Layer Four Traceroute – multi-protocol traceroute engine

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-filters (firewalls). More importantly, LFT implements numerous other features including AS number lookups through several reliable sources, loose source routing, netblock name lookups, et al.

LFT is the all-in-one traceroute tool because it can launch a variety of different probes using ICMP, UDP, and TCP protocols, or the RFC1393 trace method. For example, rather than only launching UDP probes in an attempt to elicit ICMP “TTL exceeded” from hosts in the path, LFT can send TCP SYN or FIN probes to target arbitrary services. Then, LFT listens for “TTL exceeded” messages, TCP RST (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. With LFT’s verbose output, much can be discovered about a target network.

This is free and open source software.

Website: pwhois.org/lft
Support:
Developer: VOSTROM Holdings, Inc
License: VOSTROM Public License for Open Source

LFT is written in C. Learn C with our recommended free books and free tutorials.

Alternatives to traceroute

Explore Linux
	Best Free and Open Source Software - A huge collection of recommended free and open source software covering every major category.
	In-depth Linux Software Reviews - Detailed assessments of Linux software covering features, usability and overall quality.
	The Big List of Active Linux Distros - An extensive collection of actively developed Linux distributions.
	Open Source Alternatives - Alternatives to software and services from Google, Microsoft, Apple, Adobe, IBM, Autodesk, Oracle and others.
	Essential Linux System Tools - Indispensable utilities for monitoring, maintaining and managing Linux systems.
	Linux Productivity Tools - Useful utilities for improving productivity and streamlining everyday tasks.
	Alternatives to Popular CLI Tools - Modern alternatives to familiar command-line utilities supplied with Linux systems.
	Awesome Free Linux Game Tools - Tools, utilities and companion software that improve gaming on Linux.
	Machine Learning on Linux - Machine learning and deep learning software, self-hosted applications and practical tools.
	Saving Money with Linux - Practical ways to reduce electricity consumption and lower computing costs with Linux.
	Linux Candy - Fun, entertaining and sometimes delightfully quirky software from the lighter side of Linux.