What to Do With Unknown Devices in Spiceworks

It happens. Spiceworks does a great job of figuring out which devices on your network are printers, desktops, servers, etc. But sometimes, even Spiceworks can't tell what some devices are. Now if you set up the entire network yourself, then you probably don't need to be told what those devices are. One look at the IP address and you probably know. But if you inherited your network from the previous afraid-to-take-notes tech or if you outsource your WAN administration, then there are bound to be some devices you don't recognize.

Here's one way to get some info on those wayward devices:

1. Download Nmap. You should already have it. Why? Nmap can tell you a lot about what is on your network. So when rogue devices show up on your network, you can arm yourself with valuable knowledge about the device before you locate it and shut it down.
2. Extract Nmap. I'll use c:\nmap in this example. (Notice that I am also assuming that you are running Windows.)
   
3. Open a command prompt and change to the c:\nmap folder.
4. Enter nmap -v -v -O --osscan-guess x.x.x.x -oL c:\nmaplog.txt
   --- Replace x.x.x.x with your IP range (i.e. 192.168.0.0-254). CIDR notation is acceptable (i.e. 192.168.0.0/16).
5. Hit the Enter key and wait.
6. When the scan is finished, you can open c:\nmaplog.txt in your text editor and view the details on each device. You should see the type of device and the OS. Along with the IP address, this is often enough information for me to figure out what kind of device I'm looking at.
7. Reclassify the device in Spiceworks.
8. Start a document noting all printers, servers, routers, switches, and such so that you can just refer to the list the next time you don't recognize a device. I recommend keeping a separate list from Spiceworks for redundancy.

Obviously, this is only one way to learn what is running on your network. What other suggestions do you have?