Arp spoofing works even over switched ethernet. With it, you can convince other machines that yours is their gateway, and then you can not only see, but modify

Arp spoofing works even over switched ethernet. With it, you can convince other machines that yours is their gateway, and then you can not only see, but modify all their network traffic. https://en.wikipedia.org/wiki/ARP_spoofing https://en.wikipedia.org/wiki/ARP_spoofing