install

Additional install commands

macOS

Homebrewverified · 100%

brew install lft

local Homebrew formula metadata

MacPortsverified · 94%

sudo port install lft

MacPorts ports tree · net/lft/Portfile · source: api.github.com

Linux

Debian aptverified · 92%

sudo apt install lft

Debian stable package indexes · lft · source: deb.debian.org

overview

Package summary

Layer Four Traceroute (LFT), an advanced traceroute tool

Project links

Commands and aliases

lft
whob

history

Project history and usage

LFT, Layer Four Traceroute, is a network diagnostic tool that extends traceroute-style path discovery with TCP, UDP, ICMP, AS lookup, netblock lookup, and firewall-aware heuristics. It is packaged together with WhoB, a whois-oriented companion tool for routed IP address context.

Project history

The official LFT page says LFT was first released publicly in 1998 under the name FFT. Its distinguishing idea was tracing with transport-layer probes, including TCP SYN or FIN probes to arbitrary services, instead of relying only on the classic UDP probe pattern associated with traditional traceroute.

The project has continued as an operational networking tool rather than a large hosted source-code community. The 3.95, 3.96, and 3.97 changelog entries document modernization work such as getaddrinfo/getnameinfo migration, asynchronous DNS through c-ares, Path MTU discovery, ncurses watch mode, and ECMP-stable tracing.

Adoption history

LFT's adoption is strongest among network engineers, reverse engineers, and operators who need route visibility across firewalls, ECMP paths, or protocol-specific forwarding behavior. Packaging in Homebrew, Debian, Ubuntu, and MacPorts makes it available in the same toolbox as traceroute, mtr, tcpdump, and whois.

How it is used

Users run `lft` to trace a path with TCP, UDP, ICMP, or RFC 1393 style probes, then use options for AS numbers, netblock names, verbose packet interpretation, or newer visual/statistical output. The bundled `whob` client provides quick origin-ASN and registry context for IP addresses.

Why package nerds care

LFT is a classic small networking package: specialized, privilege-sensitive, and valuable when the default platform traceroute does not model the path a service actually takes. Its continued packaging matters because it preserves a 1990s diagnostic idea that remains relevant on filtered and load-balanced networks.

Timeline

1998: The tool was released publicly under the name FFT, according to the official authors' note.
Version 2.5: Recent releases at that point included WhoB as a standalone client in the LFT binary directory.
2026-03: LFT 3.95 modernized resolver APIs and added asynchronous DNS.
2026: LFT 3.96 added active Path MTU Discovery and richer per-hop statistics.
2026-04: LFT 3.98 was announced with build-system fixes for Linux packaging and autoconf.

Related projects

LFT is related to traceroute, tcpdump/libpcap, whois clients, Prefix WhoIs, RIPE NCC and Team Cymru ASN lookups, mtr, and other operator-focused path diagnosis tools.

Sources

security posture

Risk level: green

narrow executable package without higher-risk signals.

Risk classifier

green risk · low confidence · appliance

Why

narrow executable package without higher-risk signals

Signals

metadata:no-higher-risk-signals

Install behavior

No Homebrew post-install hook is recorded in formula metadata.
Homebrew bottle metadata is available for 6 platform targets.

Recommended review

Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.

executables

Installed executables

Command	Kind	Exposure	Note
`lft`	cli	global executable
`whob`	cli	global executable

freshness

Version and freshness

These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.

page generated2026-07-08

manager version3.98

manager updated2026-04-29

local dataok

upstreamnot checked

latest detectednot detected

https://pwhois.org/lft/

infoRelease/tag comparison is only available for GitHub repositories.https://pwhois.org/lft/none confidence

install metadata

Package metadata

Package key	brew:lft
Version	3.98
Package manager	Homebrew
Package manager page	https://formulae.brew.sh/formula/lft
Homepage	https://pwhois.org/lft/
Upstream docs	https://pwhois.org/lft
License	VOSTROM
Source archive	https://pwhois.org/dl/index.who?file=lft-3.98.tar.gz
Last updated	2026-04-29T13:28:47Z
Pulse	updated
Uses from macOS	libpcap
Bottle	available (on arm64_linux, arm64_sequoia, arm64_sonoma, arm64_tahoe, sonoma, x86_64_linux)
Homebrew post-install	not defined
Service	none declared

registry facts

Source database details

Source Database	Homebrew formula API
Tap	homebrew/core
Full Name	lft
Version Scheme	0
Revision	0
Bottle Stable Root URL	https://ghcr.io/v2/homebrew/core
Deprecated	no
Disabled	no
Keg Only	no
URL Keys	stable

source database matches

Other package-manager records

Matches are pulled from external package-manager indexes and kept separate from local Automic Vault package links.

Debian apt95%

lft 3.91-2

layer-four traceroute

https://pwhois.org/lft/

sudo apt install lft

Section: net
Architecture: amd64
2 dependencies
normalized package name match
Matched by: Lft

Debian stable package indexes · deb.debian.org · Debian stable package indexes: lft from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz

Ubuntu apt95%

lft 3.91-1build2

layer-four traceroute

http://pwhois.org/lft/

sudo apt install lft

Section: universe/net
Architecture: amd64
2 dependencies
normalized package name match
Matched by: Lft

Ubuntu 24.04 LTS package indexes · archive.ubuntu.com · Ubuntu 24.04 LTS package indexes: lft from https://archive.ubuntu.com/ubuntu/dists/noble/universe/binary-amd64/Packages.gz

MacPorts95%

lft

sudo port install lft

normalized package name match
Matched by: Lft

MacPorts ports tree · api.github.com · MacPorts ports tree: net/lft/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1

package graph

Links come from deterministic package relationships, av.db category and tag curation, ecosystem matches, and package hub membership.

source trail

Generated from repository data

This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.

Combined YAML source

View the package source record on GitHub.

combined/lft.yml

Used sources

Geiger risk classifier
Nucleus package database
av.db category and tag curation
cross-ecosystem install command graph
curated package history
external package-manager database matches
package relationship graph
package version freshness
package-page enrichment

Install lft with Homebrew, apt, MacPorts