.. _change_default_port: Changing the Default Port ------------------------- By default, H2O on Spark starts on the IP of the client node and the first free port starting at 54321. You can specify to use a custom port for H2O using the ``spark.ext.h2o.client.web.port``, as in below. Refer to :ref:`sw_config_properties` for a complete list of configuration properties. .. code:: bash ./bin/sparkling-shell --conf "spark.ext.h2o.client.web.port=443"