Information, Computer and Network Security Terms Glossary and
Sniffer, a product originally created and trade-marked by Network General, is basically a program and/or device that monitors data traveling over a network. Sniffers can be used both for legitimate network management functions and for stealing information off a network. Network operations and maintenance personnel use a Sniffer to monitor network traffic, analyze packets, watch network resource utilization, conduct forensic analysis of network security breaches and troubleshoot network problems. Unauthorized Sniffers can be extremely dangerous to a network's security because they are virtually impossible to detect and can be inserted almost anywhere. This makes them a favorite weapon in the hacker's arsenal.