An explanation of sniffers and a look at how to detect them.
Sniffers are basically data interception programs.
They work because the Ethernet was built around a principle of sharing. Most networks use what is known as broadcast technology, meaning that every message transmitted by one computer on a network can be read by any other computer on that network. In practice, all the other computers, except the one for which the message is meant, will ignore that message. However, computers can be made to accept messages, even if they are not meant for them, by means of a sniffer. How a Sniffer Works Suppose the machine Venus wants to talk to the machine Cupid.