I can ping the the address 192.168.13.14. The documentation says:
The IP address for the Cube will be automatically set to the CubeNode’s IP address+1, which is 192.168.13.14+1 = 192.168.13.15.
However I cannot ping 192.168.13.15. So put a logic analyzer between cube node eth and cubepilot. But there is no communication at all. I tried with a second node but same, no communication. Both CTS and RTS are all time high (busy).
I think I have more a firmware or parameters issue. If someone who was able to get a success connection could share the firmware setting and also the parameters for the node and cube, I would be really happy.
Since you can ping 192.168.13.14, the Ethernet side of the CubeNode seems alive. The issue is probably on the PPP/UART side between the CubeNode and the Cube.
Please check the Cube firmware and parameters first:
assuming the CubeNode UART is connected to Serial2. Also confirm the Cube is running ArduPilot 4.5+ and that the selected serial port supports RTS/CTS flow control.
If RTS/CTS remain high and there is no serial activity, I would strongly suspect either the wrong Cube serial port is configured, TX/RX/RTS/CTS wiring mismatch, or PPP not actually enabled on the autopilot firmware/port.