tcpkill
Terminate TCP connections with resets
TLDR
Kill connections by interface, host, and port
SYNOPSIS
tcpkill [OPTIONS] EXPRESSION
DESCRIPTION
tcpkill terminates in-progress TCP connections by injecting TCP RST (reset) packets. It monitors traffic matching the specified filter expression and sends forged reset packets to both endpoints.
The filter expression uses libpcap syntax, allowing filtering by host, port, network, or any combination.
PARAMETERS
-i INTERFACE
Network interface to use-1 to -9
Aggressiveness level (default: 3)
CAVEATS
Requires root privileges. Part of the dsniff package. Only works on unencrypted connections visible on the network. May require multiple attempts for active connections. Use responsibly - unauthorized use may be illegal.
HISTORY
tcpkill is part of the dsniff suite created by Dug Song for network auditing. It's used for security testing and emergency connection termination.