Promiscuous mode eliminates any reception filtering that the virtual network adapter would perform so that the guest operating system receives all traffic observed on the wire. By default, the virtual network adapter cannot operate in promiscuous mode.

Although promiscuous mode can be useful for tracking network activity, it is an insecure mode of operation, because any adapter in promiscuous mode has access to the packets regardless of whether some of the packets are received only by a particular network adapter. This means that an administrator or root user within a virtual machine can potentially view traffic destined for other guest or host operating systems.

Note

In some situations, you might have a legitimate reason to configure a virtual switch to operate in promiscuous modeā€”for example, if you are running network intrusion detection software or a packet sniffer.