Question: We have an IP address in configuration file (which hosts a solr server that accepts requests at a specific port). The developer who has added that IP address in the configuration file in the source code has left the company. I feel that it might be an EC2 instance, how-ever when I logged into EC2 dashboard, I don't see any with that IP address. Perhaps, I didn't check at all the places that I need to. 
How can I find if that ip address is an EC2 instance.

Answer: 
You could run `nslookup <ip address>` in the terminal. If it's an ec2 IP address will have a name like ec2-ip.instance\_location.compute.amazonaws.com.
I believe the easiest way to determine this is to crossreference your IP with Amazon's public IP list.

You can start here:

<https://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.html#aws-ip-download>