Packet sniffing: a brief introduction

Packet sniffing is a method of tapping each packet as it flows across the network; i.e., it is a technique in which a user sniffs data belonging to other users of the network. Packet sniffers can operate as an administrative tool or for malicious purposes. It depends on the user´s intent. Network administrators use them for monitoring and validating network traffic. Packet sniffers are basically applications. They are programs used to read packets that travel across the network layer of the Transmission Control Protocol/Internet Protocol (TCP/IP) layer. (Basically, the packets are retrieved from the network layer and the data is interpreted.) Packet sniffers are utilities that can be efficiently used for network administration. At the same time, it can also be used for nefarious activities. However, a user can employ a number of techniques to detect sniffers on the network and protect the data from sniffers. The technique behind packet sniffing on shared bus broadcast LANs is explained.