@joshiey that is your Remote Supervisor Adapter port. Amongst other things it allows you to
* Automatic notification and alerts
* Automated Server Restart (ASR)
* Continuous health monitoring and control v Domain Name System (DNS) server support
* Enhanced user authority levels
* Independent power, which enables around-the-clock access to the server even when the server power is off.
for all the information about that, download the installation guide [https://www.ibm.com/support/pages/ibm-remote-supervisor-adapter-ii-slimline-and-remote-supervisor-adapter-ii-installation-guide-servers|from here]