This data allow conection between arduino and app, for each arduino with network card we need to configure the following data.

Ethernet shield type.

It defines the network card installed in our arduino, compatible with network cards based on the w5100 chip (wired network card) and official arduino wifi shield.

IP adress.

This is a numeric label that serves to identify a device (communication / connection element) of a device within a network.
For example, you can use 192.168.1.200 or 192.168.0.200.
You need adapte it about your network setting.

UDP (User Datagram Protocol)

Default 5000, is the “way” through which they are going to send the data, it is a numerical value, to facilitate the external connection to your local network, the ideal is that of values ​​different to each arduino.

 

Mac Address:

In theory it is an identifier that corresponds uniquely to a network card or device,  therefore we should never put two equal addresses to our equipment.
In the original Ethernet Shield the mac is printed on a label, in a clone put a random one, being careful not to repeat it.