ICMP is a fundamental part of the Internet as it handles the control and error messages. ICMP's treatment by the network and in particular by different routers it may cross is therefore a key aspect driving troubleshooting and diagnosis processes. In this paper we present IBTrack, a tool that aims at characterizing how the network actually treats different ICMP messages from an user point of view. Specifically, we detail a classification algorithm to categorize router behaviors and we introduce its associated refining method which exploits multiple probing protocols. We illustrate the average Internet router behavior and path composition through results gathered from Planet-Lab nodes using a large CAIDA's snapshot of routed /24. We further show that our refining method improves the routers behavior characterization up to 10% for more than 1% of the total number of observed routers.
