Sniffing activities are performed by malicious users / attackers in a Man-in-the-Middle (MitM) scenario where they want to grasp data flowing on the network. There are two types of sniffing attacks:

Passive sniffing refers to sniffing on a hubbed network, where all devices on the network are connected to a hub and since all the packets are sent to all the connected devices on a hub, the attacker simply needs to plug into that hub and listen to the conversations occurring over that hub. It is easy to sniff on a network that uses a hub, but it is very rare to find a hubbed network.

Active sniffing refers to sniffing on a switched network, where the devices are connected to a switch, and a switch, unlike a hub, does not broadcast all the packets to all the devices on the network. Hence, it is not as easy to perform sniffing on a network that uses a switch. Yet, it is not impossible to perform it on a switched network either.

In the current...