Hi All, Applied patch from below link in order to add ethernet network type support to LXC. https://www.redhat.com/archives/libvir-list/2016-January/msg00318.html Launching LXC based VM using openstack Icehouse release which uses libvirt in background fails with below error: LOG shows "*error : virNetDevVethCreate:196 : internal error: Failed to allocate free veth pair after 10 attempts*" and also gives* ret == -1 for* *virNetDevVethCreate which depicts that "**virNetDevVethCreate" failed.* But by defining XML file manually using *virsh* *utility* I am able to launch LXC based VM successfully with network type Ethernet. *Something went wrong while launching the same with openstack nova. * Please help as I am quite new to this virtualization world. Its urgent any help/pointers are welcome. Thanks Pradeep Kumar Regards Pradeep Kumar