https://www.juniper.net/documentation/en_US/vmx15.1f6/topics/task/operational/vmx-managing.html
Note: If you cannot deploy vMX after upgrading libvirt, bring down the virbr0 bridge with the ifconfig virbr0 down command and delete the bridge with the brctl delbr virbr0 command. |
[root@hp8300 vmx]# ifconfig virbr0 down
[root@hp8300 vmx]# brctl delbr virbr0
[root@hp8300 vmx]# virsh net-start default
Network default started
[root@hp8300 vmx]# virsh net-dumpxml default
...