I need to program a server, capable of storing information, sending and receiving information to manage bookings in a high school canteen. I use byte-type information that I store in a table, I can read it and edit it, that’s fine. But for Ethernet communication, I have no idea how to do it, despite several hours spent documenting myself on the Internet. If someone could help me or explain my problem to me, that would be very helpful.
Put the Arduino away for now. Use two PCs - one acting as a web server, the other acting as a client (using a browser). The client makes GET requests. This can be done using a browser, by combining the protocol, the server name, the script to execute, and the script data, into one URL.
For example, if the protocol is https, the server is www.google.com, and the script is search, and the data is q="smith & wesson", the URL would be:
You need to define the protocol (most Arduinos only do http), the server (that's your server), the script (often a php script) to execute, and the names of the variables that the script expects to be valued.
The Arduino would connect() to www.google.com, and make a GET request that looks like:
GET search?q=smith+%26+wesson HTTP/1.1
and would then define a host header:
Host: www.google.com
You've provided way too few details about what you are trying to do to get any real help.
// use the numeric IP instead of the name for the server:
IPAddress server(10,51,6,100); // server ip set more two place
//self IP
IPAddress ip(10, 51, 6, 50);
IPAddress gateway(10, 51, 6, 1);