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how does kolla configure br-ex?

asked 2017-12-06 17:41:18 -0600

jcorkey gravatar image

I deployed using kolla/kolla-ansible 5.0.0 on one compute node and one control node.

How does kolla configure the br-ex bridge??? After deploying, I can see that there are three bridges br-int, br-tun, and br-ex by running ovs-vsctl show

But where is the ifcfg-br-ex files?? Do I need to add the ifcfg-br-ex? I am getting confused with things since openstack services are running within containers,. I am having uses with pinging the floating IP's and router in openstack and I think it is an issue with the br-ex.

I have added all the correct security groups so I know thats NOT the problem.

So I am trying to understand how much I am responsible for configuring the br-ex or does kolla do all that for me?

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check /etc/kolla/neutron-openvswitch-agent/ .in this file there is ovs tag which defines bridge mapping. each neutron service has ml2 file in is configured by kolla itself in network node

akarki gravatar imageakarki ( 2017-12-06 23:01:16 -0600 )edit

Ok thanks. I’m still a little confused though. I see br-int, br-tun, br-ex when I run the ovs-vsctl show in the openvswitchd container and it all looks correct but when I run nmcli d or ip a br-int, br-tun, br-ex say they are unmanaged. Like in the output in the comment below. Why is that?

jcorkey gravatar imagejcorkey ( 2017-12-06 23:16:58 -0600 )edit

br-ex openvswitch unmanaged br-int openvswitch unmanaged br-tun openvswitch unmanaged ovs-system openvswitch unmanaged

jcorkey gravatar imagejcorkey ( 2017-12-06 23:27:03 -0600 )edit

br-ex br-int and br-tun are supposed to have no ip address and are in down state after deployement.

akarki gravatar imageakarki ( 2017-12-06 23:32:33 -0600 )edit

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answered 2017-12-07 08:51:06 -0600


  • Kolla reads neutron_external_interface variable.
  • The create a bridge br-ex in OVS (not the host/hypervisor)
  • Lastly attach the interface into the bridge.,#L21

The host does not need configuration file for the bridge nor the interface manually attached as OVSport in the bridge. Only need a interface UP with no IP address associated to it. When a network is created, the traffic will flow through:

bridge (br-ex) -> physical interface (eth2) -> external router/switch outside openstack (neutron gateway)


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Asked: 2017-12-06 17:41:18 -0600

Seen: 36 times

Last updated: Dec 07