On 07/25/2017 04:36 AM, ΒΆΒΆ wrote: > libvirt > version: 3.4.0 > architecture: x86_64 ubuntu16.04-server > hypervisor: kvm,qemu > > when install libvirt from ubuntu distribution deb install libvirt, a virtual bridge virbr0 will be create . But when I build libvirt from souce code, how can I create a virbr0. This may be due to the libvirt built from source doesn't have the correct prefix? I don't know how/whether ubuntu does it, but in many distros I've seen that they install default libvirt network (virsh net-dumpxml default) and also set it to autostart. Now, the configs for libvirt networks, domains, etc. is stored under /etc/libvirt. But if you build libvirt from sources and do not set --prefix, that libvirt will look under /usr/local/etc/libvirt. And since there is no network config, it doesn't start any. I should point out here that network should remain running even if libvirtd is shut down. The reason for that is to maintain connectivity for the domains. > If I want create another virtual bridge ,How can I create and start the virtual bridge. You need to define another network. http://libvirt.org/formatnetwork.html Michal _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users