January 2000

Troubleshooting an Incomplete Network Neighborhood

by Gregory Shultz

If you have Windows 95 and Windows 98 workstations on a network that primarily access shared resources on a Windows NT server, you may encounter a situation where the Windows 9x systems won't display the entire list of shared resources in Network Neighborhood. When this type of a problem occurs, chances are that you'll assume there's a problem with the physical connections, the shares themselves, or any one of the variety connectivity problems and direct your troubleshooting efforts in that direction. However, we've recently discovered that this type of a problem is caused by differences in the way Windows NT and Windows 9x manage shared resources. In essence, the problem is caused by the fact that Windows NT's specifications far exceed Windows 9x's limitations. Knowing these limitations and understanding how they come into play can help you avoid hours of wasted time.

In this article, we'll take a look at the limitations that prevent Windows 9x from displaying a complete list of shared resources on a Windows NT server. As we do, we'll explain the problem in detail.

Understanding the problem

To begin, there are actually two different factors that can prevent Windows 9x systems from being able to display a complete list of shared resources on a Windows NT server. Furthermore, the overall problem can be compounded when both factors come into play in the same situation--making troubleshooting a real nightmare. The first factor in the problem is that Windows NT allows you to use more detailed comments to describe a shared resource than Windows 9x does. The second factor is that a Windows NT server can actually share more resources than a Windows 9x system can handle.

The length of the comments

When you create a share on a Windows NT server, you probably use the Comment text box to provide users with a detailed description of the shared resource. For example, Figure A shows a Comment text box for a shared folder containing a product upgrade.

Figure A: You can use the Comment text box to provide users with a detailed description of the shared resource.
Figure A

Since the Comment text box in Windows NT can hold a maximum of 256 characters of text, you probably don't even pay attention to the number of characters contained in your description.

However, the Comments text box in Windows 9x systems can only hold a maximum of 48 characters of text. This means that when a Windows 9x system is gathering a list of shared resources with long comments from a Windows NT server, it assumes that the Comments text box is 48 characters in length as it calculates the size of the buffer needed to list all of the shared resources.

The maximum size of the buffer that Windows 9x uses to store its list of shared resources is 64 KB or 65,536 bytes. Once the buffer is full, the Windows 9x system is unable to see anymore shared resources. Furthermore, it won't even recognize that there's a problem. As such, the Windows 9x system simply displays an incomplete list in Network Neighborhood.

Of course, the obvious solution to this problem is to limit the comments for each share on your Windows NT server to 48 characters. However, doing so may not entirely solve the problem. As we mentioned earlier, there may be a second factor compounding the problem.

The number of the shares

In addition to the total length of the comment fields exceeding the buffer, the sheer number of shares can also push the Windows 9x buffer beyond its capacity. However, unlike the comment field with its 48 character maximum, there isn't a specific value that demarcates the absolute number of shared resources that Windows 9x can display. Rather, the number of shares is limited by the size of the buffer.

Calculating the number

Fortunately, there's a formula you can use to calculate the maximum number of shares that a Windows 9x system can display. The formula is 

65,536 / (CommentLength + 21) = 
=>MaxNumberOfShares

For example, if you use 48 characters for the comment, you'll discover that the maximum number of shared resources that Windows 9x can display in Network Neighborhood is 949.

Copyright © 2000, ZD Inc. All rights reserved. ZD Journals and the ZD Journals logo are trademarks of ZD Inc. Reproduction in whole or in part in any form or medium without express written permission of ZD Inc. is prohibited. All other product names and logos are trademarks or registered trademarks of their respective owners.