Depict Adress Resolution Protocol using Mirobits
Excerpt from The micro:bit Software Ecosystem: 

Typically, a program is written on the host computer and then transferred to the micro:bit over USB. There are actually two chips on the micro:bit, one that is running software entirely to facilitate the flashing (the KL26Z) and one that actually runs the user’s code (the nRF51822).

So your user program is executed on the NXP nRF51822. This is a radio module used to make wireless connections with devices using the 2.4GHz ISM radio band. Each of the NXP nRF51822 radios should have a unique address. These addresses, previously known as a MAC (Media Access Control) address now called EUI (Extended Unique Identifiers) are  assigned by the IEEE Registration Authority.

Your assignment appears to be to create programs for two micro:bit devices. One as a requester, the second a responder. The requester sends a message to ask for the IP and EUI of the other device. The responder answers with the an IP address and a EUI address you have hard coded. Then you are to revise your code to discover the unique address embedded in the responders micro:bit and supply that in place of the hard coded one.