You will learn the IP address assigned to the development board by using the Console System Service.
In MHC's "Options" tab, expand the Harmony Framework Configuration > System Services > Console selection tree. Check the Use Console System Service? box, and configure it as shown below. Note the only selection you need to change is the Peripheral For Console Instance (USB_CDC_CONSOLE).
You've already configured the TCP/IP stack to send and receive messages using the Console System Service. Doing this automatically enabled the Command Processor System Service for you. Expand System Services > Command if you would like to verify this.
In MHC's "Options" tab, expand the Harmony Framework Configuration > USB Library selection tree. Note that MHC automatically checked the Use USB Stack? box for you when you enabled the Console System Service.
Expand the USB Device Instance 0 selection and configure it as shown. Note there are only three changes that need to be made.