How does an equipment knowsknow it has some devices connected to it?

I was wondering how an Ethernet equipment (for example a switch) knows that something have been plugged in and is Upup ?

Is there a pair of copper wire dedicated for that ? Or ana bit exchange ? On which wire ?

Thanks for your answer.

Bumped by Community user

occurred Sep 27, 2017 at 21:19

Bumped by Community user

occurred Aug 28, 2017 at 17:44

Bumped by Community user

occurred Jul 29, 2017 at 16:50

Bumped by Community user

occurred Jun 29, 2017 at 16:18

Source Link

asked May 30, 2017 at 9:46

How does an equipment knows it has some devices connected to it?

I was wondering how an Ethernet equipment (for example a switch) knows that something have been plugged in and is Up ?

Is there a pair of copper wire dedicated for that ? Or an bit exchange ? On which wire ?

Thanks for your answer.