Table of Contents Tcpkill GDB Tcpkill enables priviledged user to kill TCP connections, it uses the tcpdump expression. It’s part of the dsniff package. The default degree of brute force to use in killing a connection is 3, fast connections may require a higher number in order to land a RST in the moving receive window. tcpkill [-i interface] [-1...9] expression For example, to kill the established and also to prevent any connections from 192.