make a connection through network using Arduino

hi everyone , i want to make a connection between two Arduino,
using the Ethernet shield
what i really want to do is
each Arduino has a push button,
when i press the button in the #1 Arduino
the LED on the #2 Arduino will be on
and the same on the other side

i need guidelines to start
thx.

i need guidelines to start

You need to start with understanding that an Arduino with an ethernet shield can be a server, responding to requests, or a client, making requests.

It is possible for an Arduino to act as both server and client.

Look at the examples that come with the Ethernet library. Get one Arduino acting as client, making GET requests to the other Arduino, acting as a server. Make the server Arduino handle the GET request correctly.

Then, making the server act as a client, too, will be easy, and making the client act as a server, too, will be easy.