There is a good software that will scan your computer network, whether home or office, 
and provide a thorough inventory list. Advanced LAN Scanner will scan all of your computers, tell you the IP address, any shared folders, what services are running, usernames, and if any ports are open.
Not only will you get a good inventory of who is logged onto which computers, you’ll see which ports are open. Finding an open port is crucial so you can close it up with a firewall for security purposes. You should use the scanner for a good easy way to scan your network and shore up any computer vulnerabilities. Plus, it’s free!