Ask Dr. Bob Your NT Questions - 06 Jan 2000

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Some of our remote laptop users dial in to our company's RAS server to launch Microsoft Outlook 98. However, the Outlook client issues a Network connection is not available message. The laptop users can ping all machines on the network and browse them in Network Neighborhood, but they can't connect to Microsoft Exchange Server. Some users work around this problem by repeatedly clicking Retry, but this workaround is tedious. Should we be using a WINS server?

A WINS server might solve your problem, particularly if the Exchange Server is at least one router hop away from the RAS server (because a host on a network with out a name server can't use broadcasts to resolve the name of another host system). Be sure to put the WINS server address in both the primary and secondary WINS server address fields in the TCP/IP configuration properties dialog box on the RAS server. This procedure helps to ensure that the RAS clients inherit the proper WINS server addresses from the RAS server.

However, other potential solutions don't require WINS. For example, you can place on the RAS clients an entry for the Exchange server in the LMHOSTS or HOSTS file. (For best performance, I recommend using HOSTS.) However, this solution is more difficult to implement and manage than the WINS solution and incurs more administrative overhead. Alternatively, make sure that you've installed Service Pack 4 (SP4) or later on all involved Windows NT machines (i.e., RAS clients, RAS servers, and the Exchange server). I encounter more name-resolution problems on pre-SP4 NT machines than I do on machines with SP4 or later. If you've used LMHOSTS file entries in the past to resolve problems with RAS client name resolution, the name-resolution problems might return after you install SP4. If the problems return, rename or delete the LMHOSTS file on the client, then use NT's NetBIOS over TCP/IP (NetBT) Statistics (Nbtstat) utility to reload the NetBIOS name cache. Simply type

nbtstat ­RR

at the command line. Alternatively, you can restart the system.

Another potential cause of your problem isn't related to name resolution. The Network connection is not available error message might appear when users dial in to the Exchange server's network from a locally authenticated NT workstation (as opposed to a workstation authenticated on the domain housing the Exchange server). In this situation, you can access the Outlook profile and change the configuration of the Exchange Server service to work around the problem. In the Exchange Server service's Properties dialog box, select the Advanced tab and change Logon network to None. This procedure forces the client to authenticate explicitly to the Exchange server's domain before attempting to connect with the workstation's locally logged-on credentials.

I replaced my old dial-up Internet connection and ISP with a new Digital Subscriber Line (DSL) and ISP service. In the old scenario, I could use Microsoft Proxy Server 2.0 to access the Internet from my workstation. However, using my new DSL setup, I can't use Proxy Server to access the Internet from my workstation. DSL uses a NIC and a DSL bridge or router. (I use a bridge.) I have no free PCI slots, so I can't add another NIC to the server, and I don't want to use an ISA card. How can I use a proxy server or router to access the Internet from my workstation?

You can leverage your DSL connection for your server and internal workstations. Start by disabling Proxy Server's Autodial option, which your previous dial-on-demand configuration probably enabled. DSL is an always-on technology, so you don't need to use RAS to dial the connection. Next, you'll need to configure a second IP address (i.e., interface) on the Windows NT server for the DSL connection (i.e., the network segment that connects to the DSL bridge) to use. Although the best and most secure way to accomplish this configuration is to use a second NIC and assign it the IP address that your ISP gives you, I'll assume that you'll be using only one NIC.

Assign a second IP address to the NIC on your server. Then, make sure to connect the DSL bridge to the same hub as your server and workstation. In this configuration, you'll essentially run two separate logical IP subnets over one Ethernet segment. (For example, you might have a private or nonroutable address of for the connection to the private, internal network, and a routable IP address of for the connection to the DSL bridge.) After you verify that your Proxy Server configuration is correct and reboot the server, you can access the DSL Internet connection from your workstations through the proxy server.

I recently performed this procedure for one of my Microsoft Small Business Server (SBS) clients who had just converted from dial-up to DSL. However, I discovered a bug wherein the proxy server would continually offer its own Web page, rather than the intended Web site, to proxy clients attempting to browse the Internet. The solution to this problem was to upgrade the server to Service Pack 4 (SP4—a later service pack would also have worked.)

I have no problems when I mix ISA and PCI. However, I prefer to use PCI cards because they're easier to manage and tend to generate less of a load on the system CPU. If you can't free a PCI slot, you can replace your current NIC with a dual-port PCI NIC, such as those from Intel and Adaptec.

I need a small, fast, efficient application that calculates the size of users' home directories. In our network, these folders store a large amount of data, and I'd like to be able to analyze space usage and sort the directories (and subdirectories) by size. The limited feature set of the Microsoft Windows NT Server 4.0 Resource Kit's Diruse utility hasn't solved my problem. Any suggestions?

To perform disk-usage analysis, check out the DISKdata utility from Digital Information Gallery ( Screen 1 shows DISKdata in action. This handy utility provides a Windows Explorer-like GUI and analyzes disk-space utilization across various volumes and folders. DISKdata can display usage in report and chart format, and the available statistics include file and folder size, allocated size, storage efficiency, modification date, attributes, and version information.

Windows NT 4.0 provides powerful memory management but tends to use a large file-cache size. My system has 64MB of memory, and I want to use the physical memory more effectively for applications. Task Manager reports that physical memory consumes only 30MB and the file cache uses about 10MB to 18MB. How can I decrease my system's cache size?

NT's Virtual Memory Manager (VMM) dynamically allocates memory between the system cache (which NT uses for network and file caching) and the memory available to system processes, including applications. This allocation occurs on the fly, depending on which type of memory-usage load the system is experiencing. However, the following factors affect the formulas that NT uses to make these allocations:

  • The OS that you're using: NT Server or NT Workstation
  • The configuration of the Server service, which modifies Registry values that affect system cache size
  • The configuration of other services and Registry values that affect the system cache size

NT Server lets you tune memory allocation between processes and the system cache. To get to the dialog box that Screen 2, page 236, shows, go to the Control Panel Network applet's Services tab. Click Server, then click Properties. Your choices are as follows:

  • Minimize Memory Used—Minimizes memory use for the file cache.
  • Balance—Balances memory distribution between the cache and the running processes.
  • Maximize Throughput for File Sharing—Favors memory use for the system file cache.
  • Maximize Throughput for Network Applications—Favors memory use for applications.

These settings control how NT allocates memory between the system cache and the Server services, and thus affect the size of the cache. The default setting for NT Server is Maximize Throughput for File Sharing, which sets the LargeSystemCache Registry value in the HKEY_LOCAL_MACHINE\SYSTEM\ CurrentControlSet\Control\Session ManagerMemory Management subkey to 1.

NT Workstation doesn't provide the Properties option for the Server service. However, by default, NT Workstation uses the Minimize Memory Used option, which sets the value of LargeSystemCache to 0. If you're using an NT workstation, it's already configured to optimally allocate memory to applications and minimize system cache usage. However, you might want to inspect your workstation's Registry and verify that the LargeSystemCache value is 0 and not 1.

To further reduce the system cache size, try disabling the Server service on your system. Simply stop the Server service in Control Panel and set its startup type to Disabled. This procedure eliminates your ability to share files and use Named Pipes on the machine. However, if those items aren't important to you, try this configuration.

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