Detect if an IP address is running a Bitcoin node

Question

Is there a way to detect if an IP address is running a Bitcoin node? Maybe I can extract the IP information from the blockchain somehow?

Answer 1

There are many ways to do this.

Pretty reliable and relatively simple way is to get the list of Bitcoin nodes from https://api.blockchair.com/bitcoin/nodes . It is the JSON object that looks like:

{"data":{"nodes":{"1.234.63.142:8333":"version":"\/Satoshi:0.16.0\/","country":"KR","height":588031,"flags":1037},
"1.36.226.179:8333":{"version":"\/Satoshi:0.18.0\/","country":"HK","height":588031,"flags":1037},
"100.12.85.110:8333":{"version":"\/Satoshi:0.16.2\/","country":"US","height":588031,"flags":1037},
...

And then check if IP address in question is present in this list.