On Wed, Jun 27, 2012 at 5:02 PM, Fajar A. Nugraha <list@fajar.net> wrote:
> On Wed, Jun 27, 2012 at 6:31 PM, Waqar Ahmed
<waqar.ahmed@sysnet.org.pk>
> wrote:
> > Hi,
> > I have two systems(a laptop and a desktop) connected with an Ethernet
> cable.
> > Desktop is using the Internet through the laptop wireless LAN.
> > Both systems have Ubuntu 11.10 with XEN 4.1.2 Hypervisor. I have
compiled
> > OpenvSwitch-1.5 on both the systems as well. In Linux Bridge mode both
> can
> > ping each other.
> >
> >
> > Problem:
> > LINUX bridge is used in both systems and both can access the internet
> but as
> > soon as I replace the Linux bridge with OVS, Desktop can no more
access
> the
> > Internet. Connection is lost between the two nodes. Also both systems
can
> > not ping each other under OVS.
>
> Have you used OVS on ANY configuration at all? e.g. non-xen?
>
> If not, then that might be the source of your problem. Get ovs working
> first (e.g. with kvm, virtualbox, whatever).
>
> If yes, then probably you''re using the obsolete xen''s
network-bridge
> script. Disable that, and create your bridges manually using ovs.
>
> --
> Fajar
>

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Xen-users@lists.xen.org
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On Fri, 29 Jun 2012 10:21:40 +0500
Waqar Ahmed <waqar.ahmed@sysnet.org.pk> wrote:
> Thank you Fajar, No I have never used OVS on any configuration.
> I am following the INSTALL.LINUX and INSTALL.BRIDGE to insert the OVS
> as a kernel module in XEN booted kernel on Ubuntu 11.10. I do remove
> the Linux bridge to get OVS working.
> I am still working on it and will reply once i get something
> significant

I have been using this for quite some time.

In xen-network-common.sh you can find the add_to_bridge function. Here
you find the line ''brctl addif ${bridge} ${dev}''. Simply
replace this
with ''ovs-vsctl add-port ${bridge} ${dev}''.

If you want to assign the device to a VLAN from your VM config you can
do that too. Openvswitch can create "fake bridges" that are VLAN
tagged
and you can add interfaces to that fake bridge.

Example:

# Create virtual bridge
ovs-vsctl add-br vbr0

# Create a fake bridge connected to vbr0 with tag 10
ovs-vsctl add-br vbr0 vlan10 10

# Add a device that gets tagged with tag 10
ovs-vsctl add-port vlan10 vm1


So, in your VM''s vif line this translates to:
script=vif-bridge,vifname=vm_foo0,mac=02:16:3e:0a:00:01,bridge=vlan10,model=e1000

As an aside, I always advice people to not let Xen interfere with their
networking setup - if you use xend this means to have the second line
of network-bridge be ''exit 0''. That way you can just setup
your own
networking without the odd routine of network-bridge.

Basically the Xen scripts are scripts you can customise to your needs
in whatever way you want. Many people seem to be confused about this
but in the end it is all very easy to customise.

That being said, one feature that is currently missing is that I would
really like to be able to pass arguments to the scripts, for example
''vtag=10'' or ''vtag=trunk''. It seems
impossible, or at least I could not
find ways to do that without hacking other bits and pieces of Xen which
are not as easy to maintain when you upgrade Xen.

HTH,
Mark