https://blog.csdn.net/aienjoy/article/details/78994128
1.Down:
ifconfig virbr0 down
2.Delete:
brctl delbr virbr0
3.virbr0是由libvirtd服务创建，libvirtd在guest里没啥卵用，所以干掉它，不然下次启动又创建了:
systemctl disable libvirtd
原文：https://www.cnblogs.com/yaok430/p/13097463.html