How to install tcpkill and kill hosts

>cd usr/ports/security/dsniff
>make config

uncheck the X11 support.

>make install clean

now it's installed and ready to use.
To kill a network just type:

>tcpkill -9 net 192.168.1

like this for a individual hosts:

>tcpkill -9 net 192.168.1.13

or you can name ports

>tcpkill -9 port 8888 and port 6699