How to track ethereum nodes with using geth or other client?

Question

I want to track Ethereum nodes, like the Ethereum node tracker at etherscan.
I want to get information about all Ethereum nodes. For example, total number of Ethereum nodes, total number per country, OS type, etc.
I have searched the web but have not found a way to do this.
Can I get information about other Ethereum nodes by using a library such as web3js to access Geth or other clients?
Or does Etherscan use its own software?

Answer 1

You can check all that stuff via etherscan by going on to the following address

https://etherscan.io/nodetracker/nodes

Furthermore you can filter the node by OS, Country and Type of the node.