NET 121b: Essentials of Networking

Chapter 14: Network Operating Systems


This chapter discusses network operating systems from several vendors, and variations on each of them. The topics of this chapter are:

  1. Windows
  2. NetWare
  3. UNIX and Linux
  4. Mac OS X and Appleshare IP

The chapter describes features of three families of Windows servers: NT, 2000, and 2003.

NT servers and workstations run operating systems that Microsoft no longer supports, but some companies may be using NT because they have no funding for upgrading hardware, software, or both. When it was marketed by Microsoft, NT software came in four varieties:

  • Windows NT Workstation: used on workstations meant to connect to NT servers
  • Windows NT Server: the basic NT server software
  • Windows NT Server - Enterprise Edition: a more robust NT server for mission-critical applications and for larger networks
  • Windows NT Server - Terminal Server Edition:a version of NT server that let administrator connect non-Windows devices to the network

NT facts:

  • All the versions above are 32-bit operating systems that support networking.
  • NT supports locking down the workstation or server, so that only a user who logs in with specific privileges can install/uninstall software and perform tasks that might damage the system. The default account on an NT system that has such privileges is called Administrator. The text refers to this account as a superuser account.

Windows 2000 is also an operating system no longer sold for workstations and servers. The text lists four versions of it:

  • Windows 2000 Professional - a version for workstations; it can act as a peer, but is not meant to be used as a server
  • Windows 2000 Server - the basic Windows 2000 server; can be used on computers with up to 4 processors and up to 4 GB of RAM
  • Windows 2000 Advanced Server - for medium network servers; can be used on computers with up to 8 processors and up to 8 GB of RAM
  • Windows 2000 Datacenter Server - for large network servers; can be used on computers with up to 32 processors and up to 32 GB of RAM; also supports clustering (configuring several servers to act as one)

Windows 2000 facts:

  • Clustering supports load balancing
  • Active Directory, a network directory service, was first seen in Windows 2000. Active Directory stores information about network users and resources, and allows an administrator to manage them.
  • Microsoft Management Console (MMC) is used to manage servers and workstations. It was available with NT 4.0, but is standard on Windows 2000.

Windows Server 2003 has no workstation version, but it still comes in several versions:

  • Windows Server 2003 Web Edition - made for web services, supports up to 2 GB of RAM
  • Windows Server 2003 Standard Edition - the standard, smallest version; supports up to 4 processors, up to 4 GB of RAM
  • Windows Server 2003 Enterprise Edition - for servers running mission-critical applications; supports 64 bit processing, up to 8 processors, and up to 32 GB of RAM (64 GB of RAM with Release 2)
  • Windows Server 2003 Datacenter Edition - available in 32 and 64 bit versions; made to provide scalability for web based data services; can support up to 128 GB of RAM

Windows Server 2003 facts:

  • Uses Microsoft's .NET platform
  • Improved clustering, load balancing, and security
  • Software Update Service (SUS), used for managing/installing workstation software

NetWare is the name of several versions of a network operating system developed by Novell. The list of features presented in the text is trivial: most of these features are found on all networks.

NetWare facts:

  • NetWare is up to version 6.5 as of this writing.
  • NetWare version 4 and later include what was originally called Novell Directory Services (NDS) and is now called eDirectory. This is a network directory service, similar in intent to Microsoft's Active Directory. eDirectory can be loaded on a Novell server, a Windows server, a UNIX server, or a Linux server. It can provide directory services for a network that includes all these operating systems.
  • NetWare 3 and earlier version did not include NDS. They used a flat-file database system called a Bindery. Each server had its own Bindery service to manage resources associated with it.
  • A NetWare server cannot be used as a workstation, unlike a Windows server.
  • The default administration ID on a NetWare system is called Admin. (This ID was called Supervisor in NetWare 3 and earlier versions.)
  • In NetWare 4.11 and earlier versions, the default protocol suite is the IPX/SPX suite. NetWare 5 and later versions support IPX/SPX, but also provide native support for TCP/IP.
  • User accounts on dissimilar systems can be synchronized with Novell DirXML, also called Novell Nsure Identity Manager.
UNIX and Linux

UNIX was developed at Bell Labs in 1969. It was an attempt to improve on the characteristics of computer systems that frustrated computer professionals at the time.

UNIX comes in two basic flavors. The AT&T version is descended from the researchers at Bell, and is called SVR4. This means System V (that's a Roman 5) Release 4. The second type is called BSD, for Berkeley Standard Distribution. It is descended from the version that evolved from the many changes made at the University of California at Berkeley. What were they doing with it? Well, Bell Labs couldn't sell UNIX at the time, so they gave it away to schools, who changed to to suit themselves. If only Bell could have sold it, maybe it could have evolved into Windows, and no one would have ever heard of Bill Gates.

Features found in UNIX are also found in DOS, Windows, NetWare and other systems that were developed after UNIX.

Facts about UNIX:

  • The administrative user on a UNIX system is called Root.
  • UNIX is very case sensitive. On a Windows system, a file might be called by any version of its name: upper case, lower case, or mixed case. A UNIX system will consider each of these filename variations to be different and unique. The same case distinctions apply to UNIX commands and utilities.
  • There are many varieties of UNIX. Some major vendors are Sun, Hewlett Packard, IBM, and Santa Cruz Operation (SCO).

In 1991, Linux was developed as a low cost alternative to UNIX by Linus Torvalds in Finland. Several versions of it have been developed since, and marketed by several developers. Free versions also exist.

Linux facts:

  • Linux is an open source operating system. Anyone may submit an improvement to the system.
  • Some vendors that sell Linux versions: Novell, Red Hat, Denebian.
Mac OS X and Appleshare IP

Mac Operating System X (Roman 10) is an operating system for Apple Macintosh computers. It is based on BSD UNIX and other components from the NeXT company, which was run by Steve Jobs, a founder of Apple.

Mac OS X facts:

  • Mac OS X Server supports clients that run Windows, UNIX, and Macintosh operating systems.
  • The directory service provided by Mac OS X is called Open Directory 2. It supports Lightweight Directory Access Protocol (LDAP).

Appleshare IP was a product from Apple that supported clients that used TCP/IP or Apple's proprietary Appletalk protocol. It was discontinued in favor of Mac OS X. The text notes that it supported up to 500 users, and up to 50 web sites.