When using the native ping method (as recommended) instead of exec, telegraf is unable to ping when run as a non privileged user. The fix is simple but I always forget the command.

setcap cap_net_raw+ep /usr/bin/telegraf

internal server error

Another, unrelated issue I seem to have after updating telegraf is that it is unable to write to influxdb after the first lot of data and just keeps giving the error:

E! [agent] Error writing to outputs.influxdb_v2: failed to write metrics to bucket "telegraf/autogen": 500 Internal Server Error: internal error: An internal error has occurred - check server logs

and the influx logs show

 lvl=warn msg="internal error not returned to client" log_id=0zJxpJWW000 handler=error_logger error=EOF

This seems to be a bug in telegraf 1.35.0. 1.34.1 works fine.