I want to capture ethernet packets with my raspberry pi's ethernet port. I know I could create an ethernet bridge between two ethernet ports on the raspberry and analyze the packets internally with tcpdump. But I need the entire thing to not rely on the raspberry being on.
So I want to use an ethernet splitter to connect one end of the ethernet cable to the rasbperry. For this to work, the raspberry must do no low level ethernet stuff, it must only listen.
Is it possible?