gianry nella mia distro speedtest e` un link a /usr/bin/speedtest-cli, e non supporta il parametro -s:
$ speedtest-cli -s 38092
usage: speedtest-cli [-h] [--no-download] [--no-upload] [--single] [--bytes] [--share] [--simple] [--csv] [--csv-delimiter CSV_DELIMITER] [--csv-header] [--json] [--list] [--server SERVER] [--exclude EXCLUDE] [--mini MINI] [--source SOURCE]
[--timeout TIMEOUT] [--secure] [--no-pre-allocate] [--version]
speedtest-cli: error: unrecognized arguments: -s 38092