Ettercap tool uses:

Ettercap - is a free and open source network security tool for man-in-the-middle attacks (MITM) on LAN. The security tool can be used to analyze computer network protocols within a security auditing context. Ettercap has four methods of functionality:
Security scanning by filtering IP-based packets, MAC-based: whereby packets are filtered based on MAC address, (this is useful for sniffing connections through a gateway). ARP-based scanning by using ARP poisoning to sniff on a switched LAN between two hosts (known as full-duplex). PublicARP-based functionality: Ettercap uses ARP poisoning to sniff on a switched LAN from a victim host to all other hosts (known as half-duplex).