eLux® Diagnostic Tools

Last published : Oct 16, 2026
eLux includes a set of Linux diagnostics tools — lsof, fuser, ping, and tcpdump — for investigating system and networking issues directly on the device, without escalating to a support case. It also supports automatically recording network traffic from the moment a device boots, for troubleshooting connection problems that happen before anyone can even log in.
Related information
Short guides

Available Tools

Four command-line tools are available for investigating problems directly on the device:
Tool Purpose Access
ping Checks whether another device or server can be reached over the network. A full iputils binary, not the busybox applet. Non-root elux user
lsof Lists open files and file descriptors — useful for seeing which running program has a particular file open. Non-root elux user
fuser Identifies which process is using a file or socket — useful before unmounting or deleting something. Non-root elux user
tcpdump Records raw network traffic (a "packet capture") so you can see exactly what data was sent and received. Root only, by design
All four are available since eLux 7.2607, but two need an extra package before they'll show up on a device:
  • ping ships in the base baseos package — no extra step needed.
  • lsof and fuser need the baseos_extra_tools feature package (FPM).
  • tcpdump needs the admin_tools package, feature package admin_tools_tcpdump_boottime.
  • Adding these feature packages may require modifying the image definition file on the web server via ELIAS.

Boot-Time Network Capture

Instead of waiting for someone to notice a problem and manually start a capture, eLux can record network traffic automatically, starting from the moment the device powers on — early enough to catch connectivity or configuration issues that happen before a user can even log in, for example during 802.1X authentication. While a capture is running, a desktop notification tells the signed-in user their traffic is being recorded.
Set the following in /setup/terminal.ini, section Global, using Scout → Advanced device configuration → Advanced file entries:
Key Value Description
BootTimeNetCapture true Enables boot-time capture. Case-sensitive — only lowercase true is accepted; any other value, including TRUE, is treated as disabled, and the device still boots normally.
BootTimeNetCaptureMaxFileSize Size in MB, for example 10 Maximum size per capture file before it rotates.
BootTimeNetCaptureMaxFileCount Number of files, for example 2 Maximum number of rotating capture files kept at once.
Add each entry, then click Apply and reboot the device.
Capture files are written to /tmp/boottime.pcap0, /tmp/boottime.pcap1, and so on, rotating once a file reaches the configured size — the oldest file is overwritten once the file count limit is reached. Capture continues seamlessly across LAN/WLAN interface switches.

Useful Commands

What Command
Check tool availability which ping lsof fuser tcpdump
Confirm ping is the real binary, not busybox file $(which ping)
List boot-time capture files ls -la /tmp/boottime.pcap*
Check whether boot-time capture is running ps aux \| grep tcpdump
Verify boot-time capture settings ucsettingsctl -o Global
Live capture (root) tcpdump -i any -c 10
Capture to file (root) tcpdump -i any -w /tmp/networktrace.pcap -c 50
Read a capture file tcpdump -r /tmp/networktrace.pcap \| head
List open files for a path lsof /home/elux
List network connections lsof -i
Show processes using a path fuser /home/elux/

Good to Know

  • Capture files in /tmp are owned by root — exporting one to USB requires sudo cp.
  • Boot-time capture files are included in Scout diagnostics packages requested from the device, and can be opened and analyzed in Wireshark.
  • Running tcpdump as the non-root elux user fails with Operation not permitted — expected, not a bug (see Access above).
  • If which tcpdump returns empty, that's expected on a device without the admin_tools package — not a fault.