lsnet 0.8.0

See what's on your local network: fast, zero-config device discovery and identification
lsnet-0.8.0 is not a library.

lsnet

See what's on your local network. lsnet finds every device on your LAN and tells you what each one is (an Apple TV, a printer, a smart plug, a NAS) in about two seconds, with no configuration and no flags to learn.

$ lsnet
 lsnet  14 devices on 192.168.1.0/24 (en0) in 2.0s
┌ Devices (14) ─────────────────────────────────────────────┐┌ Living Room ──────────────────────────────────┐
│  IP              NAME               TYPE                  ││ TV / streamer · Apple TV 4K (3rd gen)         │
│  192.168.1.1     Home Router        Router (gateway)      ││                                               │
│  192.168.1.8     Brother HL-L2350DW Printer               ││ IP             192.168.1.52                   │
│  192.168.1.14    diskstation        NAS                   ││ Hostname       living-room                    │
│› 192.168.1.52    Living Room        TV / streamer         ││ Open ports     7000 AirPlay · 62078 iOS sync  │
│  192.168.1.60    Kitchen            Speaker               ││                                               │
│  192.168.1.71    Office speaker     Speaker               ││ Bonjour (mDNS)                                │
│  192.168.1.88    kp115              Smart plug            ││ Name           Living-Room.local              │
│  192.168.1.90    blink-mini         Camera                ││ airplay        Living Room                    │
│  192.168.1.112   alex-phone         Phone / tablet        ││                model = AppleTV14,1            │
│  192.168.1.130   raspberrypi.local  Computer              ││ raop           6C4A85D1E0F2@Living Room       │
│  192.168.1.150   pihole             DNS server            ││                am = AppleTV14,1               │
│  192.168.1.196   Alex's MacBook Pro Computer (this device)││ companion-link Living Room                    │
│  192.168.1.201   ·                  Computer              ││                rpmd = AppleTV14,1             │
│  192.168.1.203   ·                                        ││                                               │
│                                                           ││                                               │
└───────────────────────────────────────────────────────────┘└───────────────────────────────────────────────┘
 ↑↓ move  tab services  ⏎ copy IP  c copy details  / filter  r rescan  ? help  q quit

It's meant to answer the question "what is that?" faster and more simply than nmap. It isn't a port scanner or a security tool.

Features

  • Zero config. It detects your interface, subnet and gateway on its own.
  • Fast. Every discovery method runs concurrently, and a /24 takes about 2 seconds.
  • Identifies devices, not just addresses. It combines what devices announce about themselves (Bonjour, UPnP, Windows and Samba NetBIOS names), their naming conventions, web UI banners, open ports (including homelab staples like Proxmox, Plex and Home Assistant) and MAC vendors into a type and a model.
  • Works without root. On Linux and Windows you even get MAC addresses and vendors without it. On macOS, some come through anyway: Windows and Samba hosts report theirs over NetBIOS, and AirPlay speakers and Linux machines put theirs in their Bonjour names.
  • macOS, Linux and Windows.
  • Browse or print. In a terminal, lsnet opens a browser with everything known about each device. When piped, or with -l, it prints a table.
  • Find your servers. Tab in the browser, or -s, lists every service on the network (web UIs, SSH, file shares, databases, Plex, Proxmox, Home Assistant) with the address to reach it.
  • Scriptable. --json outputs every piece of evidence behind each identification.

Install

lsnet runs on macOS, Linux (x86_64 and 64-bit ARM, including 64-bit Raspberry Pi OS) and Windows 10 or later (x86_64).

With Homebrew, on macOS and Linux:

brew install sanford/tap/lsnet

On Windows, with Scoop:

scoop bucket add sanford https://github.com/sanford/scoop-bucket
scoop install sanford/lsnet

Or download lsnet-windows-x64.zip from the latest release, unzip it, and put lsnet.exe in a folder on your PATH. It needs nothing else installed. Or, from PowerShell:

$dir = "$env:LOCALAPPDATA\Programs\lsnet"
Invoke-WebRequest https://github.com/sanford/lsnet/releases/latest/download/lsnet-windows-x64.zip -OutFile "$env:TEMP\lsnet.zip"
Expand-Archive "$env:TEMP\lsnet.zip" $dir -Force
[Environment]::SetEnvironmentVariable('Path', "$([Environment]::GetEnvironmentVariable('Path', 'User'));$dir", 'User')

Then open a new terminal and run lsnet.

With Cargo, if you have a Rust toolchain, from crates.io (on Windows, see below):

cargo install lsnet

Or build from source:

git clone https://github.com/sanford/lsnet
cd lsnet
cargo build --release
./target/release/lsnet

While hacking on it, ./run.sh [ARGS] (or .\run.ps1 [ARGS] on Windows) builds, installs to ~/.local/bin, and runs in one step.

Installing Rust on Windows

Rust on Windows uses Microsoft's C++ linker, so it needs the Visual Studio Build Tools as well as Rust itself. Both install with winget, from PowerShell:

winget install Microsoft.VisualStudio.2022.BuildTools --override "--wait --passive --add Microsoft.VisualStudio.Workload.VCTools --includeRecommended"
winget install Rustlang.Rustup

The first command installs the "Desktop development with C++" workload, about 2 GB, and takes a while. If the Build Tools are already installed, it fails with "already installed", which is fine. Add the workload from the Visual Studio Installer instead if it's missing.

Then open a new terminal, so cargo is on your PATH, and check that it works:

cargo --version
cargo install lsnet
lsnet

lsnet needs no administrator rights on Windows. If the scan finds devices but no names or models, check that Windows has the network set to Private rather than Public (see Firewalls).

Usage

lsnet [OPTIONS]

  -i, --interface <NAME>  Network interface to scan (default: the one your internet traffic uses)
  -n, --net <CIDR>        Network to scan, up to a /16 (default: see "Which network it scans")
  -l, --list              Print a table instead of opening the device browser
  -v, --verbose           Print a table that also shows hostnames, open ports and advertised services
  -s, --services          List the services running on the network instead of devices
      --json              Print results as JSON
  -t, --timeout <MS>      How long to wait for devices to answer [default: 1200]
      --no-dns            Skip reverse DNS lookups

Some examples:

lsnet                  # browse the devices on your network
lsnet -l               # just print the list
sudo lsnet             # also show MAC addresses and vendors
lsnet -v               # show the evidence: hostnames, ports, services
lsnet -s -l            # print every service and its address
lsnet -t 3000          # wait longer for sleepy Wi-Fi devices
lsnet --net 10.0.0.0/16 # scan all of a large network, not just your /24
lsnet --json | jq '.[] | select(.type == "Printer")'

The device browser

Run in a terminal, lsnet opens the browser shown at the top. Devices are listed on the left, and everything lsnet learned about the selected one is on the right: open ports, Bonjour services with their TXT records, UPnP details and the web page banner. Press ? to see every key:

Key Action
↑ ↓ or j k Move through the list
g G or Home End Jump to the first or last row
Tab Switch between devices and services
Enter or y Copy the selected IP address (or, for a service, its address and port) to the clipboard
c Copy all the details to the clipboard as plain text
PgUp PgDn or Ctrl-u Ctrl-d Scroll the details by half a page
J K Scroll the details by one line
/ Filter by IP, name, type, model, vendor, MAC or hostname, and in the services view by port or service. Enter keeps the filter, Esc clears it
r Scan again, keeping your place
Esc Clear the filter, or quit if there isn't one
h or ? Show all the keys
q or Ctrl-c Quit

Emacs keys work too: Ctrl-n Ctrl-p move down and up, Ctrl-v Alt-v scroll the details like PgDn PgUp, Alt-< Alt-> jump to the first or last row, and Ctrl-g clears the filter (it never quits).

Selecting text with the mouse picks up both panes, so use c to copy the details instead. It copies every line, including any scrolled out of view, without wrapping. In narrow terminals the details appear below the list instead of beside it. Copying uses pbcopy on macOS, wl-copy, xclip or xsel on Linux, and the clipboard directly on Windows. Without any of those, lsnet asks the terminal to do the copy, which also works over SSH in most modern terminals.

The services view

Press Tab in the browser, or start it with lsnet -s, to list services instead of devices: one row per server, sorted by address, with the device's details beside it as usual.

$ lsnet -s
 lsnet  14 devices on 192.168.1.0/24 (en0) in 2.0s
┌ Services (21) ───────────────────────────────────────┐┌ diskstation ────────────────────────────────────────┐
│  ADDRESS            SERVICE        HOST              ││ NAS · Synology DS920+                               │
│  192.168.1.1:53     DNS            Home Router       ││                                                     │
│  192.168.1.1:80     HTTP           Home Router       ││ IP            192.168.1.14                          │
│  192.168.1.1:443    HTTPS          Home Router       ││ Hostname      diskstation                           │
│  192.168.1.8:80     HTTP           Brother HL-L2350DW││ Open ports    22 SSH · 80 HTTP · 139 NetBIOS · 443  │
│  192.168.1.8:443    HTTPS          Brother HL-L2350DW││               HTTPS · 445 SMB · 5001 HTTPS · 32400  │
│  192.168.1.8:9100   printing       Brother HL-L2350DW││               Plex                                  │
│  192.168.1.14:22    SSH            diskstation       ││                                                     │
│  192.168.1.14:80    HTTP           diskstation       ││ Bonjour (mDNS)                                      │
│  192.168.1.14:139   NetBIOS        diskstation       ││ Name          diskstation.local                     │
│  192.168.1.14:443   HTTPS          diskstation       ││ smb           diskstation                           │
│  192.168.1.14:445   SMB            diskstation       ││                                                     │
│  192.168.1.14:5001  HTTPS          diskstation       ││ Web (port 80)                                       │
│› 192.168.1.14:32400 Plex           diskstation       ││ Title         diskstation - Synology DiskStation    │
│  192.168.1.88:80    HTTP           kp115             ││ Server        nginx                                 │
│  192.168.1.130:22   SSH            raspberrypi.local ││                                                     │
│  192.168.1.130:1883 MQTT           raspberrypi.local ││                                                     │
│  192.168.1.130:8123 Home Assistant raspberrypi.local ││                                                     │
│  192.168.1.150:22   SSH            pihole            ││                                                     │
│  192.168.1.150:53   DNS            pihole            ││                                                     │
│  192.168.1.150:80   HTTP           pihole            ││                                                     │
│  192.168.1.201:3389 RDP            ·                 ││                                                     │
└──────────────────────────────────────────────────────┘└─────────────────────────────────────────────────────┘
 ↑↓ move  tab devices  ⏎ copy address  c copy details  / filter  r rescan  ? help  q quit

It lists the open ports lsnet found (all but AirPlay, Cast and iPhone sync, which are how devices talk to phones rather than servers) plus the web, SSH, file-sharing, VNC and similar services devices advertise over Bonjour, on whatever port they use. This machine's own services aren't listed, since lsnet doesn't probe it. lsnet -s -l prints the same list as a table (see Text output), and lsnet -s --json gives ip, port, service and host for each.

Text output

When you quit the browser, lsnet prints the results as a table, so they stay in your terminal after it closes. To skip the browser and print the table straight away, use -l. lsnet also skips the browser when its output is piped or redirected, and with -v or --json.

$ lsnet -l
 IP             NAME                TYPE                    MODEL
 192.168.1.1    Home Router         Router (gateway)        Netgear RAX50
 192.168.1.8    Brother HL-L2350DW  Printer                 Brother HL-L2350DW series
 192.168.1.14   diskstation         NAS                     Synology DS920+
 192.168.1.52   Living Room         TV / streamer           Apple TV 4K (3rd gen)
 192.168.1.60   Kitchen             Speaker                 HomePod mini
 192.168.1.71   Office speaker      Speaker                 Google Nest Mini
 192.168.1.88   kp115               Smart plug              TP-Link Kasa KP115
 192.168.1.90   blink-mini          Camera                  Blink Mini
 192.168.1.112  alex-phone          Phone / tablet          iPhone / iPad
 192.168.1.130  raspberrypi.local   Computer                Raspberry Pi
 192.168.1.150  pihole              DNS server              Pi-hole
 192.168.1.196  Alex's MacBook Pro  Computer (this device)  MacBook Pro (M4)
 192.168.1.201  ..................  Computer                .........................
 192.168.1.203  ..................  ......................  .........................

14 devices on 192.168.1.0/24 (en0) in 2.0s

With -s, or after quitting the services view, the table lists services instead:

$ lsnet -s -l
 ADDRESS             SERVICE         HOST
 192.168.1.1:53      DNS             Home Router
 192.168.1.1:80      HTTP            Home Router
 192.168.1.1:443     HTTPS           Home Router
 192.168.1.8:80      HTTP            Brother HL-L2350DW
 192.168.1.8:443     HTTPS           Brother HL-L2350DW
 192.168.1.8:9100    printing        Brother HL-L2350DW
 192.168.1.14:22     SSH             diskstation
 192.168.1.14:80     HTTP            diskstation
 192.168.1.14:139    NetBIOS         diskstation
 192.168.1.14:443    HTTPS           diskstation
 192.168.1.14:445    SMB             diskstation
 192.168.1.14:5001   HTTPS           diskstation
 192.168.1.14:32400  Plex            diskstation
 192.168.1.88:80     HTTP            kp115
 192.168.1.130:22    SSH             raspberrypi.local
 192.168.1.130:1883  MQTT            raspberrypi.local
 192.168.1.130:8123  Home Assistant  raspberrypi.local
 192.168.1.150:22    SSH             pihole
 192.168.1.150:53    DNS             pihole
 192.168.1.150:80    HTTP            pihole
 192.168.1.201:3389  RDP             ..................

14 devices on 192.168.1.0/24 (en0) in 2.0s

Device names

The NAME column shows the friendliest name a device gives itself, in this order:

  1. A name someone set in its app or settings, from AirPlay, HomeKit or Cast ("Living Room", "Office speaker")
  2. Its primary .local hostname, kept whole ("octopi.local", "homeassistant.local")
  3. A generic service or UPnP name (a file share, a printer queue, "Home Router")
  4. The host part of its DNS name from your router ("fhrouter")

When MAC vendors are known (always on Linux and Windows, and with sudo on macOS), the column becomes NAME/VENDOR. A device with none of the names above shows its manufacturer instead, in regular weight rather than bold, so you can tell it apart from a real name:

$ sudo lsnet
 IP             NAME/VENDOR        TYPE            MODEL                  VENDOR         MAC
 192.168.1.52   Living Room        TV / streamer   Apple TV 4K (3rd gen)  Apple          f0:18:98:3c:62:8d
 192.168.1.77   Espressif          IoT device      Espressif              Espressif      24:0a:c4:1d:9e:02
 192.168.1.130  raspberrypi.local  Computer        Raspberry Pi           Raspberry Pi   b8:27:eb:5a:11:c4
 192.168.1.144  .................  Phone / laptop  .....................  (private MAC)  3a:91:5c:e2:07:1b

Empty cells are filled with dimmed dots, so even a row with little information is easy to follow from its IP address across to the columns on the right.

.local names are shown in full because you can use them directly, even when the device's IP address changes. Try http://octopi.local in a browser, or ssh pi@octopi.local. Machine-generated names like 36814e2569ca121f.local are hidden. Run lsnet --json to see every name a device reported, including its .local hostname under mdns.hostname.

Which network it scans

By default, lsnet scans the network of the interface your internet traffic uses. It takes the size from the interface's subnet mask (the /24 in 192.168.1.0/24):

Your network What lsnet scans
/22 or smaller (up to 1,022 addresses, including every home /24) The whole network
Larger than /22 (for example a /16 on an office or campus network) Only the /24 around your own address, so the scan stays at about two seconds

When it narrows a large network, lsnet says so under the results:

10.0.0.0/16 is large; scanned only the local /24 (--net 10.0.0.0/16 scans all of it)

To scan something else, give the network with --net (or -n) in CIDR form:

lsnet --net 10.0.0.0/16        # all of a large network (65,534 addresses)
lsnet --net 10.0.4.0/22        # just one part of it
lsnet --net 192.168.1.128/25   # the upper half of your /24
lsnet --net 192.168.20.0/24    # another subnet, such as a VLAN behind your router
  • Size. The largest network --net takes is a /16. Host bits are ignored, so 192.168.1.7/24 means 192.168.1.0/24. Up to a /22 takes about two seconds.
  • Your own network, or part of it. Everything works as usual: ARP, Bonjour, UPnP, names and MAC addresses.
  • Larger than a /22, on your own network. Use sudo on macOS and Linux (or setcap, see Running without sudo). lsnet then sweeps ARP first and probes only the devices that answer, so a /16 takes about ten seconds. Without it, every address gets probed: a /20 takes about five seconds and a /16 about a minute and a half. On Linux, devices may also go missing, because the kernel tracks only about 1,000 addresses at once (lsnet says so under the results). Reverse DNS lookups wait until the devices are found, and Bonjour isn't asked about every address. On Windows, the ARP sweep is replaced by reading the ARP cache after the port probe.
  • Another network through a router. Bonjour, UPnP and ARP don't cross routers, so lsnet finds devices only by their open ports, and shows no MAC addresses and fewer names. It says so under the results. Devices behind a firewall that drops these probes won't show up.
  • Which interface. Without -i, lsnet uses the interface on the network you gave, if there is one, and otherwise the one your internet traffic uses.

How it works

lsnet runs these at the same time:

Source What it finds Needs root
ARP sweep Every device that has an IP address, including ones with no open ports, plus its MAC address yes (or CAP_NET_RAW on Linux); no on Windows
ARP cache MAC addresses the kernel learned during the scan, including devices the sweep missed no on Linux and Windows; on macOS, root or a Developer ID–signed binary
TCP probe Live hosts, since even a refused connection proves a device is there. Every host that answers is then checked for common server and homelab ports (databases, Proxmox, Home Assistant, Plex, Jellyfin, RDP) no
Ping Devices that ignore every TCP port but still answer ICMP echo (macOS; on Linux and Windows ARP already covers them) no
mDNS / Bonjour Friendly names ("Living Room") and model identifiers from TXT records (AppleTV14,1, Chromecast md=, printer ty=, HomeKit categories), plus each device's primary .local name from a reverse lookup of its address no
SSDP / UPnP Manufacturer, model and name from each device's UPnP description, which is how routers, TVs and NASes usually identify themselves no
Reverse DNS Hostnames from your router's DHCP leases no
HTTP banner Server header and page <title> from web UIs no
TP-Link Kasa The names plugs, switches and bulbs were given in the Kasa app, and their models, from a UDP broadcast no

Then it classifies each device using the most specific evidence available: what the device says about its own model, then naming conventions, then web banners, then advertised services, then open ports, then the MAC vendor. The vendor database comes from the IEEE registry and is built into the binary, so no network lookups are needed.

Running without sudo

Without root, lsnet can't send its own ARP packets on macOS or Linux. It finds devices with the TCP probe and the discovery protocols instead, and how much else you get depends on the OS:

  • Linux: almost nothing is lost. The TCP probe makes the kernel look up the MAC of every live address, and lsnet reads the results from /proc/net/arp. That gives MACs and vendors, and even finds devices with no open ports.
  • macOS: recent versions don't let binaries that aren't signed with a Developer ID read the ARP table or MAC addresses, even through arp. Without sudo, the VENDOR and MAC columns are hidden, devices are identified from what they announce, and devices that are silent, fully firewalled and ignore pings are missed.
  • Windows: nothing is lost, and there's no need to run as administrator. Windows sends ARP requests on anyone's behalf, so the full ARP sweep always runs.

On Linux, you can give the binary raw-socket access once instead of using sudo every time:

sudo setcap cap_net_raw+ep "$(which lsnet)"

Firewalls

mDNS and SSDP replies come back to lsnet as unicast packets from each device. A host firewall that blocks unsolicited incoming UDP can silently drop them, for example ufw or firewalld with default settings on some Linux distributions. The scan still works, but names and models will be missing. If lsnet -v shows no SERVICES for devices you know advertise them, check the firewall. On Windows, that means making sure the network is set to Private rather than Public.

Output fields

In --json, each device includes:

Field Meaning
ip, mac, vendor Address, hardware address, and manufacturer from the MAC prefix
name The friendliest name the device gives itself
type, model What lsnet thinks the device is
hostname Reverse DNS name
randomized_mac The device uses a private, per-network MAC (typical of phones and laptops)
open_ports Which of the probed ports are open. Every address is checked for 22, 80, 443, 445, 7000, 8008, 9100 and 62078, and every live device also for 21, 25, 53, 110, 111, 135, 139, 143, 993, 995, 1433, 1521, 1883, 3306, 3389, 5001, 5060, 5432, 5672, 6379, 8000, 8001, 8006, 8080, 8081, 8096, 8123, 8443, 8888, 9090, 9091, 9443, 27017 and 32400
gateway, this_device Your router, and the machine running the scan
mdns, ssdp, http The raw evidence: Bonjour services with their TXT records and ports, UPnP description fields, web banner

Limitations

  • IPv4 only. Networks larger than /22 are narrowed to your local /24 to keep scans fast, unless you ask for more with --net (see Which network it scans).
  • Identification is heuristic. Devices that announce nothing and have no open ports show up with no type. Running with sudo at least adds their vendor, in the NAME/VENDOR column.
  • The Linux ARP cache can be stale. Entries for devices that just left the network can linger for a few seconds after they disconnect.
  • Sleepy devices can be missed. Phones and IoT devices in Wi-Fi power-save mode may not answer within the default window. Use -t to wait longer.

Updating the vendor database

MAC vendor names come from Wireshark's copy of the IEEE OUI registry, cleaned up (for example "Apple, Inc." becomes "Apple") and stored in data/oui.tsv along with a license header (see Third-party data). To refresh it:

python3 scripts/update-oui.py

Wireshark updates the database weekly and asks that it not be downloaded more often than that.

Contributing

Better identification rules are the most useful contribution. If lsnet leaves a device's type blank or gets it wrong, open an issue with the output of lsnet --json for that device, with anything private removed. The rules live in src/classify.rs.

License

Copyright (C) 2026 Sanford Lincoln

lsnet is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See LICENSE.

Third-party data

data/oui.tsv, the MAC vendor database built into the binary, is derived from Wireshark's manuf database. Wireshark generates that database from the IEEE OUI registries. The file is Copyright 1998 Gerald Combs and contributors and is licensed under GPL-2.0-or-later, which allows it to be redistributed as part of lsnet under GPL-3.0-or-later.