How do I play audio though jackd from console?

OSS        | play
ALSA       | aplay
PulseAudio | paplay
JACK       | ?

What tool can I use to test if jackd is properly configured and make it play something?

Solution 1:

There are many Jack compatible media players, such as mpv (ffmpeg based) and vlc. See this List of Applications

Try mpv --ao=jack test.wav

As well, the jackd2 package in Ubuntu 14.04 comes with a sample program called jack_simple_client which generates a test-tone output.