不知为何安装的虚拟机在桥连时出现这个问题：
"The network bridge on device VMnet0 is not running.The virtual machine will not
be able to communicate with the host or with other machines on your network.
Virtual device Ethernet0 will start disconnected."
搜了下要安装这个，那个。很麻烦。其实只要虚拟机edit下，虚拟机网络设置中，复位一下就行。同时复位前要关闭一下操作系统。