Networks

Here's a very good article on the subject (pros and cons) and it takes you to a link that tells you specifically how to do this via your DHCP server:

http://www.petri.co.il/disable_netbios_in_w2kxp.htm

Hate to tell you this, but anytime you get something that "should" work, what is really being said is "This should work in most normal situations. However, we have no way of testing every possible permutation that you are likely to experience. Therefore, we leave it up to you to test this in your specific environment. Good luck!"

Therefore that would be my suggestion: Set up a small test environemtn and see how this change affects that environment before going live on your entire network. That will be you ONLY surefire way to asses the impact on YOUR environment.

Good luck.

Since you have a mixed environment, you shouldn't disable NetBIOS for the Win2K clients.

It will take a little explanation as to what is going on and why. I have the time, so here we go:

Win2K has NetBIOS on by default. What that means is thatwhen you try and access a shared resource (shared printer, shared folder) on another machine from a Win2K client, the Win2K machine communicates on TCP port 139 & TCP port 445. Now, whichever port answers the ACK first is the one that Win2K uses forits File and Print Sharing communication.

139 is supported on all modern Windows machines (Win95 onward). 445 is new to Win2K (and XP); it is NOT used by Win 95/98/ME or NT4.

Now, as you can guess, when a Win2K client talks to a NT4 machine, the communication is gonna use TCP port 139, since that is all NT4 had. And that summarizes your problem. Since you have all these down-level clients (NT4 and the 98 box), if you disabled "NetBIOS Over TCP/IP" for Win2K, then your Win2K machines wouldNEVER be able to hit a shared folder on the NT4 machines or 98 machine. They could talk to themselves all they want (and the XP machines), but never the older ones.

So, until you are all Win2K/XP, you cannot remove NetBIOS.

Here is a nice article on port 445 and how it is replacing port 139:
http://ntsecurity.nu/papers/port445/

hope this helps

Bottom line is that any win2k pc that has NetBios over TCP/IP disabled will not be able to browse /communicate with a WINNT/Win98 PC.
I have tested it!! If your 2000 boxes have no need to communicate with your downlevel OS's (as microsoft likes to call them) then there is no problem. In my case a few users require a drive mapped to a 98 box, so they are unable to have netbios disabled at this time. I have manually disabled NetBios over TCP/IP on many other win2k boxes and have not had any problems at all. Good luck

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