Package tcptraceroute: Information
Source package: tcptraceroute
Version: 1.5-alt5
Build time: Apr 12, 2007, 11:54 PM
Category: Monitoring
Report package bugHome page: http://michael.toren.net/code/tcptraceroute
License: GPL
Summary: A traceroute implementation using TCP packets
Description:
tcptraceroute is a traceroute implementation using TCP packets. The more traditional traceroute(8) sends out either UDP or ICMP ECHO packets with a TTL of one, and increments the TTL until the destination has been reached. By printing the gateways that generate ICMP time exceeded messages along the way, it is able to determine the path packets are taking to reach the destination. The problem is that with the widespread use of firewalls on the modern Internet, many of the packets that traceroute(8) sends out end up being filtered, making it impossible to completely trace the path to the destination. However, in many cases, these firewalls will permit inbound TCP packets to specific ports that hosts sitting behind the firewall are listening for connections on. By sending out TCP SYN packets instead of UDP or ICMP ECHO packets, tcptraceroute is able to bypass the most common firewall filters. It is worth noting that tcptraceroute never completely establishes a TCP connection with the destination host. If the host is not listening for incoming connections, it will respond with an RST indicating that the port is closed. If the host instead responds with a SYN|ACK, the port is known to be open, and an RST is sent by the kernel tcptraceroute is running on to tear down the connection without completing three-way handshake. This is the same half-open scanning technique that nmap(1) uses when passed the -sS flag.
Maintainer: Dmitry V. Levin
Last changed
April 12, 2007 Dmitry V. Levin 1.5-alt5
- Added summary to control script.
May 25, 2006 Dmitry V. Levin 1.5-alt4
- Deal with compilation warnings generated by new gcc compiler.
March 29, 2006 Dmitry V. Levin 1.5-alt3
- Updated tcptraceroute-1.5beta7. - Updated patches.