Using TCPKILL to send RST to cut off TCP connectivities

In Kali Linux, the tcpkill application is located at /usr/sbin/tcpkill.

Usage:
/usr/sbin/tcpkill -i NETWORK_INTERFACE -DEGREE TCPDUMP_FILTER_EXPRESSION
Example:
/usr/sbin/tcpkill -i eth0 -9 host 192.168.0.2 and host 192.168.3.10

NETWORK_INTERFACE is the network interface going to send out RST segments.
DEGREE is a number representing the rate of sending RST segments. The range of the number is from 1 to 9. The higher number, the faster rate. The filter expression of TCPDUMP can refer to the manual of TCPDUMP.