Hello I am trying to setup a dhcp3-server on Ubuntu. But my question is more generic, if dhcp server is in a blockbox and all clients are connected to it I think I get what is going on but when dhcp server is installed on one of the "clients" that confuses me.

When I send a dhcp packet from that client to the dhcp server, will my ethernet card read and write at the same time? Or will it handle it internally without writing any data to ethernet cable.

It's the first time I am encountering these network things so I am a little bit confused.

Also I wonder If I am in a big network with lan IP let's say 192.168.0.100 and I install a dhcp server to my computer, can any other computers accidentally get IP from my dhcp server? Every computer has one ethernet card (if that matters?). And every computer is connected to one router. I guess the answer is no because the broadcast message won't reach to my computer since when router receives a dhcp search packet it will answer and it won't let other computers know about it because they don't need to. And without router sending that packet one by one, it cannot travel further.

I'd be glad if someone enlightens me. Thank you very much.