LFT for Mac

From MainNerve:

LFT, short for Layer Four Traceroute, is a sort of 'traceroute' that often works much faster (than the commonly-used Van Jacobson method) and goes through many configurations of packet-filter based firewalls. More importantly, LFT implements numerous other features including AS number lookups, loose source routing, netblock name lookups, et al.

What makes LFT unique? Rather than launching UDP probes in an attempt to elicit ICMP TIME_EXCEEDEDs from hosts in the path, LFT accomplishes substantively the same effect using TCP SYN or FIN probes. Then, LFT listens for TIME_EXCEEDED messages, TCP RESET, and various other interesting heuristics from firewalls or other gateways in the path. LFT also distinguishes between TCP-based protocols (source and destination), which make its statistics slightly more realistic, and gives a savvy user the ability to trace protocol routes, not just layer-3 (IP) hops.