This article describes how a Linux IPTables based firewall/router can be used to send the right combination of TCP/IP packets to both ends of a connection to cause them to abort the conversation. It describes the steps required to perform this task, and introduces a new open-source utility called "cutter" that automates the process.
June 19, 2003
TCP/IP Connection cutting for Linux Firewalls
Author: Benjamin D. Thomas
Chris Lowth writes "Network security administrators sometimes need to be able to abort TCP/IP connections routed over their firewalls on demand. This would allow them to terminate connections such as SSH tunnels or VPNs left in place by employees over night, abort hacker attacks when they are detected, stop high bandwidth consuming downloads - etc. There are many potential applications.