I have one arduino and ethernet shield, but sometimes I have no idea what happens.
I have that same problem after drinking too much.
every time that I try to compile a sketch, these LED's turn off and back to turn on, gave the impression that it would be kind of a reset on the shield. Anyone have an idea ..?
They should do that. The shield, and the Arduino, are reset when a sketch is uploaded.
Ps: Rx Tx does not even blink when I turn on feeding (this is normal?)
I don't even know what this means. What are you feeding? What are you feeding it?
The Rx and Tx lights have nothing to do with ethernet communication, so expecting them to do something when the ethernet shield receives input/sends output is not a realistic expectation.