If you are using the Ethernet Port to indicate connectivity to a back channel network connection, do the following tasks:
Read the following information about unmanaged devices in Adding and Removing Unmanaged Ethernet Devices in N1 Provisioning Server 3.1, Blades Edition, System Administration Guide.
Place the Ethernet Port in a location within the farm that gives you the easiest access to the critical servers.
Keep in mind how much access you are opening up between the farm and your organization, and apply restrictions where appropriate.