Using DOS and Windows 3.1

     DOS and Windows 3.1 are the only operating systems covered in this chapter that do not have any built-in network clients. In order to connect a computer running these operating systems to a Windows 98 network, you must install a separate client program available from Microsoft.

     The Microsoft Network Client 3.0 for MS-DOS is available as a free download from Microsoft's FTP site at ftp://ftp.microsoft.com/bussys/Clients/MSCLIENT. The same client is also furnished with the Windows NT Server product, which has a program called the Network Client Administrator that creates installation and boot disks containing the client files.

     Like DOS itself, the client is not new technology, and you may in some cases have trouble finding drivers for the latest network interface cards. However, this client provides support for all of the standard networking protocols (NetBEUI, TCP/IP, and IPX/SPX) and enables you to access the drives and printers shared by other machines on the network.

     Warning: The Microsoft Network Client for MS-DOS is just that, a client, and does not provide any server functions. This means that while you can access shares on other computers, you cannot share the resources on the DOS machine with the rest of the network. This may be a major inconvenience for the administrator, as well as for users requiring access to the files stored on DOS systems.

     The other major drawback of using this client is the amount of conventional memory it requires. The DOS client runs in real mode, meaning that the system processor is emulating the old Intel 8088 and 8086 processors. Real mode drivers cannot access extended memory (the memory above the first megabyte in the computer) and therefore utilize the conventional memory needed by applications.

     A full installation of the client with all of its optional features can utilize as much as 360 K of conventional memory, sometimes reducing the amount of available memory to the point that you cannot run Windows 3.1 or other applications. Memory management is one of the fundamental problems of DOS, and is itself a good reason to upgrade to Windows 95.

     Tip: If you currently use DOS with Windows 3.1, you can evade the conventional memory requirements of the Microsoft Network Client for MS-DOS by upgrading to Windows for Workgroups, which uses protected mode (rather than real mode) drivers that load into extended memory. The functionality and graphical interface of Windows for Workgroups is virtually identical to that of Windows 3.1, except for additional networking features such as drive and printer sharing and the ability to access network resources through the File Manager application.

DOS Client Architecture

     The Microsoft Network Client for MS-DOS provides many of the same features as the Windows 98 client, in a package that runs on virtually any DOS PC. The following sections examine some of the client's components and how they function to provide networking functionality to DOS and Windows 3.1 applications.

Network adapter drivers

     Like all of the Microsoft network clients, the client for MS-DOS uses an NDIS (Network Device Interface Specification) driver for the network interface card installed in the computer and additional drivers for the protocols that you choose during the client installation. The NDIS driver in this case conforms to version 2.0 of the NDIS standard. NDIS 2.0 NIC drivers are 16-bit modules with a .dos file name extension, written in assembly language, that run in real (as opposed to protected) mode on the computer. This means that the drivers load before the Windows GUI and run in conventional memory.

     Other versions of Windows, such as Windows for Workgroups, Windows 95, and Windows 98, also include NDIS 2.0 drivers, but they are intended for use only when it is not possible to run the enhanced mode drivers included with those operating systems. For example, when you press the F8 key while booting a Windows 98 machine and select Safe Mode with Network Support, the system loads its real-mode NDIS 2.0 drivers to provide basic networking capabilities.

Redirectors

     The module that provides the basic network client functionality is the redirector, that functions in much the same way as the redirector in the Windows 98 Client for Microsoft Networks. This module determines whether a resource requested by an application is located on a local or network device and sends the request to the appropriate place.

     The client includes two redirectors: basic and full, that trade off performance for memory utilization. The basic redirector provides simple access to network drive and printer shares using any of the supported protocols. The redirector module itself only uses 10 K of memory, and will run on any PC with an 8088 processor or better. The full redirector is faster and provides additional functions, such as domain logons, and is required if you will be running Windows 3.1 or RAS with the client. The full redirector requires 88 K of memory and an 80286 processor or better. The client uses the full redirector by default, but if you will be running DOS only, you can save a great deal of memory by installing the basic redirector instead.

     Note: The memory requirements of 10 K and 88 K for the basic and full redirectors (respectively) refer only to the memory required by the redirector itself. The protocol drivers for the client have their own memory requirements.

Protocols

     The client also includes drivers for the three standard networking protocols that Microsoft systems use at the network transport layer. Just like on a Windows 98 system, you can elect whether to use NetBEUI, TCP/IP, or IPX for your basic networking tasks, plus Microsoft DLC for network printing. The decision regarding which protocol(s) to use is a more strategic one on MS-DOS systems than on Windows 98, because you must balance the functionality you require with the limited amount of conventional memory available on the machine and the more rudimentary memory management capabilities of the DOS operating system.

     As with Windows 98, NetBEUI is a good choice for a small network, with the added benefit in DOS that it requires a much smaller memory footprint than TCP/IP. However, if you want to access the Internet or intranet services from a DOS machine running Windows 3.1, you will have to use TCP/IP. The Microsoft Client for MS-DOS does not support connectivity to NetWare networks, so the choice of Nwlink, Microsoft's version of the IPX protocol, is impractical here.

Network browsing

     The Microsoft Client for MS-DOS cannot function as a master browser on the network. The master browser is a computer that is responsible for maintaining the list of other computers and shares on the network. Other systems use this list to browse through the available resources on the network using applications like the Network Neighborhood in Windows 98 Explorer, File Manager in Windows for Workgroups, and the pop-up interface in the DOS client.

     One computer on the network is designated as the master browser as a result of an election between all of the computers capable of functioning as a browser. Since the client for DOS cannot function as a browser, it cannot be elected as master browser. In order to be able to browse the network using the DOS client, there must be a computer running Windows for Workgroups, Windows NT, Windows 95, or Windows 98 on the network to function as the master browser.

     If you have a network that consists only of computers running the Microsoft Client for MS-DOS, then none of the systems will be able to browse the network. However, the ability to browse the network is separate from the ability to connect to network shares. Even if there is no master browser, it is still possible to connect to a share by specifying its UNC name in the normal manner.

Pop-up Interface

     The Microsoft Client for MS-DOS includes an optional pop-up interface that you can use to browse among the shares on the network and map shares to drive letters. To load the interface, you must select Run Network Client and Load Pop-up on the client installation program's Setup Options screen. You can then activate the interface by pressing the Ctrl+Alt+N key combination (by default), which displays a screen like that shown in Figure 8-1. You can select a different letter for the key combination during the client installation process.



Figure 8-1: The client's pop-up interface provides a simplifies means for managing connections to network shares.

     The pop-up interface provides a relatively intuitive mechanism for mapping drive letters that is simpler than the NET USE command at the DOS prompt and enables you to map drives without shelling out of an application, but the cost is high. The interface consumes 34 K of memory, 26 K of conventional and 8 K of upper memory (if available). Given the amount of memory consumed by the other client components, the pop-up interface is usually not worth loading at boot time, since the same interface appears when you use the NET command at the DOS prompt. You can also load the pop-up interface into memory at will and unload it afterwards using the NET START POPUP and NET STOP POPUP commands.

     On a small network, you would be better off creating persistent connections to all of the other shares the user will need, so that they do not have to create any additional drive mappings of their own.

Memory requirements

     Depending on which of the DOS client’s features you choose to load, the amount of memory it consumes can range from a total of 66,672 bytes to as much as 371,824 bytes! At its largest, the client leaves very little memory for applications to use. In fact, the client setup program itself requires 429 K, and would not run with a full installation loaded into conventional memory. Fortunately, there are many modules that can use upper memory for some or all of their code, and with proper memory management techniques, you can lessen the burden of the client on your systems.

     Tip: as mentioned earlier, the most prudent action if you’re currently running DOS with Windows 3.1 is to abandon the Client for MS-DOS entirely and upgrade your systems at least to Windows for Workgroups, if not to Windows 98. Windows for Workgroups presents users with the same graphical interface as Windows 3.1, but uses enhanced mode network drivers that do not require excessive amounts of conventional memory to run.

     Even with judicious use of upper memory, however, your will probably have to limit the client features you choose to install, in order to save on conventional memory. The 371,824 byte figure mentioned earlier is for a complete client installation that includes all three network transport protocols (NetBEUI, TCP/IP, and IPX), as well as the pop-up interface and the modules required to run Windows Sockets applications, such as web browsers. The following listing is an excerpt from the DOS MEM command output for a system with the complete client loaded, showing only the modules installed by the DOS client and the memory they consume:


  Name     Total =   Conventional   +   Upper Memory
  -------- ----------------   ----------------   ----------------
  IFSHLP   3,968    (4K)3,968    (4K)    0    (0K)
  PROTMAN  2,560    (3K)2,560    (3K)    0    (0K)
  ELNK3    9,328    (9K)    0    (0K)9,328    (9K)
  NDISHLP  1,440    (1K)    0    (0K)1,440    (1K)
  PROTMAN  400      (0K)    0    (0K)  400    (0K)
  REDIR    118,224  (115K)    114,416  (112K)3,808    (4K)
  NETPOP   34,832   (34K)     26,144   (26K)8,688    (8K)
  NETBEUI  37,776   (37K)     37,104   (36K)  672    (1K)
  NWLINK   10,144   (10K)     10,144   (10K)    0    (0K)
  TCPTSR   77,056   (75K)  272    (0K)     76,784   (75K)
  TINYRFC  18,224   (18K)     18,224   (18K)    0    (0K)
  NMTSR    6,160    (6K)  6,160    (6K)    0    (0K)
  UMB960            (1K)  272    (0K)  688    (1K)
  NEMM     672      (1K)    0    (0K)  672    (1K)
  TCPDRV   1,328    (1K)    0    (0K)1,328    (1K)
  DNR      14,512   (14K)     14,512   (14K)    0    (0K)
  SOCKETS  34,240   (33K)     34,240   (33K)    0    (0K)
     The first group of modules in the listing includes the IFS manager (IFSHLP, which passes data to the proper device depending on whether the requested resource is local or remote), the protocol manager (PROTMAN, which binds the protocol drivers to the NDIS network adapter driver), the network adapter driver (ELNK3), and other components that are required for every client installation. Notice that much of the code for these modules can load into upper memory, thus conserving conventional memory for applications.

     The REDIR module is the full redirector, which in this case includes the additional network buffers. This is by far the largest single module, in terms of conventional memory consumption, but you can reduce its size considerably by omitting the extra network buffers (as described in "Setting network buffers," later in this chapter), or by installing the basic redirector instead of the full one.

     If you are running Windows 3.1, you must use the full redirector, but you can still save the 10 to 20 K devoted to the extra network buffers. If you plan to run DOS only, the basic redirector (which shows up in the MEM listing as BASIC) requires only about 13 K, which is obviously a dramatic improvement.

     The NETPOP module is the pop-up interface. Omitting this is the easiest way to save 34 K.

     Another way to reduce the memory requirements is to install only the protocols that you absolutely require. This listing includes all three, when usually one will be sufficient. NetBEUI and IPX (provided by the NWLINK module) both require only a single module, while the entire group of eight modules totaling 153,152 K at the end of the listing is devoted to TCP/IP.

     While TCP/IP requires the most memory of the three protocols, it is possible to reduce its memory requirement. The DNR and SOCKETS modules are required only when you will be running Windows Sockets applications, like web browsers, in Windows 3.1. If you plan to use TCP/IP only for communications with other computers on the local network, you can eliminate these modules by removing the lines from Autoexec.bat that load Dnr.exe and Sockets.exe, thus saving 47 K.

Installing the Microsoft Client for MS-DOS

     Because it runs using only the most basic system resources, you can install and run the Microsoft Client for MS-DOS on virtually any PC. The minimum system requirements for the software are as follows:

     You can use the client to make network resources available to Windows 3.1, but you should not use the client for MS-DOS with other versions of Windows, such as Windows for Workgroups, Windows 95, or Windows 98.

     The client includes an interactive installation program called Setup.exe that enables you to select and configure the features you want to install. The program then copies the appropriate files to the directory of your choice (C:\Net, by default), modifies the configuration files for the client (Protocol.ini and System.ini), and adds the appropriate commands to the system's Config.sys and Autoexec.bat files to load the client when the system boots.

     Note: The client's Setup.exe program requires 429 K of conventional memory to run. You may have to use the Memmaker utility in MS-DOS 6.x or manually adjust the commands in your Config.sys and Autoexec.bat files to free up this much RAM.

Network adapter detection

     If the Microsoft client includes a driver for the network card installed in the computer, it may detect it automatically, or present you with a list of supported NICs from which you can choose (see Figure 8-2). If your card is not supported by the drivers shipping with the client, you can usually obtain an NDIS 2.0 driver from the manufacturer’s web site or other online service. An NDIS 2.0 driver package typically consists of the driver itself, which has a .dos extension, a .nif file, which provides recommended settings for the client configuration files, and an Oemsetup.inf file, which the setup program uses to locate the driver file and identify the possible values for the hardware resource settings.



Figure 8-2: The Microsoft Client for MS-DOS NIC driver listing.

     Tip: Microsoft Client for MS-DOS includes drivers for over 100 network interface cards, but since the client is over five years old, there are many new cards that it doesn't support. If your specific network interface card is not listed, it is worth trying the NE2000 Compatible driver, which works with many different NICs.

     To use a driver package obtained from another source, select Network Adapter Not Shown On List Below and specify the path to the driver files in the screen provided.

     Just like the later version NDIS drivers used in Windows 98, NDIS 2.0 drivers must use the same hardware resources as the network interface card installed in the computer. If the installation program successfully identifies the NIC, then it will usually configure the hardware parameters automatically as well. If it does not, then you will have the opportunity to modify the hardware parameters later in the installation.

     Tip: If the client's setup program fails to run properly or hangs up while trying to identify the network interface card, you can run Setup.exe with the /I parameter, which disables the entire hardware detection process. You will then have to select the NIC driver you want to install and the values for the hardware resource parameters.

Setting network buffers

     After Setup.exe identifies the network interface card, the program prompts you to specify whether or not it should install using more memory for network buffers in order to improve performance. This is one feature that might want to enable when you first install the client, but keep it in mind if you find yourself in a situation where you must minimize the amount of conventional memory that the client uses. Later, you may want to trade off performance in order to have enough free conventional memory to be able to run all of your programs. The difference on an installation of the full redirector when you opt to set up the client without optimizing performance is a reduction of 10 to 20 K in the conventional memory used by the redirector module, which is shifted to upper memory instead.

Selecting a user name

     When the client prompts you to specify a user name, you must supply a name consisting of up to 20 characters, alphabetical, numeric, or any of the following symbols:

! # $ % ^ & ( ) ` { } ~ _

     When the setup program creates the configuration files for the client, it uses the name you specify here both as the logon name for the user and the NetBIOS name for the computer. You will have the opportunity to change both later in the installation.

Setting up the MS-DOS client

     The main setup screen shown in Figure 8-3 is where you configure all of the client's optional features and operational parameters. This screen also displays the current values of the client's basic configuration options. As with all of the screens in the setup program's interface, you make selections by using the cursor keys to highlight an option and press the Enter key to select it.



Figure 8-3: The Microsoft Client for MS-DOS uses a menu-driven interface to install and configure the software.

The Change Names screen

     When you select Change Names from the main setup screen, you can specify values for the following options:

     Change User Name

     Specifies the default name that the client will use when logging on to the network. The default value is the name you supplied earlier in the installation. During the logon, you can accept the name you furnished previously or specify a different one.

     Change Computer Name

     Specifies the NetBIOS name that will identify the computer to the rest of the network. By default, the setup program uses the same user name supplied earlier in the installation. In most cases, it is better to give computers names that are independent of their users, so that you don't have to change them when a person changes jobs or leaves the company.

     Change Workgroup Name

     Specifies the name of the workgroup that the computer will join when logging on to the network. The workgroup name you supply should already exist on your network.

     Change Domain Name

     Specifies the name of a Windows NT domain that the computer will join when logging on to the network. For a small peer-to-peer network, this parameter is not needed.

The Change Setup Options screen

     On the Change Setup Options screen (see Figure 8-4), you specify the basic options for the client installation. These options largely determine the amount of memory that the client will require and functions it will provide.



Figure 8-4: The Change Setup Options screen enables you to select the functions provided by the client.

The available options are as follows:

Change Redir Options

Specifies whether you want to install the basic or full redirector. The default is to install the full redirector.

Change Startup Options

Specifies how the setup program should configure the client to load when the system starts, using the following options:

Change Logon Validation

Specifies whether or not the client should log on to the domain specified in the Change Names screen. The default is not to log on to the domain.

Change Net Pop Hot Key

Specifies the key that will activate the pop-up interface when pressed with the Ctrl and Alt keys. The default value is N.

The Change Network Configuration screen

     The Change Network Configuration screen (shown in Figure 8-5) is where you select and configure the protocols to be installed by the setup program and modify the hardware configuration parameters for the network adapter driver. The screen contains two boxes, one listing the currently installed network adapters and protocols, and the other listing the functions you can perform.



Figure 8-5: The Change Network Configuration screen contains the network adapter and protocol configuration options.

     The basic functions of this screen are to add modules to or remove them from the list of installed adapters and protocols and to configure the installed modules. The driver for the adapter that the setup program detected earlier should already be present in the top box. You can select the protocols to install or delete by using the cursor keys to highlight Add Protocol or Remove in the Options box and pressing Enter to select it.

     To work with a particular module in the list of installed adapters and protocols, you press the Tab key to shift the focus to the top box and select the desired module with the cursor keys. After tabbing back to the Options box, you can select a function to be performed on the highlighted module.

     The Change Settings function displays a customized configuration screen for the selected module. When you highlight the installed network adapter and proceed to change its settings, you see a screen listing the hardware resources required by that card. By selecting one of the parameters and pressing Enter, you display a list of the possible values for that parameter from which you can choose.

     The settings for the NetBEUI protocol are the same as those is Windows 98. The Maximum Sessions parameter has a default value of 10 and the NCBS parameter has a default value of 12. For more information, see "Configuring NetBEUI settings" in Chapter 6, Installing Network Hardware.

     The TCP/IP protocol is the only one of the protocol modules that requires configuration before use on a peer-to-peer network. The Microsoft Client for MS-DOS supports automatic TCP/IP configuration via a DHCP server, but since this requires a Windows NT server on the network, you will have to configure the protocol manually.

     When you highlight the TCP/IP protocol module and select Change Settings, you see the screen shown in Figure 8-6, which contains the following parameters:



Figure 8-6: Unless you have a DHCP server on your network, you must configure the TCP/IP settings before the protocol will function.

     Disable Automatic Configuration

     Specifies whether or not the client should request TCP/IP configuration settings from a DHCP server on the network. The default value is 0, which enables the DHCP client. On a peer-to-peer network, you should change the value to 1, which disables the DHCP client and enables you to specify values for the configuration settings manually.

     IP Address

     Specifies the unique IP address to be assigned to the network interface card in the computer. Since the Protocol.ini file, where these settings are stored, uses only integers, the four decimal values (called octets) that comprise the address must be separated by spaces and not periods as in standard IP address notation.

     IP Subnet Mask

     Specifies the mask used to separate the network bits in the IP address from the host bits, using four octets separated by spaces.

     Default Gateway 0

     Specifies the IP address of the system that serves as the gateway to other networks, using four octets separated by spaces. On a small peer-to-peer network, you only have to supply a value for this option if you are connecting to the Internet through a shared connection on another machine.

     Default Gateway 1

     Specifies the IP address of an alternate gateway to other networks, should Default Gateway 0 fail, using four octets separated by spaces.

     NetBIOS Sessions

     Specifies the maximum number of NetBIOS sessions the client can have open at any one time. The possible values range from 1 to 12, and the default value is 6.

     Tip: See "Configuring TCP/IP Settings" in Chapter 6, Installing Network Hardware, for more information on selecting IP addresses and values for the other configuration settings.

Completing the installation

     Once you have configured the options you want to install, select The Listed Options are Correct and the program will proceed to copy the required files and modify the configuration files, including your Config.sys and Autoexec.bat. When you reboot the system, the client will load, log on using the name you supplied earlier, and prompt you for a password. Once you're logged on you can connect to network resources using the NET command or load Windows 3.1.

Changing Options

     If you want to modify the client configuration after the installation is complete, you can run the Setup.exe program from the directory in which you installed the client (typically C:\Net). The program functions just as it did during the installation, enabling you to modify any of the parameters accessible from the main setup screen.

     If for any reason (such as a shortage of conventional memory) you cannot run the setup program, you can also make manual changes to the client's configuration files. These files use the same names as Windows configuration files and have the same basic structure, but they are stored in the C:\Net directory and should not be confused with the identically-named files used by Windows.

System.ini parameters

     The System.ini file in the C:\Net directory (by default) stores many of the parameters that you configured when you installed the client. You can modify your settings at any time by changing them in this file and rebooting the system to put your changes into effect. The following directives are all located under the [Network] heading of the file and consist of a parameter and a value, separated by an equals sign ("=").

     Tip: The same basic System.ini file is used by other early clients for LAN Manager and other products, which explains why some of the directives included in the default file have no effect on the Microsoft Client for MS-DOS.

     filesharing

     Not used by the Microsoft Client for MS-DOS, as the software does not support the sharing of files on the client system. The default value is no.

     printsharing

     Not used by the Microsoft Client for MS-DOS, as the software does not support the sharing of printers on the client system. The default value is no.

     autologon

     Specifies whether or not the system should automatically log on to the network during the boot process. The default value is yes.

     computername

     Specifies a unique NetBIOS name for the computer that will identify it to the other systems on the network. The default is the value you specified during the client installation.

     lanroot

     Specifies the name of the directory in which you installed the client. The default value is C:\Net.

     username

     Specifies the default name that the client will use when logging on to the network. The default is the value you specified during the client installation, but you can supply a different name during the logon.

     workgroup

     Specifies the name of the workgroup that the computer will join when logging on. The default is the value you specified during the client installation.

     reconnect

     Specifies whether or not the client should reconnect to the shares that you mapped to drive letters during the previous session. The default value is yes.

     dospophotkey

     Specifies the key that activates the pop-up interface, when you press it with the Ctrl and Alt keys. The default value is N.

     lmlogon

     Indicates whether or not the client should log on to the Windows NT domain specified by the logondomain directive. The default value is 0, meaning that the client should not log on to the domain. To activate the domain logon, change the value to 1.

     logondomain

     Specifies the name of the domain that the client will log on to, if the value for the lmlogon directive is 1. The default is the value you specified during the client installation.

     preferredredir

     Specifies whether the client should load the basic redirector or the full redirector when executing the NET START command. The possible values are basic and full; the default is the value you specified during the client installation.

     autostart

     Specifies whether the client should load the client during system startup and whether the pop-up interface should load. The value is taken from the redirector and the startup option that you chose during the client installation. Possible values are basic or full, with POPUP optionally added after a comma (e.g.: autostart=full,popup). If you selected Do Not Run Network Client as the startup option, the value for this directive is left blank, but the NET START command is still added to the Autoexec.bat file.

     maxconnections

     Not used by the Microsoft Client for MS-DOS. The default value is 8.

     sizworkbuf

     Specifies the size of the work buffers that the client uses during SMB (server message block) communications with other systems on the network. The default value is 1498 when you elect to optimize performance with extra network buffers during the client installation, as discussed in "Setting network buffers," earlier in this chapter. If you choose not to install the extra buffers, this entire directive is omitted.

Protocol.ini parameters

     The Protocol.ini file contains the configuration parameters for the individual protocols, some of which you can modify directly. The [TCPIP] section of the file, as shown in the following excerpt, contains the directives corresponding to the settings you configured during the client installation (see "The Change Network Configuration screen," earlier in this chapter). You can modify them at will, and your changes will take effect when you next reboot the system.

[TCPIP]

     NBSessions=6

     DefaultGateway0=192 168 2 100

     SubNetMask0=255 255 255 0

     IPAddress0=192 168 2 2

     DisableDHCP=1

     DriverName=TCPIP$

     BINDINGS=MS$ELNK3

     LANABASE=0

     In the same way, the [MS$NETBEUI] section contains the directives for the Maximum Sessions and NCBS parameters. For general networking tasks, you should usually not have to modify the values for these parameters.

[MS$NETBEUI]

     DriverName=netbeui$

     SESSIONS=10

     NCBS=12

     BINDINGS=MS$ELNK3

     LANABASE=1

Windows 3.1 and the Microsoft Client for MS-DOS

     The Microsoft Client for MS-DOS provides access to the network both for DOS applications and for Windows 3.1. Although Windows 3.1 does not contain a network client of its own, it does have modules that enable applications like File Manager to make use of a real mode client installed and loaded before you launch Windows.

Installing Windows 3.1 Networking Support

     To install Windows 3.1's networking support, you launch the Windows Setup application in the Main program group and select Change System Settings from the Options menu. This displays the Change System Settings dialog box shown in Figure 8-7. In the Network field, select Microsoft Network (or 100% compatible) and supply the location of the Windows 3.1 distribution files when the program requests them.



Figure 8-7: Windows 3.1's networking support provides access to the function of the DOS client with the GUI.

     Once you restart Windows with this change in effect, the File Manager application contains a Network Connections command in the Disk menu that provides GUI access to the drive mapping functions provided by the NET command at the DOS prompt.

Installing Windows Sockets Support

     Although it is not obvious from the installation process, the Microsoft Client for MS-DOS does have the capability to resolve DNS names and to support Windows Sockets (Winsock) applications like web browsers in Windows 3.1. Unfortunately, the setup program does not properly configure the client to do these things, so you must modify the configuration files manually. Use the following procedure to enable Windows Sockets support and load the Domain Name Resolver (DNR):

  1. Expand the compressed Wsahdapp.ex_ file supplied with the client distribution files and copy it to the C:\Net directory (or to whichever directory you chose when installing the client. To expand the file, you use the Expand.exe utility included with both DOS and Windows 3.1, using the following syntax: Expand Wsahdapp.ex_ Wsahdapp.exe

  2. Edit the Autoexec.bat file and add two lines loading the Dnr.exe and Sockets.exe programs from the C:\Net directory, just before the NET START command. The part of the file that loads the client components should appear as follows: C:\NET\netbind.com

         C:\NET\umb.com

         C:\NET\tcptsr.exe

         C:\NET\tinyrfc.exe

         C:\NET\nmtsr.exe

         C:\NET\emsbfr.exe

         c:\NET\dnr.exe

         c:\NET\sockets.exe

         C:\NET\net start

  3. Edit the Tcputils.ini file in the C:\Net directory and add a new section that appears as follows, with the nameserver0 and nameserver1 directives specifying the IP addresses of DNS servers (supplied by your ISP). [dnr]

         drivername=DNR$

         bindings=TCPIP

         nameserver0=192 168 100 3

         nameserver1=192 168 100 4

  4. In the [tcpglobal] section of Tcputils.ini, add the directive hostname=name, where name is the computer name or any other logical name for the system.
  5. Modify the bindings=TCPIP_XIF directives in the Tcputils.ini file to read bindings=TCP, so that it references the correct section in the Protocol.ini file. The modified Tcputils.ini file should appear as follows: [tcpglobal]

    drivername=GLOBAL$

    hostname=cz2

    [sockets]

    drivername=SOCKETS$

    bindings=TCPIP

    numsockets=4

    numthreads=32

    poolsize=3200

    maxsendsize=1024

    [telnet]

    drivername=TELNET$

    bindings=TCPIP

    nsessions=0

    max_out_sends=0

    [dnr]

    drivername=DNR$

    bindings=TCPIP

    nameserver0=192 168 100 3

    nameserver1=192 168 100 4

     Once you restart the system, you should be able to run a web browser or other Internet application in Windows 3.1 normally.

Using the Microsoft Client for MS-DOS

     Once the Microsoft Client for MS-DOS is installed and loaded, you can use it to map drive letters to network shares. From the DOS prompt, you do this with the NET command. In Windows 3.1, any drives that you have already mapped are available to all of your applications, and you can map additional drives using the Network Connections dialog box in File Manager.

Using the NET Command

     Net.exe is a very powerful command-line utility that you can use to view and manipulate network resources in many different ways. All of the other Microsoft network operating systems, including Windows for Workgroups, Windows NT, Windows 95, and Windows 98, include the program and use the same syntax.

     NET

     Displays the pop-up interface, enabling you to browse the network shares and map drives.

     NET CONFIG

     Displays information about your network connection, including the computer name, the name of the user logged on, and the workgroup name.

     NET DIAG

     Uses the Microsoft Network Diagnostics program to test the connection between two network computers. When you run the NET DIAG command, the system searches for a diagnostic server on the network. If no diagnostic server is found, the system begins functioning as a diagnostic server itself, until you press a key to terminate the program. When the system detects a diagnostic server, the two machines connect and exchange test messages to determine if the network is functioning correctly.

     NET HELP

     Displays a summary of Net.exe's functions. To see more detailed information about a specific command, use NET HELP command or NET command /?., where command is a valid NET command. For information about an error message, use NET HELP error, where error is a valid error message number.

     NET INIT

     Loads the client's network adapter and protocol drivers without binding them to the protocol manager. The client installation program adds this command to the computer's Config.sys file.

     NET LOGOFF

     Closes all connections with network shares and logs the user off of the workgroup. To reconnect to the network, you must use the NET LOGON command.

     NET LOGON

     Logs the system onto the network and re-establishes all persistent connections to network shares. When you issue the NET LOGON command with no additional parameters, the program logs you on using the default user name you furnished during the client installation and prompts you for a password. You can also specify a user name and password on the command line using the following syntax:

     NET LOGON username password

     By default, the program will ask you if you want to create a password file for the user if one does not already exist. The client uses the password file (which is named using the first eight characters of the user name plus a .pwl extension) to store the passwords for the shares you connect to in encrypted form. To skip the prompt for the creation of the password file, add the /SAVEPW:NO parameter to the NET LOGON command line.

     NET PASSWORD

     Changes the password for a domain user logon.

     NET PRINT

     Displays information about print queues and enables you to manipulate your queued print jobs. To display the contents of a print queue, use any of the following commands:

     NET PRINT \\computer

     NET PRINT \\computer\printer

     NET PRINT port

     where computer is the NetBIOS name of a system functioning as a print server, printer is the name of a printer share, and port is the name of a printer port on the system that is connected to a network printer. To manipulate a queued job, use the following syntax:

     NET PRINT \\computer\printer job [/DELETE] [/PAUSE] [/RESUME]

     where job is the number of the job as listed in the queue display.

     Note: The NET PRINT command is used only to view and manipulate print queues. To connect a printer port to a queue, you use the NET USE command.

     NET START

     Loads client services into memory. With no parameters, the command loads the default redirector you specified during the client installation process. You can also load specific services from the command line using the following commands:

     NET START BASIC

     Loads the basic redirector.

     NET START FULL

     Loads the full redirector.

     NET START WORKSTATION

     Loads the default redirector specified during the client installation.

     NET START POPUP

     Loads the pop-up interface into memory.

     NET START NETBIND

     Binds the network adapter and protocol drivers to the protocol manager.

     NET START NETBEUI

     Loads the NetBIOS interface.

     NET STOP

     Unloads client services from memory, using the following command line parameters: BASIC, FULL, WORKSTATION, POPUP, NETBEUI.

     Note: You cannot start and stop services with the NET START and NET STOP commands from a Windows 3.1 DOS session. You must exit Windows entirely to use perform these actions.

     NET TIME

     Displays the time on another network system or synchronizes the computer's time with a time server on the network.

     NET USE

     Connects or disconnects the client system from shared network resources and manages persistent connections. To map a drive letter to a network share, use the following syntax:

     NET USE drive: \\computer\share [password]

     where drive is the drive letter you want to map (or an asterisk, which causes the program to use the next available drive letter after C:), computer and share identify a shared drive on the network, and password is the password needed to access the shared drive.

     To connect to a network printer, you use the same syntax with name of a local port (such as LPT1) instead of a drive letter, and the name of a printer share instead of a drive share. This causes all print jobs sent to the specified port to be redirected to the printer share on the network.

     In either command, you can add the \SAVEPW:NO parameter to prevent the client from saving the password for the share in the password file on the local system. This option is useful for administrators who have to access a special resource from a client system without compromising its security.

     To disconnect a drive letter or port from a share, you specify either the share name, the drive, or the port in the NET USE command with the \DELETE parameters, as in the following examples:

     NET USE f: \DELETE

     NET USE \\cz1\cdrive \DELETE

     NET USE lpt1 /DELETE

     To manage persistent connections, you use the /PERSISTENT parameter with one of the following options:

     NET USE /PERSISTENT:YES

     Causes all subsequent connections you establish to be persistent.

     NET USE /PERSISTENT:NO

     Causes all subsequent connections you establish to not be persistent.

     NET USE /PERSISTENT:LIST

     Lists the current persistent connections.

     NET USE /PERSISTENT:SAVE

     Changes all currently active connections to persistent connections.

     NET USE /PERSISTENT:CLEAR

     Clears all of the current persistent connections.

     You can also use the /PERSISTENT parameter in a NET USE command with the YES or NO option when connecting to a network drive or printer. This causes the connection being established to be made persistent or non-persistent, as well as setting the default for all subsequent connections.

     NET VER

     Displays the type of redirector currently loaded and its version number.

     NET VIEW

     Displays the shares on a specific computer or the computers in a specific workgroup, using the following syntax:

     NET VIEW \\computer

     NET VIEW /WORKGROUP:workgroupname

Using the graphical interfaces

     The DOS client's pop-up interface and the Network Connections dialog box in Windows 3.1's File Manager (shown in Figure 8-8) are different in appearance, but provide essentially the same functionality. Both enable you to connect drive letters to network shares by either browsing the network or manually entering UNC names. In the pop-up screen, you use the Tab key to move around the screen or press the Alt key with the highlighted letter in one of the various fields to move the emphasis there.



Figure 8-8: Although different graphically, the DOS client’s pop-up interface and the Windows 3.1 Network Connections dialog box operate in much the same way.

     After specifying a drive letter and entering or browsing for a share name, you use the connect command to map the drive, checking the Reconnect at Startup box (using the spacebar) to create a persistent connection. The Network Connections dialog box in Windows 3.1 functions in much the same way, but with the added convenience of the mouse, which is not supported in the DOS interface.

     To connect printer ports to shared printers, you press the Alt+S key combination in the pop-up interface, which modifies the display to show ports instead of drives. The Show Queue control displays the current print jobs waiting for processing in the selected queue, and enables you to pause, resume, and delete your jobs, just as you can with the NET PRINT command. In Windows 3.1, the printer management tools are found in the Print Manager application, which has a Network Connections dialog box that is also similar to its drive-sharing counterpart.

     The DOS and Windows client tools share the same underlying infrastructure, so that you can use them interchangeably with causing a conflict. If, for example, you connect drives and printer ports to network shares in DOS, you will find that the Windows tools show the previously established connections as well. If, however, you map a drive in a Windows 3.1 DOS session, you will find that if File Manager is already running, it will not show the drive as being mapped. Once you close the application and restart it, however, File Manager will display the proper connections.

     As mentioned earlier in this chapter, persistent connections are your best tool when it comes to introducing networking services to DOS and Windows 3.1 users. Rather than train them how to connect drives and printers on their own, you are better off doing it yourself and seeing to it that the system re-establishes the connections during every reboot. Since you will be working with a relatively small number of systems on your network, you should not have a huge number of shares to deal with. You should therefore be able to connect each computer to all of the shares they need without running out of drive letters.