UNIX and NT Integration with SCO Advanced File and Print Server

Using AFPS
If the PC users require logon access to the UNIX machine to run character-based applications, you must install TCP/IP and Telnet on your client systems. Microsoft provides Telnet in TCP/
IP, but only a limited version. With AFPS 3.5.2, SCO provides TermLite, a program that supports Telnet and vtp, a virtual terminal emulator that runs over NetBEUI and TCP NetBIOS. These tools provide SCO ANSI (console) emulation and work very well. Double-click the Network Neighborhood icon. You'll see the SCO UNIX server.

SCO provides a command line interface for the net command. For details on the net command, enter net from the root prompt (usually a #) on a non-GUI screen. For help on a net command, the syntax is similar to DOS. Simply type

net ?

or

net access ?

The net command encompasses a series of options including access, accounts, admin, auditing, config, continue, device, file, group, help, helpmsg, localgroup, logoff, logon, password, pause, perms, print, send, session, share, start, statistics, status, stop, time, trust, user, version, and view. You can pipe the output of these commands into a pager such as the more command or the UNIX pg command. Pagers let you send data on the screen one screen page at a time. The pg command allows movement up and down within the document displayed on the screen. If you have a PC on the network at this point, try running net view on the SCO system to see whether the PC is visible to the SCO machine. Remember, the PC must have file or print sharing enabled.

Now you can create shares from the command line with the net share command. The syntax is not intuitive to either the NT or UNIX guru. To create shares, the syntax is

net share sharename=devicename

To share directory /u/gene on the UNIX machine as a share named gh, enter the command

net share gh=c:/u/gene

UNIX people will shake their heads at the c:, and DOS people can't figure the / instead of \. This requirement is the sort of cross-operating-system problem you can run into in heterogeneous systems. UNIX uses the / character as the separator for directory path names, and NT uses the \.

You can use the SCO GUI to view shares, create new shares, or stop shares. From the GUI, double-click System Administration, double-click the filesystems folder, and double-click the Filesystem Manager icon. When the Filesystem Manager window appears, it will list the files (directories) shared through AFPS or through NFS. If the window displays Export status of filesystems on <machine name>, you are looking at an NFS display. To get the AFPS share status, click View, Export Status, View Advanced Server Shares, and OK. The window will display Advanced Server share status of filesystems on <machine name>. The directory names, share names, and comments are displayed in a scroll box. To share a directory, click Export, Advanced Server, and Share. Enter the directory name (or click Select to search for a directory), share name, and an optional comment, and click OK.

To stop sharing a directory, highlight a shared directory and click Export, Advanced Server, and Stop Sharing. A pop-up window will ask for confirmation: Stop sharing <directory>. Are you sure? Click OK. (The confirmation message is unusual for UNIX, which is not known for "Are you sure" messages.)

Defining Users
The next step is to set up users. You can set up UNIX users, Windows network users, or users with access to both a UNIX login and Windows networking. All three options are appropriate for certain users. Dumb terminal users are not networked and therefore cannot use Windows networking. Windows users whose work is confined to word processing and spreadsheets on their local PCs might need file and print sharing but no UNIX login. Users with PCs who do both UNIX work and Windows work need both.

In the scenario we started with, the client has UNIX users established on the UNIX system. The only step necessary to put these users on the network is to change one piece of their SCO UNIX login account (SCO's AFPS is integrated into the Administration GUI).

Let's grant a user access to Windows networking. From the SCO GUI, double-click the System Administration folder and then the Account Manager folder. To select an account, double-click it. Notice that the account has a blank entry for Networked Via. Click Change Distribution, which is to the right of the Networked Via blank entry. A pop-up window will appear with Local Only selected. Click the black button to the left of Local Only to deselect it, and Advanced Server will appear (already highlighted) in the box labeled Select Network Distribution Methods. Click OK. Click OK in the User box. If you installed the SCO box as the BDC, the account change will be synchronized with the PDC and the account will now appear in User Manager for Domains. Look at the account from User Manager for Domains to see that the account is disabled, has no full name or description, and is a member of the Domain Users group. You must enable the account and enter a password to make it usable for Windows networking.

To create a new user with access to both UNIX and Windows networking, select Users, Add New User, from the Accounts manager on the SCO machine. The default creates a UNIX user with Advanced Server (AFPS) access. To create a user with access to UNIX and Windows, accept the defaults and click OK to create the user. To create a user without Windows networking access, click Change Distribution. Click the button next to Local Only in the pop-up window to select Local versus Advanced Server networking.

To create a user for Windows networking only, create the user from User Manager for Domains on a client with the NT Server Tools. You can manage all user characteristics on the AFPS Server from User Manager for Domains on a Windows client, as Screen 2, shows. The user will appear in the list of UNIX users, but with a login shell of /bin/false. UNIX login shells are the command interpreters that govern the interface between the user and the operating system. The command /bin/false is a program that always returns a false or untrue response. If you attempt to log in with a shell of /bin/false, the login command will get a not logged in response. To convert this account to a usable UNIX account, change the login shell of /bin/false to a normal login shell (such as /bin/sh or /bin/ksh). The home directory for a UNIX account is where users start. Their working directory at the time they log on is their home directory. This directory contains startup control files such as .profile and .kshrc. These files are analogous to the autoexec.bat file, except that each user can have a different set of commands in the user's .profile.

Sharing Printers
You can accomplish the UNIX printer sharing from the UNIX command line. For example, suppose you have a UNIX computer with printers named hplaser1 and hplaser2 and you want to share them to PC clients. You can share them individually with the following commands:

net share laser1=hplaser1 /print

net share laser2=hplaser2 /print

Or, you can create a printer pool and share them together:

Net share laser1=hplaser1, hplaser2 /print

You can also create printers through the UNIX GUI and share them upon creation, as Screen 3 shows. To share them through the GUI after creation, double-click SystemsAdministration, and click the Printers folder. Double-click the Printer Manager icon. Highlight a UNIX printer, click Settings, and select Share printer with Windows Users. Enter a share name, and click OK.

UNIX computers can share printers connected to a Windows PC. After you share the Windows printer, use the following procedure to access it from UNIX. From the UNIX Printer Manager window, select Printer, Add Remote, and Windows to bring up the Use Shared Printer on Windows Client window. Enter a printer name, description (optional), and the printer model (passthrough is recommended and is the default). Enter the Windows client, the share name (or click Select to get a list of shared printers), and the optional password. Click OK to make the Windows printer available to UNIX applications.

Sorting Out the Details
AFPS does some things differently from NT. For instance, an AFPS UNIX machine serving as a BDC or PDC can become a BDC of another domain without the administrator reinstalling either AFPS or UNIX. When switching domains, the administrator is warned that the Security Accounts Manager (SAM) database will be reinitialized. In AFPS, you can create a user on UNIX for Windows networking on the BDC, and AFPS will update the PDC.

AFPS provides both import and export directory replication. AFPS supports trust relationships, and you can create trusts through AFPS. Windows networking rules control file permissions as a first step, and then the system checks UNIX permissions.

AFPS provides file sharing from UNIX to the PCs, but not vice versa. SCO OpenServer provides a LAN Manager Client that, when used with AFPS, provides bi-directional file sharing. Installation and management of this feature is discussed in the SCO OpenServer "Guide to Gateways for LAN Servers."

Solving a Complex Problem
SCO's AFPS is NT networking code that lets an SCO UNIX computer participate in a Microsoft network as a PDC or BDC. The SCO machine can share files and disk space with the Windows clients. You can make printers from the SCO UNIX machine available to the Windows clients and Windows printers available to the SCO UNIX programs.