Operating Systems of Devices on Network- How to get useful information?

I don't know if what I want to do is possible. My goal is to detect what devices are connected to my network and push that to Splunk for further analysis. I want to get information that can identify what the device is. For example, I detect that 192.168.86.100 is a Windows 10 laptop, 192.168.86.101 is a windows 2012 server, and 192.168.86.102 is an iPhone 6.

What tools do you know of that can get this information? Is nmap -O and creating a log with that the best way?