LFT (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 TCP, UDP, or ICMP-based traces, AS number lookups through several reliable sources, loose source routing, netblock name lookups, and more. LFT also distinguishes between layer-4 protocols, which make its statistics slightly more realistic, and gives a savvy user the ability to trace protocol routes, not just layer-3 hops.
| Tags | Systems Administration Networking Monitoring Firewalls |
|---|---|
| Licenses | Freeware Open Software |
| Operating Systems | POSIX Linux BSD Mac OS X Solaris |
| Implementation | C |
Recent releases


Release Notes: Support was added for several common network encapsulations, including popular Linux cooked capture and PPP for compatibility with mobile broadband cards.


Release Notes: This release improves compatibility on more platforms and versions such as Solaris and Mac OS X or Darwin.


Release Notes: Many minor improvements, including a significant security fix on Mac OS X.


Release Notes: WhoB default behavior was changed due to popular demand. New configure options were added to perform universal builds and to force gettimeofday calls instead of relying on possibly low-precision packet header times on some platforms. The build process was improved on NetBSD and Darwin/Mac OS X.


Release Notes: Improved TCP and UDP traces. A new ICMP tracing method, including RFC1393 capabilities. A new TCP Basic trace method that works in NAT'd environments. Library improvements to call LFT functions from within your programs. Now builds on Windows. Many bugfixes.
Recent comments
02 Nov 2002 23:06
Re: Building on FreeBSD
These items (below) are now fixed and applied to all
platforms in release 2.0.
> Software does not buiild out of the box
> on FreeBSD 4.6 at least.
>
> Change to get it to work is trivial:
>
> In fft.c:
> #ifndef BSD
> #include "fft_queue.h"
> #endif
>
> Just comment out/remove the first and
> last lines.
29 Sep 2002 11:11
Building on FreeBSD
There's no easy contact info on the site for contacting anyone regarding FFT.
Software does not buiild out of the box on FreeBSD 4.6 at least.
Change to get it to work is trivial:
In fft.c:
#ifndef BSD
#include "fft_queue.h"
#endif
Just comment out/remove the first and last lines.
29 Jun 2002 00:23
Re: tcptraceroute
> how does this differ from tcptraceroute
fft has been around since 1997-8, several years before tcptraceroute was conceived. (see google pages from MIT) But tcptraceroute definitely looks promising :-)
28 Jun 2002 10:35
tcptraceroute
how does this differ from tcptraceroute
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