A network sniffer is a program or dedicated hardware tool that intercepts and stores information about data packets traveling through the network. Sniffers may be an essential part of monitoring company communications and routing information or an intrusive tool that allows hackers and outsiders to view data traveling across a network. Sniffers do not alter or damage packets.
Network sniffers are often used legitimately as part of managed networks to ensure adequate flow of information between data centers and check the validity of traffic as it passes. Early sniffers worked primarily on the TCP/IP protocol, but more advanced network sniffers can work on Ethernet frames and similar setups. Sniffers help experts solve a variety of common problems related data transmission speeds or loss.
Amateurs seeking to learn more about the ins and outs of networking may choose to use a dedicated hardware or software network sniffer on their home systems to view transmission information and packets across their private channels. Hackers also use these programs to learn more about the activities of their targets and even emulate commands or inputs. Anti-sniffer technology that verifies the security of systems and works against these attempts is available for network owners who wish to prevent this type of intrusion in their personal or business networks.