# Install lft with Homebrew, apt, MacPorts Layer Four Traceroute (LFT), an advanced traceroute tool. Version 3.98 via Homebrew; verified 2026-04-29. ## Install ```sh sudo av install brew:lft ``` Additional install commands: ### macOS - Homebrew (100%): ```sh brew install lft ``` Evidence: local Homebrew formula metadata - MacPorts (94%): ```sh sudo port install lft ``` Evidence: MacPorts ports tree: net/lft/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1 ### Linux - Debian apt (92%): ```sh sudo apt install lft ``` Evidence: Debian stable package indexes: lft from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz ## Package facts - **Package key:** brew:lft - **Package manager:** Homebrew - **Package manager page:** - **Version:** 3.98 - **Source summary:** Layer Four Traceroute (LFT), an advanced traceroute tool - **Homepage:** - **Upstream docs:** - **License:** VOSTROM - **Source archive:** - **Last updated:** 2026-04-29T13:28:47Z - **Generated:** 2026-07-08T18:08:21+00:00 ## Executables - lft (cli) - whob (cli) - lft (alias) - whob (alias) ## Uses from macOS - libpcap ## Install behavior - Post-install hook: not defined - Bottle: available on arm64_linux, arm64_sequoia, arm64_sonoma, arm64_tahoe, sonoma, x86_64_linux ## Freshness - Page generated: 2026-07-08 - Package-manager version: 3.98 - Package-manager updated: 2026-04-29 - Local data: ok - Upstream repository: https://pwhois.org/lft/ - info: Release/tag comparison is only available for GitHub repositories. ## 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 Notes narrow executable package without higher-risk signals. - **Geiger risk:** green / low - narrow executable package without higher-risk signals ## Source Database Details - **Source Database:** Homebrew formula API - **Tap:** homebrew/core - **Full Name:** lft - **Version Scheme:** 0 - **Revision:** 0 - **Bottle Stable Root URL:** - **Deprecated:** no - **Disabled:** no - **Keg Only:** no - **URL Keys:** stable ## Other Package-Manager Records - Debian apt - lft - 3.91-2: normalized package name match | Debian stable package indexes: lft from https://deb.debian.org/debian/dists/stable/main/binary-amd64/Packages.xz | layer-four traceroute | https://pwhois.org/lft/ - Ubuntu apt - lft - 3.91-1build2: normalized package name match | Ubuntu 24.04 LTS package indexes: lft from https://archive.ubuntu.com/ubuntu/dists/noble/universe/binary-amd64/Packages.gz | layer-four traceroute | http://pwhois.org/lft/ - MacPorts - lft: normalized package name match | MacPorts ports tree: net/lft/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1 ## Related links - [Terminal utility packages](https://www.automicvault.com/pkg/terminal-utilities/) - Matched terminal and command-line workflow metadata. - [Networking and protocol packages](https://www.automicvault.com/pkg/networking-protocol-tools/) - Matched network, protocol, or remote-service metadata. - [Homebrew utility packages](https://www.automicvault.com/pkg/brew-utility-packages/) - Matched Homebrew package provider. - [trippy](https://www.automicvault.com/pkg/brew/trippy/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking, traceroute. - [tcptraceroute](https://www.automicvault.com/pkg/brew/tcptraceroute/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking, tcp. - [fastrace](https://www.automicvault.com/pkg/brew/fastrace/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking, traceroute. - [mtr](https://www.automicvault.com/pkg/brew/mtr/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking, traceroute. - [nexttrace](https://www.automicvault.com/pkg/brew/nexttrace/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking, traceroute. - [tracebox](https://www.automicvault.com/pkg/brew/tracebox/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking, traceroute. - [cloudflare-speed-cli](https://www.automicvault.com/pkg/brew/cloudflare-speed-cli/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking. - [fping](https://www.automicvault.com/pkg/brew/fping/) - Shares av.db curated category or tags: cli, diagnostics, network-diagnostics, networking. ## Combined YAML source View the package source record on GitHub. [combined/lft.yml](https://github.com/automic-vault/db/blob/main/combined/lft.yml) ## Sources - Nucleus package database - Geiger risk classifier - package-page enrichment - curated package history - package version freshness - av.db category and tag curation - package relationship graph - external package-manager database matches - cross-ecosystem install command graph