Download Understanding Networks

Understanding Networks I
Objectives
• Compare client and network operating
systems
• Learn about local area network
technologies, including Ethernet, Token
Ring, FDDI, and wireless
• Use the OSI model to understand
networking
• Learn how network computers and servers
are addressed
Operating Systems on the
Network
• A desktop computer requires an operating
system, such as Windows 98, Windows 2000, or
Windows XP, to manage its application,
hardware, and connection to the network.
• The operating system is also responsible for
enabling the computers on the local area
network (LAN) to share their resources.
• The term resources refers to any files,
databases, or printers installed on or attached to
a computer.
Operating Systems on the
Network (Continued)
• In a peer-to-peer model, several computers using
different operating systems in a small business or
home can be connected to form a small LAN.
• The process of entering a correct user ID and
password and gaining access to a computer is
called authentication, validation, or logging on.
• A user account is a collection of all of the
information that pertains to a user on a computer.
Operating Systems on the
Network (Continued)
• A network operating system (NOS), such as
Windows Server 2003, Windows 2000 Server,
UNIX, or Novell NetWare can be installed on a
server and used to manage network resources,
including user accounts, printers, and file
sharing across the LAN.
• In a client/server model, sometimes called a
domain model, a server is used to control which
resources on the LAN are shared, and who can
access these resources.
Windows NT Workstation, Windows
2000 Professional, and Windows XP
• One of the oldest that is still in use is
Windows NT.
• It offers two operating systems, Windows
NT Workstation and Windows NT Server.
• Windows NT Workstation does not have
the Device Manager user interface.
Windows NT Workstation, Windows
2000 Professional, and Windows
XP (Continued)
• The Windows 2000 OS family has four different
operating systems, depending on your needs:
Windows 2000 Professional, Windows 2000
Server, Windows 2000 Advanced Server, and
Windows 2000 Datacenter Server.
• Windows XP comes in three different operating
systems: Windows XP Professional, Windows
XP Home Edition, and Windows XP 64-Bit
Edition.
Linux
• Linux is very different from Windows.
• To evaluate Linux as an operating system,
you need to understand the difference
between an operating system kernel and
an operating system shell.
• The operating system kernel is the part of
the operating system that interfaces with
applications, software cannot command
the kernel directly, but must go through a
command interface called the shell.
Linux (Continued)
• In Windows, the GUI shell is the default
shell.
• If you want a command-line shell, you
must open the Command Prompt window.
• In contrast, Linux and UNIX use a
command-line shell as the default shell.
Macintosh Operating System
• Several versions of the Macintosh operating
system (MacOS) are available for Macintosh
computers, the latest being Mac OS X (ten).
• OS X provides easy access to the Internet and
allows any Macintosh computer to become a
Web server for a small network.
• The Mac OS uses a suite of networking
protocols called AppletTalk, but also supports
the networking protocol suite TCP/IP so it can
access the Internet.
Network Protocols
• In addition to one or more operating systems, a
network also requires a network protocol so all
computers on the network can communicate.
• To communicate, all computers including the
NOS on the server, must use the same network
protocol.
• The selected network protocol must be
supported by every operating system on the
network.
Network Operating Systems
• Some criteria to consider when selecting a
NOS are as follows:
– Reliability
– Performance
– Adaptability
– Affordability
– Security
– Scalability
– Ease of use and ease of installation
Network Operating Systems
(Continued)
• A domain is a centralized administrative system
that uses a database to group and manage
network resources, such as users, computers,
printers, and additional network devices.
• The domain controller authenticates user
logons, applies security policies, manages
shared resources, and maintains the directory
database used by all elements on the LAN.
Windows NT Server and
Windows NT Enterprise Server
• One Windows NT Server computer is
designated as the primary domain controller
(PDC), which stores and controls a database of
user accounts, group accounts, and computer
accounts.
• This database is called the directory database or
the Security Accounts Manager (SAM)
database.
• Each computer with a backup of the directory
database is called a backup domain controller
(BDC).
Windows 2000
• The other three Windows 2000 operating
systems are:
– Windows 2000 Server
– Windows 2000 Advanced Server
– Windows 2000 Datacenter Server
• A Windows 2000 Server domain is
organized differently from a Windows NT
domain because Windows 2000 Server
does not use backup domain controllers.
Windows 2000 (Continued)
• Windows 2000 uses one or more domain
controllers that replicate the database among
themselves.
• Active Directory is a centralized system that
controls computer and user configuration
settings, security settings, and access to
resources on a LAN.
• It uses a hierarchical organization that provides
the administrator with a single place for all
system administration, including user and
computer configuration and management.
Windows Server 2003
• A Windows Server 2003 domain is
organized in much the same manner as a
Windows 2000 Server domain.
• Windows Server 2003 keeps lists of
resources on the network in an Active
Directory database.
Novell NetWare
• NetWare by Novell, Inc. was, for many
years, the tried-and-true, industryaccepted solution to LAN management.
• In versions of NetWare up to 5.0, the
default protocol is a suite of protocols
collectively called IPX/SPX, which also is
supported by Windows 98, Windows NT
Workstation, Windows 2000 Professional,
and Windows XP.
Novell NetWare (cont’d)
• The IPX portion of the protocol is
responsible for routing, and the SPX
portion of the protocol manages error
checking, similar to the way TCP manages
error checking and IP manages routing on
a TCP/IP network.
UNIX and Linux
• UNIX was the first, and still is the most popular,
NOS for midsize servers responsible for
supporting thin clients.
• Linux was mentioned earlier as an operating
system for a personal computer, but is quickly
becoming a viable option as a NOS.
• Red Hat, Inc. sells an impressive version of
Linux that has proven to be competitive as a
NOS for Internet services.