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Guide to Networking EssentialsFifth Edition
Chapter 8Simple Network Operations
Guide to Networking Essentials, Fifth Edition 2
Objectives
• Explain the operation fundamentals of network operating systems
• Describe networking software components
• Describe the basic steps of network operating system installation
• Configure network services
• Explain network application installation and configuration concepts
Guide to Networking Essentials, Fifth Edition 3
Network Operating Systems
• Network operating system (NOS): OS with functions that facilitate network communication, allow computer resources sharing on a network, and provide access control to those resources– Interface for users and applications to access the
network and its resources– Introduced during the mid-1980s– Handle standalone computer activities as well as
communication over the network– E.g., Novell NetWare, Windows Server 2000/2003,
UNIX, and Linux
Guide to Networking Essentials, Fifth Edition 4
Basic Functions of an Operating System
• OS coordinates interaction between software applications and computer hardware
• Most applications are written so that they can be used only with a particular OS family
• Two features necessary in a NOS– Multitasking: capability to support numerous
processes at one time– Time slicing occurs when the CPU’s computing
cycles are divided between more than one task• Human inability to distinguish instances of this brief
time period creates the illusion of multitasking– Every contemporary OS includes these functions
Guide to Networking Essentials, Fifth Edition 5
Basic Functions of an Operating System (continued)
• Two types of multitasking– Preemptive multitasking
– Cooperative multitasking
• A true high-performance NOS must be a preemptive multitasking system– All contemporary operating systems are designed to
use preemptive multitasking
• OSs include many NOS features– Some of these features are still reserved for OSs
designed to be installed on a server computer
Guide to Networking Essentials, Fifth Edition 6
Software Components of Networking
• NOS manages computer’s activities and provides a network environment– Organizes hardware into an interactive whole– Coordinates/controls functions of
machines/peripherals– Supports security and privacy (network and users)– Controls access to resources (user authentication)– Advertises/manages resources (centralized
directory)– Provide access to shared resources
• NOS components: naming services, directory services, and client and server software
Guide to Networking Essentials, Fifth Edition 7
Naming Services
• On most networks, a name is necessary to identify and access resources of all kinds
• Humans recognize symbolic names more easily than numeric names– Naming services translate symbolic names into
corresponding network addresses
• This chapter explains the relationship between how Microsoft uses NetBIOS names and how the TCP/IP-based Domain Name System uses domain names
Guide to Networking Essentials, Fifth Edition 8
NetBIOS Names
• Names can be no longer than 15 characters
• Ending a name with $ prevents it from appearing in the NetBIOS browse list
Guide to Networking Essentials, Fifth Edition 9
NetBIOS Names (continued)
Guide to Networking Essentials, Fifth Edition 10
Universal Naming Convention
• Drive mapping: process of associating a network storage resource with a local drive letter
• Windows and Linux (running Samba) OSs and most other modern NOSs recognize Universal Naming Convention (UNC) paths, a standard method for specifying network resources– \\servername\sharename– In UNC-aware applications and many command-line
activities, a UNC path can be used instead of a drive letter to access a network resource
Guide to Networking Essentials, Fifth Edition 11
Domain Names and DNS
• DNS translates symbolic domain names into numeric IP addresses– Permits users to access resources and services by
using symbolic domain names on the Internet
• DNS server maintains a DB of computer name and IP address pairs– At least one DNS server is maintained for a domain– Domain: named logical grouping of network resources
• E.g., course.com– When a network request for www.course.com is
made, the request is sent to the DNS server responsible for the course.com domain
Guide to Networking Essentials, Fifth Edition 12
Directory Services
• Directory service: manages information about network services, resources, users, groups, and objects so that users can access resources and services by browsing or asking for them by type– Manages and controls access to network resources– Access control (stores info and performs checks)– E.g., Windows’ Active Directory, Novell’s eDirectory
• Uses “tree and forest” metaphor to organize contents• Patterned after X.500 directory service
– LDAP is far easier to implement
– Most Linux versions include NIS
Guide to Networking Essentials, Fifth Edition 13
Client Network Software
• Client network SW: part of NOS installed on PCs that access network services or network resources– Most important component is a redirector
• SW component operating at the OSI model’s layer 6 that is found on both client and server NOSs
• Hides from users the complicated tasks involved in accessing network resources
– Designator: aids in network resource interaction• Keeps track of the drive letters assigned locally to
remote or shared drives– A shared drive is known as a share
– Client SW can refer to Internet access applications
Guide to Networking Essentials, Fifth Edition 14
Server Network Software
• Server SW can restrict access to resources by using access controls– Also: user/group management, logon authentication,
network administration, fault tolerance
Guide to Networking Essentials, Fifth Edition 15
Server Network Software (continued)
Guide to Networking Essentials, Fifth Edition 16
Client and Server Capabilities
• Many NOSs (e.g., Windows Server 2003, XP, Vista) include client and server capabilities in both the server and desktop versions– Generally, the desktop version of the NOS is not as
powerful or robust as the server version
• Novell NetWare is strictly a server NOS, so there’s no desktop version of NetWare
• In Linux, the choice between a desktop or server installation is usually made during installation
Guide to Networking Essentials, Fifth Edition 17
Installing a Network Operating System
• Installing an NOS is not much different than installing a standard desktop OS– Requires only a few additional steps focused on
configuring the network and the server services – Before installation of an NOS can begin, however,
you must complete a few preparatory steps
Guide to Networking Essentials, Fifth Edition 18
Installation Preparation
• Before you begin an NOS installation, you need to understand the following network aspects:– Size of the network– Job requirements of the server– Organization of storage devices– File systems to be used– Identification or naming convention– Network adapter configuration– Protocol selection– Hardware compatibility
Guide to Networking Essentials, Fifth Edition 19
Size of the Network
• The size of a network can affect which services you decide to configure, how many servers you need, and the number of connection licenses you require– A small LAN with fewer than 10 users who require
only file and printer sharing can probably function fine with a peer-to-peer network
• Windows XP or Vista could serve as the OS
– With more users or more advanced networking service requirements, a dedicated server with an NOS designed for servers is definitely in order
Guide to Networking Essentials, Fifth Edition 20
Server Job Requirements
• The services and resources hosted by a server determine what components are installed– E.g., DNS, DHCP, Web services, remote access, etc.
• Other server responsibilities– Domain controller: authenticates users and maintains
directory services and the security DB for a domain• For fault tolerance, install at least two per domain
– Member server: hosts a service or resource and doesn’t maintain the directory and security DB
• In NetWare, use existing tree or create new one• In Linux, decide individual services to install
Guide to Networking Essentials, Fifth Edition 21
Storage Device Organization
• Crucial to network’s success when accessibility, performance, and fault tolerance are essential
• Partition: logical organization of disk space; each partition appears as a separate logical drive
• Ways to organize NOS host drive– Multiple-boot: good for testing; not good for security– Single-partition, single-NOS: most secure– Multiple-partition, single-NOS: useful for separating
data from OS files; increases drive activity– Fault-tolerant storage: e.g., disk mirroring, RAID
Guide to Networking Essentials, Fifth Edition 22
File Systems
• File system: method used to store, organize, and manage access to files on a mass storage device– File systems differ in how they allocate space, how
files are located on disk, the level of fault tolerance, and how access to files is secured
• Fault-tolerant features include backup copies of FAT, journaling
• Folder- and/or file- level security are important– E.g., as provided by NTFS or ext3– It’s best to use the most secure file system available for
the OS you’re installing
Guide to Networking Essentials, Fifth Edition 23
Naming Conventions
• Naming convention: method of creating names– Should have scheme for user accounts, computers,
directories, network shares, printers, and servers– Common naming schemes
• Construct user names from the user’s first and last names, plus a code identifying job title or department
• Construct group names from resource types, department names, location names, project names
• Construct computer names for servers and clients from their department, location, and an ID number
– Must be consistent, easy to use and understand, and must enable clear object identification
Guide to Networking Essentials, Fifth Edition 24
Network Adapter Configuration
• The NIC is the primary communication device between a computer and the rest of the network– A computer purchased as a server already has an
NIC installed• Must verify manufacturer and model number to ensure
compatibility and update device drivers as necessary
• Most NICs are plug-and-play-compatible with the OS, so NIC configuration isn’t usually necessary
– Verify compatibility with the OS version you are using, and have a driver disk ready in case the OS doesn’t recognize the NIC
Guide to Networking Essentials, Fifth Edition 25
Protocol Selection
• Protocol and configuration options must be compatible for computers to communicate– For example, TCP/IP requires the following pieces of
information before NOS installation begins:• IP address
• Subnet mask
• Default gateway
• DNS
• WINS
• DHCP
Guide to Networking Essentials, Fifth Edition 26
Hardware Compatibility
• HW components of the computer on which it’s installed must be compatible with the NOS– If you use incompatible hardware, the vendor might
not provide technical support– Double-check that your computer’s HW components
are fully compatible with the NOS• Microsoft publishes the Windows Catalog
– Formerly called the Hardware Compatibility List (HCL)
• Linux distributors publish a similar list for the various Linux versions
• Novell typically certifies whole systems as NetWare compatible
Guide to Networking Essentials, Fifth Edition 27
Installing Microsoft Windows Servers
• Windows server versions are not much more difficult to install than Windows XP or Vista
• With the proper preparation, the Setup Wizard makes the installation process as simple as entering a few key data items– The major steps or sections of the installation
included here give you insight into the architecture and simplicity of the Windows server line of operating systems
Guide to Networking Essentials, Fifth Edition 28
Beginning the Installation
Guide to Networking Essentials, Fifth Edition 29
Text-Based Phase
Guide to Networking Essentials, Fifth Edition 30
GUI Phase
• In the GUI phase, you use a mouse or keyboard to enter items or make selections
• You define computer and domain names, enter the identification key from installation CD, select the server type (domain controller or member server), assign a password to Administrator account, select environment and desktop components
• Setup copies some files from the temporary folder to the destination folder and then moves into the network setup phase
Guide to Networking Essentials, Fifth Edition 31
Network Setup Phase
• You install drivers for the NIC, select and configure protocols, and review bindings
• Upon completion, files are copied to the system folder and temporary folder is deleted– Next, you define time zone and display settings– Then, the computer restarts, the Administrator logs
on, and the Configure Server Wizard starts• Allows the server to be configured as a domain
controller, member server, or standalone server– If server is to act as a domain controller, Active
Directory is installed and configured
Guide to Networking Essentials, Fifth Edition 32
Installing Novell NetWare 6.5
• Install NetWare by using one of two methods– Over the network– From a CD
• The primary install utility is INSTALL.NLM– Two phases
• Text mode– Create partitions, accept license agreement, copy files,
install storage device drivers, and select NIC drivers
• GUI mode– Assign server name, set up protocols, and install
eDirectory
Guide to Networking Essentials, Fifth Edition 33
Installing Linux
Guide to Networking Essentials, Fifth Edition 34
Installing Linux (continued)
Guide to Networking Essentials, Fifth Edition 35
Installing Linux (continued)
Guide to Networking Essentials, Fifth Edition 36
Configuring Network Services
• Network services, the basic resources on all networks, are the foundation of network applications
• The two most basic shared network resources (network services) are printers and file folders
• You can add numerous capabilities, resources, and delivery methods to a default NOS installation– Groupware applications, e-mail packages, shared
whiteboard applications, Web servers, etc.
Guide to Networking Essentials, Fifth Edition 37
Installing, Removing, and Configuring Network Services
Guide to Networking Essentials, Fifth Edition 38
Network Bindings
• Binding: process of linking network components from various levels of the network architecture to enable communication between those components – Associate upper-layer services and protocols to
lower-layer network adapter drivers– Many NOSs enable all valid bindings by default
• Often results in some performance degradation
• Binding order should enhance the computer’s use of the network– Bind the most frequently used protocol, service, or
adapter first to speed network connections
Guide to Networking Essentials, Fifth Edition 39
Network Printing
• It is one of the two essential network services
• Redirector intercepts print requests and forwards them to the right print servers or network printers
• Three components: the print server, the print queue, and the printer– First, installing a printer on a server or as a direct
network-connected device– Next, share printer’s logical representation in NOS– Print queue is a storage location that accepts print
jobs from network clients and stores the print job until the printer is available to print it
Guide to Networking Essentials, Fifth Edition 40
Network Printing (continued)
Guide to Networking Essentials, Fifth Edition 41
Printer Management
• On most networks, you manage printers from local direct access or through the network printer share– Sometimes you may use a Web browser (e.g., IPP)
– Must have right level of access granted to user
– Printer management covers wide range of activities• Granting and restricting user access to printers
• Monitoring the print queue for proper functioning
• Limiting access (time frame, department, or priority)
• Updating local and remote printer drivers
• Maintaining printers
• Managing printers remotely
Guide to Networking Essentials, Fifth Edition 42
Sharing Fax Modems
• This feature is not often a default component in an NOS; many third-party vendors offer add-on products to share a fax modem over a network– With these add-on products, clients can fax
documents from the desktop– You can manage and administer fax shares just like
printer shares– Usually, additional client-installed software is needed
to connect to a fax share• After drivers are installed, there’s no major difference
between using a printer share and a fax share
Guide to Networking Essentials, Fifth Edition 43
File Shares
Guide to Networking Essentials, Fifth Edition 44
Network Applications
• Network applications: designed for multiple simultaneous users on computers on a network
• Three types of essential network applications: messaging, scheduling, and groupware
• Pros– Much easier to administer (e.g., on large networks)– Save money
• Cons– Poor network performance degrades performance– If network is down, application is often unusable
Guide to Networking Essentials, Fifth Edition 45
Network Applications (continued)
• At least three types of architectures for network applications– Centralized– File-system sharing– True client/server
Guide to Networking Essentials, Fifth Edition 46
E-Mail or Messaging
• Most popular network application
• E-mail is fast and asynchronous
• Based on a common protocol and standards for communication– Post Office Protocol version 3 (POP3)– Simple Mail Transport Protocol (SMTP)– Internet Message Access Protocol (IMAP)– X.400– X.500– Message Handling System (MHS)
Guide to Networking Essentials, Fifth Edition 47
Scheduling or Calendaring
• A network scheduler is an electronic form of an appointment book and to-do lists– Most offer private and public calendars, appointment
books, task lists, and contact/address books– They can also notify about upcoming meetings, warn
about overlapped schedules, and offer reminders of special events or the need to contact someone
– Most offer integration into e-mail programs and office-productivity suites
– To supplement or replace a paper-based personal information manager, schedules can be printed
Guide to Networking Essentials, Fifth Edition 48
Groupware
• Groupware enables multiple users to interact with a single file, document, or project– E.g., an entire department can contribute to a
document’s production and watch as the groupware combines everyone’s input into a single document
– Examples: multiuser multimedia authoring tools, Lotus Notes, Novell Virtual Office, and HP’s TeamLinks
– Some make it possible to collaborate across the Internet
– The biggest explosion in groupware products is integrating PDAs with corporate networks
Guide to Networking Essentials, Fifth Edition 49
Summary
• Network operating system (NOS): controls the operations of a computer, including local hardware activity as well as communication over network media– Enables sharing resources, managing peripherals,
maintaining security, and controlling user access
• Client network software on workstations allows users to take advantage of network resources– Doesn’t always mean redirectors and designators
• Server network software is designed to host resources so that multiple clients can access them
Guide to Networking Essentials, Fifth Edition 50
Summary (continued)
• Installing an NOS is similar to installing any OS– Issues you must be aware of include size of the
network, job requirements of the server, storage device organization, naming conventions, NIC and protocol selection and configuration, and hardware compatibility
– The steps for installing Windows Server 2000/2003, Novell NetWare, and Linux are similar
• Two fundamental network services: sharing printers and sharing files
• Some standalone applications have been revised to function as cross-network applications