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<div>I believe this is so that security groups can be applied using iptables on those qbrXXX interfaces. At least that's how it works in our implementation under Havana.</div>
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<span style="font-weight:bold">From: </span>Dan Nanni <<a href="mailto:xmodulo@gmail.com">xmodulo@gmail.com</a>><br>
<span style="font-weight:bold">Date: </span>Tuesday, March 11, 2014 8:06 AM<br>
<span style="font-weight:bold">To: </span>"<a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a>" <<a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a>><br>
<span style="font-weight:bold">Subject: </span>[Openstack] Why is Neutron OVS topology the way it is?<br>
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<div dir="ltr">Hi,<br>
<br>
I was playing with OpenStack Neutron with OVS plugin. When I launch VMs, I noticed that there is a Linux bridge (qbrxxx) created for each VM, which is then connected to the OVS bridge (ovs-int). See the following.<br>
<br>
VM0 VM2<br>
| |<br>
qbrXXX qbrYYY (per-VM linux bridges)<br>
| |<br>
| | <br>
br-int (OVS bridge)<br>
|<br>
br-eth<br>
<br>
My question is, why couldn't VMs be directly connected to br-int (without qbr Linux bridges)? Why do we create additional Linux bridges between OVS bridge and VMs? What is the role of Linux bridges here?<br>
<br>
Thanks!<span class="HOEnZb"><font color="#888888"><br>
-Dan</font></span></div>
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