I have a Jtrace which I use over ethernet.
Running nrfjprog shows:
nrfjprog -f nrf52 --eraseall
ERROR: No debuggers were discovered.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.
Even if I add "--snr XXXXX" it won't connect to it, and listing devices returns an empty list. Of course, JLink Commander connects fine as long as I select the JTrace (for instance, by specifiying its serial number)