First came NetBIOS, or Network Basic Input/Output System, developed by IBM back in the later seventies. It was developed in the PC environment and let programmers develop Client/Server applications, but was really developed for peer-to-peer environments. Naming conventions using NetBIOS were unique because of the browsing capabilities in networking. If you are running a Unix environment, you have no capabilities like what NetBIOS can give you, as well as a complete Novell environment. Actually, it was greatly enhanced by IBM with extended features and was renamed to NetBEUI, or NetBIOS Extended User Interface.

There are a few problems, of course, with NetBEUI. One is that it is not routable. With that restriction, it is only good for a network of a few hundred machines. It uses a token ring type of source routing. In other words, the name is passed on to each machine in broadcasting through the network. However, if you have a machine on the other side of the router, you will not be able to see these machines. That is because NetBEUI does not work in a WAN. For example, TCP/IP naming conventions are like "Sparky.ACME.COM" which, using DNS, is translated to maybe 192.168.217.34. Or maybe an alias for that same machine, which is www, so when you type "www.acme.com" you get the Web pages that are located on the Sparky machine. However, if you are browsing your machines through your local area network, you see a different name for Sparky, which might be called "Server1" in that environment. Server1 is the NetBIOS name for the same machine. If you want to see that machine and maybe share printers and drives from that machine, you have to use NetBEUI's functions.

3Com and Microsoft developed a product called LAN Manager in the mid-eighties, to run on IBM's OS/2 as a process, and slightly changed the way it worked, but both used NetBEUI. However, the problem still existed that you could not see a NetBEUI machine name across the router. So in 1993, Microsoft extracted NetBIOS from NetBEUI in order to bind it to a TCP/IP protocol so you can see these machines across the router. Two years later they did the same thing but bound it to IPX/SPX for Novell's protocol. There are still limitations, though. It still does more broadcasts than TCP/IP.

The actual NBTSTAT command is used to show your network statistics using NetBios over TCP/IP. One of NetBIOS's functions is that it keeps a name table. You can display this table with one of the features of the NBTSTAT command on either your own machine or a remote machine! You can display the cache on either your own machine or the remote machine. You can display resolved names, if you like. Or you can just look at the sessions that your adapter has, listing the names in that session table. If you are having problems, you can purge the tables and reload the names. All of these switches are for diagnosing problems on your network. Here is an example of using NBTSTAT on Sparky:

C:\WINNT\system32>nbtstat -a Sparky
    NetBIOS Remote Machine Name Table
Name            Type             Status
--------------------------------------------
SPARKY        <1F> UNIQUE      Registered
SPARKY        <00> UNIQUE      Registered
SPARKY        <20> UNIQUE      Registered
ACMENETWORK   <00> GROUP       Registered
ACMENETWORK   <1C> GROUP       Registered
ACMENETWORK   <1B> UNIQUE      Registered
SPARKY        <03> UNIQUE      Registered
SPARKY        <BE> UNIQUE      Registered
ACMENETWORK   <1E> GROUP       Registered
INet~Services <1C> GROUP       Registered
IS~SPARKY.....<00> UNIQUE      Registered
ACMENETWORK   <1D> UNIQUE      Registered
..__MSBROWSE__<01> GROUP       Registered
SPARKY        <6A> UNIQUE      Registered
SPARKY        <87> UNIQUE      Registered

   MAC Address = 00-10-4C-34-DA-A7

If you noticed, the results even show you the MAC Address for that adapter. If there had been a conflict, it would have showed up here instead of the registered result.

Try this utility and we'll see you next month!