[SOLVED] How to proceed in order to shutdown network using an Arduino?

Hello guys!

So I'm using an Arduino to shutdown the power of a computer using relays when I send some code.
Now I want that Arduino to do the same thing, but relative to the network I'm using on that computer.

Could you give some hints please?

Thank you

Hi,

What is the network type, location, size?? Other nodes?

What do you mean "Shut down the Network"??

Easy to power off routers, switches... is that what you mean?

My Arduino sends some codes to a stb (set-top box), where it can change between channels, open menu, ... via an IR emitter. The stb is connected to a power source together with the arduino relays, in order to power it off/on when I want.
The stb is also connected to my router with an Ethernet cable, and it's that connection that I want to cut off when I want, so that the stb can't receive any image or sound.