Network sniffing is the use of a software tool, called a network sniffer, to monitor or sniff data flowing over computer network links in real time. This software tool is either a standalone software program or a hardware device with the appropriate software or firmware.
What is a Network Sniffer and How to Protect Yourself from It (Part 1)
Network sniffers create snapshot copies of the data flowing over a network without rerouting or modifying it. Some sniffers work only with TCP/IP packets, but more advanced tools work with many other network protocols and at lower levels, including Ethernet frames.
Years ago, sniffers were tools used exclusively by professional network engineers. Today, however, with software available for free on the web, they are also popular with Internet hackers and people who are curious about networks.
There are a wide range of applications for packet sniffers. Most packet sniffers can be used incorrectly by one person and legitimately by another.
