[ovs-discuss] [LXC support] veth interface added before VM existence

[Pierre-François Bonnefoi]

Hello,

I'm trying to figure the right way to proceed with the less hassle for my students :
* I use openvswitch to interconnect multiple LXC based VMs ;
* I don't use brcompat modul as it is deprecated ;
* I use this method :
1- I create the bridge with openvswitch;
2 - I add my veth interface by its name VETH_INTERNAL_A (before the associated LXC container creating it);
3 - I create my container with the same veth interface name VETH_INTERNAL_A (a simple one with lxc-execute for just a shell);
4 - the veth interface VETH_INTERNAL_A is created and the connectivity into the bridge could be tested : the bridge learn the mac address associated to the container;
5 - I configure port mirroring to sniff traffic from the container : it works.
6 -  the interface is present in the openvswitch bridge associated to the "up" status;

Now, the part the tricky part :
6 - I quit the container and the interface  VETH_INTERNAL_A is removed (not appearing anymore with the command "ip link");
7 - the interface is present in the openvswitch bridge associated to the "down" status;
8 - I relaunch the container : the interface is recreated with the same name and the associated status in openvswitch bridge is "up";
9- BUT the bridge doesn't LEARN THE MAC of the container !
10 - I try to configure port mirroring : Hop the bridge resume working and learning !

So, my questions are :
- What is wrong with the behavior of the openvswitch bridge ?
- Does adding a non existing interface by its name into an openvswitch bridge is wrong ?
- So why does it works the first time ? and not the second after container relaunch ?
- Does exist a better and RIGHT way to do it ?

Thank you for your support,
regards,
Pierre-François.

-- 
Bonnefoi Pierre-Francois                |    E-mail : bonnefoi at unilim.fr http://libpfb.so/
Universite de Limoges, Laboratoire XLIM |       Tel : 06 28 18 03 38
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