[IPython-User] How to terminate running IPython kernel?

[klo uo]

If I execute this in terminal:

  $ ipython kernel
  [IPKernelApp] To connect another client to this kernel, use:
  [IPKernelApp] --existing kernel-4333.json

How can I terminate this kernel?

Ctrl+C, Ctrl+D, exit, quit, exit()... can't do it