Install iftop with Homebrew

Project links

• Homepage

Commands and aliases

• iftop

Project history

The upstream ChangeLog records the first release as 0.1 on 2002-03-29. Early 2002 releases quickly added network-boundary analysis, cumulative totals, PPP support, Linux cooked sockets, port display, FreeBSD support, online help, service resolution controls, and bandwidth-in-bytes display.

By 2003 the tool had acquired autoconf/automake, better interface auto-selection, cumulative line totals, Solaris DLPI support, Mac OS X build fixes, config-file support, selectable averages, and command-line controls for port resolution.

Version 0.17 in 2006 added VLAN support and multiple portability fixes. Later 1.0 pre-release work added IPv6 support, text output mode, PFLOG support, many downstream portability fixes, and contributions routed through Debian, Fedora, Red Hat, and other users.

Adoption history

iftop spread widely through Unix and Linux package collections because it pairs libpcap packet capture with a top-like curses interface. The supplied metadata lists Alpine, Homebrew, Debian, Fedora, MacPorts, Nix, Arch, Ubuntu, and openSUSE-style package names.

The project page also maintained a mailing list, public archives, pre-release tarballs, and a git repository, which helped distribution maintainers track patches even when stable releases were infrequent. Homebrew's formula notes that distributions package a 1.0 pre-release because upstream movement slowed after the 2014 pre-release.

How it is used

Users usually run iftop on a selected interface to see bandwidth grouped by source and destination host pairs. The UI supports options and interactive toggles for hostnames, ports, sorting, totals, averages, filters, display scaling, and text output.

Because it uses libpcap, iftop often needs elevated privileges or packet-capture permissions. It is most useful during incident response, capacity checks, and quick diagnosis of unexpected traffic.

Why package nerds care

iftop is one of the canonical small admin packages: a memorable name, a single job, a curses UI, libpcap underneath, and years of downstream patches keeping it buildable across systems.

It also occupies the sweet spot between tcpdump and full network-monitoring suites. Package it once, run it over SSH, and get an immediate visual answer without setting up a daemon or dashboard.

Timeline

• 2002-03-29: 0.1 first release.
• 2002-10-22: 0.9 adds FreeBSD support, online help, service toggles, and bandwidth-in-bytes display.
• 2003-01-08: 0.11 adds autoconf/automake and improved interface auto-selection.
• 2003-11-10: 0.15 adds config-file support and display controls.
• 2006-02-12: 0.17 adds VLAN support and portability fixes.
• 2014-01-19: 1.0pre4 is the pre-release packaged by Homebrew and other distributions.

Related projects

• top is the direct interface analogy named by upstream.
• tcpdump, libpcap, pcap, ncurses, ntop, bmon, nload, iptraf-ng, and ifstat are adjacent command-line or terminal network-monitoring tools.

Sources

• https://code.blinkace.com/pdw/iftop
• https://code.blinkace.com/pdw/iftop/-/raw/master/ChangeLog
• https://formulae.brew.sh/formula/iftop
• https://pdw.ex-parrot.com/iftop/