A forwarder that accepts data from other forwarders and sends the data to a Splunk deployment. If you are forwarding data to Splunk Cloud, you can use a gateway forwarder to minimize the number of ports you must open in your corporate firewall. If you want to anonymize data before sending it to your Splunk deployment, this configuration enables you to create a single point at which all anonymization occurs.
For more information
In the Splunk Universal Forwarder Forwarder Manual