Jumbo Frames enable you to send and receive larger network packages. It is a very useful feature for some applications (such as virtualisation).
Client, network switch and the network controller must be able to support this functionality.
To configure jumbo frames, connect your monitor and keyboard to the server and select option
Now you can see the overview of your network cards and their current Jumbo Frame Status …
Select the network card that you wish to configure …
Now you can configure the MTU value (please read the documentation of your NIC and Switch about supported values).