Can Russia be cut off from the internet? [closed]

A great variety of sanctions have been discussed and implemented with more to follow.

One sanction I have never heard being discussed, and that is cutting off Russia from the internet.

Now I am aware that there is no a single organization that controls the internet. But when it comes the management of the top-level domains there are not many options available, and some of this is definitely controlled from the US.

I appears to me that cutting of Russia from the internet would make the lives of Putin and his government harder and it would also help create an atmosphere of discontent inside Russia towards Putin. In addition it would also have an economic impact on Russia's economy.

Can it be done and would it support Putin or hurt him?