Sniffing and scanning

These are terms used in networking that generally refer to the act of eavesdropping on traffic in a network. They enable both attackers and defenders to know exactly what is happening in a network. Sniffing tools are designed to capture the packets being transmitted over a network and to perform analysis on them, which is then presented in a human-readable format. In order to perform internal reconnaissance, packet analysis is more than essential. It gives attackers a lot of information about the network to a level where it can be compared to reading the logical layout of the network  on paper.

Some sniffing tools go to the extent of revealing confidential information, such as passwords from WEP-protected Wi-Fi networks. Other tools enable users to set them up to capture traffic over a long period of time on wired and wireless networks, after which the users can analyze at their own convenience. There are a number of sniffing tools available today that hackers commonly use.