Taking a quick look at an inventory of systems on a network is incredibly handy. Sure, there are plenty of tools to scour the network and give detailed reports about MAC addresses, IP addresses, hostnames, and other information. However, I have found that none of them are as quick and easy to use when only looking for NetBIOS (generally Windows systems) names than the Nbtscan NetBIOS name scanner program. I started using Nbtscan over six years ago and first shared the tool with TechRepublic in this blog about Nbtstat. The version has since updated with Nbtscan, and to this day, I don't know of a tool that will as quickly and easily assess the NetBIOS inventory of a specified subnet than Nbtscan. Let's take a quick look at how I use it to find information about Windows systems running on my network.
Nbtscan is available for Windows (as a DOS-only command), Linux, and SCO platforms as a command-line tool. I use the Windows version frequently, and even though Windows is supposed to stop using NetBIOS, it is still in use for default configurations for Windows Server 2008 and Vista. Further, Nbtscan has no problem picking it up. Nbtscan is a quick download at 36 K and has a number of options in the scan command. Here are my most common scan tasks — with this first example scanning a subnet with full information:
nbtscan-1.0.35.exe -f 192.168.1.0/24
This scan on my private network returns the following result:
This scan takes a little bit longer, as it is pulling MAC addresses, an inventory of NetBIOS-related services running, IP addresses, and domain membership for the hosts on the specified subnet. Another, more quick and easy scan is shown below, scanning only for the network presence and retrieving the MAC address:
nbtscan-1.0.35.exe -m 192.168.1.0/24
The result in this scan is a quick and simple list as shown below:
Nbtscan can cover even large subnets very quickly. I have routinely performed scans on many networks, including 16-bit subnets without issue. All great functionality aside, Nbtscan is not a monitoring solution, but is incredibly handy if you need to see where NetBIOS systems are on the TCP-IP networks. Nbtscan will also pass over systems without NetBIOS services running and not show them in the scan result. You can try, but I do not think you will find a quicker tool for the task than Nbtscan. Nbtscan is a available as a free download from Unixwiz.net.