In productionProbeginnerSocketCAN state

The CAN device exists but sends nothing

Bring the configured interface online without changing the application.

Pairs with SocketCAN and bus diagnostics in Hardware Integration & CANopen. Read the concept first, then diagnose it here.

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Operator report

`can0` appears in `ip link`, but transmit calls return network is down.

Ubuntu 24.04, ROS 2 Jazzy, SocketCAN vcan, CANopen drive simulator, ros2_control

System boundary

Trace only the relevant path.

Linux can0 devicelink stateCAN application

How this lab works

You diagnose it — no command list.

Open the repair workspace and gather your own evidence in a real terminal. No diagnostic commands are handed to you — finding the fault is the exercise. Stuck? Progressive hints unlock inside the workspace.

Verification

Your repair must pass more than the visible symptom.

Interface is UP
Heartbeat frames receive
Hidden regression behavior
Root cause explanation