a pocket network tester for Linux

Plug a cable in.
Ask the cat.

fluGATO tests the cable port on your laptop the way a pocket tester would: link speed, DHCP, gateway, DNS, internet, and which switch port and VLANs you just landed on. In your terminal, in about four seconds. Judged by a chonky orange tabby who takes the results personally.

curl -fsSL https://flugato.com/install | sh

no root neededone file in ~/.local/binLinux x86_64 / arm64needs python3MIT

Then flugato. Later, flugato update. Changed your mind: flugato uninstall, and it is gone without a trace.

no link, so the cat sleeps. move the pointer to shine a laser. tap the cat to poke it (it will not love that).


      
    

  

  

    try a result:
    
    
    
    
    
  







  
Nine rows. One verdict. One cat.

  
Top to bottom, the order you would debug it in. Green, amber or red; the banner says it in words, the cat says it in cat.

  

  

    
The cat sitting, eyes happy, mouth in a small cat smile.
● all good

    
The cat sitting with one eye squinting and a blue sweat drop by its ear.
● check warnings

    
The cat startled: ears flat, eyes wide, mouth open, an exclamation mark beside its head.
● problem found

    
The cat sitting, eyes looking to the side.
● testing…

    
The cat lying flat in a loaf, eyes closed.
● no link

  







  
Testing a cable should never cut your own connection.

  

    

      
flugato

      
no root: reads what the computer already knows

      
    
        
  • link speed and duplex from the driver
    • 
        
  • the address NetworkManager got, and its lease
    • 
        
  • gateway ping, DNS, internet
    • 
        
  • switch, port and VLAN rows say needs root
    • 
      

      
Nothing is configured, nothing is changed. Press s for the rest.

    

    

      
sudo flugato

      
root (press s in the app, or sudo ~/.local/bin/flugato): the test ports get their own network namespace

      
    
        
  • a fresh DHCP offer, timed
    • 
        
  • the switch and port over LLDP and CDP
    • 
        
  • a DHCP probe on every tagged VLAN of a trunk
    • 
        
  • b blinks the port LED so you can find it in the rack
    • 
      

      
The test port's address, routes and DNS never reach the rest of the machine. Your Wi-Fi, your VPN and the SSH session you are typing in stay exactly as they were.

    

  

  
Two cable ports (a USB adapter counts) give you a cable test: both ends of a patch cord in the tester, test frames both ways, the CRC counters watched. The pocket tester also sits inline between a device and the switch, with a capture you can open in Wireshark; that part has not made it into the terminal app yet.







  
Scriptable, for the days you have forty ports to do.

  
Every mode writes to stdout and means its exit code.

  
$ flugato --once
fluGATO 0.4.0 · enp3s0 · 2026-10-14 14:02
● LINK      1G Full
● IP        192.0.2.57/24
● DHCP      from 192.0.2.1  lease 12h
● GATEWAY   192.0.2.1  0.9 ms
● DNS       192.0.2.1  14 ms
● INTERNET  host.example:443  38 ms
● SWITCH    access-sw-02  192.0.2.250  (LLDP)
● PORT      Gi1/0/14  desk 3B west wall
● VLAN      70 native  trunk 10 VLANs: 10, 20, 30, 522 +6
ALL GOOD 9 checks in 4.1 s

$ flugato --once --json | jq -r '.verdict, .rows.LINK.value'
ALL GOOD
1G Full

$ flugato --once --quiet --port enx3c18a0 || echo "port 14 needs a look"
port 14 needs a look

$ flugato --watch --port enp3s0     # one line per change, for a tmux pane
14:20:02  ● link up 1G Full
14:20:06  ● DHCP 192.0.2.57/24 from 192.0.2.1
14:31:40  ● link down
14:31:44  ● link up 100M Full: both do 1G, check the cable

  

    
--once
run the checks, print the rows, exit

    
--json
the same, as one JSON object

    
--quiet
say nothing; the exit code is the verdict

    
--watch
stay, and print a line whenever the port changes

  







  
The screens

  
A full-screen terminal app with single-key commands. It follows your terminal's colours, so it is at home in a dark one and a light one.

  

    

      
        
        The dashboard: a green ALL GOOD banner, nine green rows from LINK to VLAN, a list of recent tests and the cat in the corner.
      
      
Dashboard: the verdict, the rows, recent tests, the cat.

    

    

      
        
        The VLANs screen: a trunk with native VLAN 70 and ten tagged VLANs, each with a DHCP probe result and the address it offered.
      
      
VLANs: one DHCP probe per tagged VLAN, from a throwaway MAC.

    

    

      
        
        The ports screen: the cable port, a USB adapter as a second port, and the Wi-Fi connection marked never touched; the cat asleep with z's.
      
      
Ports: pick the test port. Your own connection is never touched.

    

    

      
        
        The dashboard without root: an amber CHECK WARNINGS banner, the link row warning that both ends do gigabit, and the switch rows saying needs root.
      
      
Without root: what the machine already knows, and a hint for the rest.

    

    

      
        
        The cable test: both ports linked at 1G, twenty thousand frames each way with none lost, no CRC errors, cable passes.
      
      
Cable test: a patch cord between two ports, frames both ways, the CRC counters watched.

    

    

      
        
        The installer in a terminal: it checks python3, iproute2 and ethtool, downloads one file, verifies its checksum and installs it to ~/.local/bin.
      
      
The installer: checks, downloads one file, verifies the checksum, done.

    

  







  

    
It started as a thing in a pocket.

    
fluGATO was first a hand-held tester: a Raspberry Pi with a 3.5-inch touch screen in a 3D-printed holder, on a USB power bank. Plug a cable in and the screen fills with the same rows; tap to re-run, hold to blink the port. With no cable it shows the cat asleep in the server closet, and between tests it becomes a desk clock with the weather, the cat in sunglasses or under an umbrella as the forecast says.

    
The terminal app is the same tester with the laptop you already carry as the hardware. The cat came along. Of course the cat came along.