Sniffing is a technique used in ethical hacking to keep track of all data packets passing over a network. Network/System Administrators are in charge of sniffers, which are generally used to monitor and debug network traffic. Sniffers can be software or hardware that is installed in the system.
Sniffers, on the other hand, maybe used by attackers to obtain access to data packets containing sensitive information such as account information, passwords, and so on. A malevolent hacker might use packet sniffers on a network to enter and access all of the network traffic.
Sniffing may be divided into two categories:
Active sniffing: Active sniffing is the term used to describe sniffing in point-to-point network equipment known as a switch. The switch is in charge of controlling the data flow between its ports. This is accomplished by actively monitoring the MAC address on each port, allowing data to be sent only to the designated recipient. Sniffers must inject traffic into the LAN to enable sniffing of communication between targets.
Passive sniffing: When smelling is done through the hub, it is called passive sniffing. All computers in the unbridged network or non-switched segment are unaware of the traffic that passes across it. Sniffers operate at the data connection layer of a network. This is known as passive sniffing since the sniffers set up by the attackers passively wait for the data to be transmitted before capturing it.