3.1. Identifying Server Operating System Access to Network Resources
Although Microsoft has most of the market in regard to server operating systems, they do not have it all. You should therefore understand the capabilities of various server operating systems in regard to interoperability with Microsoft and with each other. Server operating systems can be used for a variety of tasks on a network. They can also provide resources, such as a file server, application server, or print server.
3.1.1. Critical Information
You should be familiar with the means of accessing network resources located on the most common types of server operating systems. Be able to compare and contrast the differences between the methods used to access resources on each type of server operating system.
3.1.1.1. Unix/Linux/Mac OS X Server
Unix was one of the first server operating systems to be used to provide resources on a network. Many Unix servers are still in use today, due to the legacy programs that are still used on the servers and the relative flexibility of the Unix operating system in regard to the clients that it can use. You can connect to a Unix server using the Telnet program or SSH. Unix authentication and security is accomplished in much the same way as Microsoft's newer networks, with Remote Procedure Call (RPC) and the Kerberos protocol. Unix can also use the PPP protocol for remote access authentication.
Microsoft also provides a package for clients that allows Microsoft clients to connect to and use resources and printers on a Unix server, referred to as Services for Unix. Clients can use the Line Printer Requester (LPR) protocol to connect to Unix servers running the Line Printer Daemon (LPD) protocol. Despite Unix's flexibility in regard to clients, most companies do not use Unix servers anymore. This is partially due to the fact that much of the configuration of Unix server was originally accomplished through a "not so user friendly" command prompt, although newer versions of Unix, such as Solaris and AIX, now offer a robust GUI.
Linux is a "spin-off" of Unix, first developed by Linus Torvalds and a number of enthusiastic developers in 1991. Linux is an open source operating system, which means you can download the kernel for free. However, there are many distributors—such as Red Hat and SUSE—who offer installation help, online and telephone support, and other freeware applications on one convenient CD for a fee.
Linux boasts an open source architecture, which means that you can make real changes to the way that it operates. If you don't like something about Linux, you can just change a few things and make your own new version. While this fact has aided the growth of Linux, especially within the circles of computer software developers, it's also limiting the acceptance of the software by "big business." This is due to the fact that big business relies on standardization, which Linux (because of its open source nature) has been unable to provide. This is gradually changing and Linux may begin to give Microsoft a "run for their money" in the near future.
As with Unix, you can use Telnet to connect to and manage Linux servers; however, you can also use an array of GUI tools provided by Linux. Linux uses the TCP/IP protocol, which makes it largely interoperable with Microsoft and with AppleTalk for IP. It also uses Lightweight Directory Access Protocol (LDAP) for its databases, which makes it interoperable with Microsoft Active Directory as well as Novell Directory Services. In regard to security, like Unix, Linux is capable of using the Kerberos authentication protocol for local connections and PPP authentication for remote connections.
For file and print services, Linux clients can use Samba (from the Server Message Block protocol or SMB), which is a suite of programs that implement the SMB protocol on Linux. The SMB protocol is the foundation of Windows networking, or as Microsoft now calls it, the Common Internet File System (CIFS). The latest version of Samba, 3.0.10, includes many new features to increase compatibility with Windows 2000 and Windows Server 2003 domains.
Mac OS X Server is a Unix-based product from Apple computers. It is a newer server product that was designed for today's networks and for the use with the TCP/IP protocol rather than a proprietary protocol from Apple. Mac OS X Server can also act as a web server for many types of clients. It uses Kerberos authentication for a secure single signon to all of the resources to which a user is given permissions. It can also use the latest features such as Wired Equivalent Privacy (WEP) for wireless networks and virtual private networking (VPN) for secure access to remote corporate networks. Since it is Unix based, it offers all of the same file and print capabilities and application support as the Unix and Linux servers, such as the latest versions of Samba.
3.1.1.2. NetWare
NetWare is a server operating system produced by Novell. First introduced in the early 1990s, NetWare has been through many revisions and is now one of the most secure and fullfeatured operating systems available today. Many administrators feel that NetWare has actually been a more secure and more manageable server product than any other over the years. Many administrators know nothing except NetWare and and therefore will not give it up. Despite this fact, Novell continues to lose market share to the latest Microsoft server operating systems. NetWare servers do, however, make excellent file servers because of the way their NFS file system indexes all of the information on the computer.
There are many ways to connect to a NetWare server. You can do so using a Novell client software installed on the client computer over the operating system of your choice. In addition, Microsoft provides a tool called Client Services for NetWare (CSNW), which allows its clients to connect directly to a NetWare server, and a tool called Gateway (and client) Services for Net-Ware (GSNW), which allows a client to connect to a Microsoft server that is connected to a NetWare server. When you install these tools, the NWLink protocol that emulates the Novell IPX/SPX protocol is also installed. This allows additional connectivity to the Novell server, although the latest Novell servers use TCP/IP, not IPX/SPX, as their default protocol. You can also use the Telnet protocol to connect to and manage NetWare servers.
3.1.1.3. Windows
When you just say "Windows" to describe all of the server operating systems that Microsoft has released over the years, that's a little like saying "cars" to describe what has come out of Detroit's assembly lines. In other words, there have been many operating systems and many service packs for each of the operating systems, which, in some cases, dramatically changed the capabilities of the operating system. Rather than discussing all of the details of each of the server operating systems produced by Microsoft, we will instead focus on the commonalities of the server operating systems in regard to the methods that a client can use to connect to the server and use resources contained on the server. All of the newest operating systems (beginning with Windows 95) have Microsoft Client included in the software.
There are many ways in which Microsoft clients can connect to and use resources on a Microsoft server. The following is a list of the most common methods used:
Network Neighborhood/My Network Places
This is a server and share location service (shown in Figure 3.1) that provides a GUI-based tool on which users can point and click to connect to resources. The list of resources is frequently updated automatically by the browsing service on the network. These tools can also be located within the Windows Explore and My Computer tools.
Figure 3.1. My Network Places
Mapped network drives
Users and administrators can use the Windows Explore tool (shown in Figure 3.2) to map a network drive and make it easily accessible in the future.
Universal Naming Convention (UNC) command
You can access shared resources on a Microsoft network by typing the UNC command that indicates the server where the resources are stored and the name of the share that identifies the resources. The syntax for the UNC command is \servershare, where server is the name of the server that contains the resource and share is the name of the shared folder or other resource on the server.
Remote Desktop Connection
You can connect to a server remotely from a client or another server, provided that you have the permissions and the server to which you are connecting is configured to accept the connection. Users can also use Remote Desktop Connection to connect to resources and programs on a server. You can configure Remote Desktop Connection to allow a user to connect to a server resource and automatically run a program that provides access to a line-of- business application. In this way, you can enable users to utilize their PCs more like dumb terminals to connect to and use specific resources.
Microsoft also makes sure that their networks are accessible to other clients. Most client operating systems such as Novell, Unix, Macintosh, and Linux have software that allows them to connect to and use resources on a Microsoft network. While they may not have all of the options that the Microsoft clients have, most do have the general capability to connect to the resource.
Figure 3.2. Mapping a network drive
3.1.1.4. Appleshare IP (Internet Protocol)
Appleshare IP is a service from Apple that is specifically designed to provide secure remote access for Macintosh clients to Mac OS X Servers. We will discuss this service in greater detail later in this chapter in the section on remote access.
3.1.2. Exam Essentials
Describe the capabilities of Unix servers. Unix servers are still in use today largely because of their high degree of flexibility in regard to applications and clients. Most connections to a Unix-based server are made using Telnet or another, more secure remote protocol. Unix is still mostly command line driven and does not offer the GUI tools that other operating systems offer.
Be familiar with the capabilities of Linux. Linux is a spinoff from Unix, but it does provide a GUI. Linux servers can be accessed using Telnet or an array of tools provided by Linux clients. The main distinction of Linux software is its open source architecture, but this distinction is also a disadvantage because of the lack of standardization of the product.
Know the capabilities of Mac OS X Server. Mac OS X Server is a newer product designed to be used with Macintosh clients and other computers. Mac OS X is designed to use TCP/IP instead of the proprietary Apple protocols. Mac OS X Server can make a good web server for many clients.
List the capabilities of NetWare. NetWare is a server system developed by Novell. It offers an array of command-line and GUI-based tools that you can use to administer a network. NetWare clients typically consist of computers that have Microsoft operating systems installed along with the Novell client network and operating system. Microsoft also offers a client operating system that allows a Microsoft client to connect to a NetWare server (CSNW). The clients can also connect to a NetWare server by first connecting to a Microsoft server and then using a gateway connection provided by the Microsoft server (GSNW).
Know the capabilities of Microsoft Windows client software. All of the newest Microsoft operating systems (beginning with Windows 95) have Microsoft Client included in the software. The Microsoft Client software allows the user to connect to a Microsoft network in a number of different ways, including Network Neighborhood/My Network Places, mapped network drives, UNC commands, and remote desktop connection. Microsoft also makes its networks accessible to other clients such as Novell, Macintosh, and Unix clients.
Describe the characteristics of the Appleshare IP protocol. The Appleshare IP protocol is a relatively new client operating system designed by Apple to be used with Macintosh clients and the TCP/IP protocol. Appleshare IP is specifically designed to be used as a remote access server and has tools that allow secure remote access for Macintosh clients.