Online TracePath

Tracepath6 is a traceroute alternative, a computer network tool used to determine (trace) the MTU value of each hop  along the path (route) taken by packets across an IP network.

The traceroute tool is available on practically all Unix-like operating systems. Variants with similar functionality are also available, such as tracepath on modern Linux installations and tracert on Microsoft Windows operating systems. Windows NT-based operating systems also provide pathping, which provides similar functionality.
Source: WikiPedia

An IPv6 version of this tool is available here!

This online tool performs a trace along the path your packets follows from this webserver to any destination on the internet and determine the MTU of each hop. Enter the domain name or IP number of the webserver you want to test e.g., www.yahoo.com. Be patient, this script may take utpo 60 seconds to return results, it does not print out the lines one by one, just returns the whole traceroute.