What happens if I connect a provider and a cable to my switch at both ends?

Question

Computer networks

Answer 1

A ring is formed in the network, it will start to hang and blunt
As soon as the provider determines which subscriber screwed up, he will simply cut you off from the network

Answer 2

internet freezes

Answer 3

For the provider (normal) - nothing.
For you - tyrnet will be lost :)
Do you want to arrange a dirty trick on your neighbor? :)