A full-featured suite of packet/host analysis tools for securing switched networks.
Ettercap is a traffic and host analysis tool for switched networks. Features include automation of man-in-the-middle techniques for grabbing packets on a switched network, bridged sniffing, ARP poisoning, DHCP spoofing and port stealing. Ettercap's traffic analysis tools, content filtering features and live connection monitoring provide an environment for active and passive dissection of many protocols (including ciphered ones).
Ettercap has several built-in user interfaces: plain text, ncurses and GTK for X11.
Ettercap does not provide pre-built binaries. It must be compiled from source or installed using a package manager (MacPorts or Homebrew, for example).