This parameter is used in auto-install-scripts for the Universal Forwarder but I could not find any information about it in the documentation. Is this something used in older versions of Splunk?
The Linux-strings-command outputs "--auto-ports" in /opt/splunk/bin/splunk - so it is recognized (like e.g. --accept-license).
I believe that the auto-ports option still works in the latest version (6.6) of Splunk. What it does:
Splunk begins with the default port number for splunkd (8089 unless you have also changed the default). If that port is available, Splunk uses it for splunkd. However, if the port is not available, Splunk automatically increments the port and tries again (8090, 8091, etc.). It uses the first available port number that it finds.
This option is often used when installing the Universal Forwarder because we usually don't care which port is assigned to splunkd.
I believe that the auto-ports option still works in the latest version (6.6) of Splunk. What it does:
Splunk begins with the default port number for splunkd (8089 unless you have also changed the default). If that port is available, Splunk uses it for splunkd. However, if the port is not available, Splunk automatically increments the port and tries again (8090, 8091, etc.). It uses the first available port number that it finds.
This option is often used when installing the Universal Forwarder because we usually don't care which port is assigned to splunkd.
One additional question:
In the universal forwarder installation script this parameter is used in conjunction with "splunk set deploy-poll". Does this make sense? I would say this port is fixed/given by the configuration of the deployment-server.
No - the port given for the deployment server is the deployment server's management port. This is completely unrelated to auto-ports or the forwarder's own management port.
Thank you. I added some feedback to the respective documentation so this information could be added there.
Thanks for that feedback. We'll get the documentation updated with this information shortly.