Detection
As promiscuous mode can be used in a malicious way to sniff on a network, one might be interested in detecting network devices that are in promiscuous mode. In promiscuous mode, some software might send responses to frames even though they were addressed to another machine. However, experienced sniffers can prevent this (e.g., using carefully designed firewall settings).
An example is sending a ping (ICMP echo request) with the wrong MAC address but the right IP address. If an adapter is operating in normal mode, it will drop this frame, and the IP stack never sees or responds to it. If the adapter is in promiscuous mode, the frame will be passed on, and the IP stack on the machine (to which a MAC address has no meaning) will respond as it would to any other ping. The sniffer can prevent this by configuring his firewall to block ICMP traffic.
Read more about this topic: Promiscuous Mode