Networking Basics

The Hardware Side of Networking A network is two or more computers that have been connected for the purposes of exchanging data and sharing resources. Networked shared resources range from printers, CD-ROMs, and modems to files and hard drives. Networks vary in size and scope.

Many types of computer networks exist, but you need only be concerned with the following: Peer-to-peer network: This type of network includes two or more PCs that are connected to share data files, a printer, or other resources.

Local area network (LAN): A small business or corporate department may install a LAN that interconnects from two to hundreds of PCs, using permanently installed cabling or perhaps a wireless technology.

Wide-area network (WAN): A corporation may maintain a WAN using dialup, leased, or other dedicated communication means.

A+ Certification: Networking You should also be familiar with the following network terminology and characteristics: Topology: The geometric arrangement of any network is its topology. The most common topologies are the bus, star, and ring topologies. Protocol: To operate efficiently, any communications-based system must have an established set of rules — its protocol — to govern its operation. Popular protocols for LANs are TCP/IP and IPX/SPX.

Data packets: Data, messages, and tokens that are transmitted on any network must conform to the size and format prescribed under the network's protocol. Data packets also vary between network operating systems (NOSs) on the same protocol. Architecture: A network can be classified as being either a peer-to-peer or a client/server architecture. When all nodes on a network are equal and resources are shared equally, the network is a true peer-to-peer network. When one computer is designated to host programs or files for the rest of the network, it is a server, and the other nodes are clients.

Media: Nodes on a network are connected by twisted-pair copper wire, coaxial cable, fiber- optic cable, or wireless radio wave connections. Server: This is a network computer from which workstations (clients) access and share files, printers, communications, and other services. Servers can be dedicated to a single service, such as file servers, print servers, application servers, Web servers, and so on. Servers can also be the software that performs, controls, or coordinates a service or resource.

Node: This is any addressable network point, including workstations, peripherals, or other network devices. The term node is commonly used interchangeably with workstation. Workstation: This is a personal computer that runs application or utility software and uses data that is stored locally or provided by a network server to which it is connected by a cable or media. Workstations are also known as clients.

The Network's Domains A domain has several different uses. The three common uses of domains in networking are the following: Windows NT/2000/XP domain: A logical group of computers with centralized security and administration. Windows NT/2000/XP domain: A logical group of computers with centralized security and administration. Internet domain: An element of the Domain Name Server (DNS) naming hierarchy. Internet domain: An element of the Domain Name Server (DNS) naming hierarchy. NetWare domain: The memory segment within NetWare that is used to separate NetWare Loadable Modules (NLMs) from the operating system. NetWare domain: The memory segment within NetWare that is used to separate NetWare Loadable Modules (NLMs) from the operating system.

Internet Domains The highest level of generalized domains defined by DNS is standardized to group domain names by their organization type or geographical location. The generic top-level domains (gTLDs) that are used on the Internet are listed here. Generic Top-Level Domains (TLDs) TLDPurpose.aero Air-transport industry.bizBusinesses.com Unrestricted, but intended for commercial entities.coopCooperatives.edu U.S. educational institutions.gov U.S. government agencies.info Unrestricted use.int Organizations created through international treaties.mil U.S. military.museu m Well, museums.name Individuals (people).net Unrestricted use, but intended for network access providers.org Unrestricted use, but intended for nonprofit organizations and organizations that don't fit elsewhere.pro Professional service providers, such as accountants, lawyers, and physicians

Network Domains Servers and workstations are classified into domains by the role that they play on the network. Network domains, domain controllers, and the names of the resources in a domain are important things to know for the exam.

In the context of a Windows NT Server, Windows 2000 Server, or a Windows Server 2003 network, a domain is a collection of hardware and software resources and the user accounts that have access to them. The resources may include multiple servers, printers, CD-ROM drives, RAIDs, and other devices that are attached to the network.

Several types of servers can exist on a network, each one performing a different task for the network and its workstations. A server is usually thought of as a computer, but a server is actually the software that performs, controls, or coordinates a service or resource. One computer can physically house many different software servers. To network clients, each server can appear to be a completely separate device, when that is not usually the case. The table below lists the most common types of servers that are implemented on a network. Server Types TypeDescription File server Stores network users' data files Print server Manages the printers that are connected to the network and the printing of user documents on the network printers Communicat ions server Handles many common communications functions for the network, such as e- mail, fax, or Internet services Application server Shares network-enabled versions of common application software and eliminates the need for software to be installed on each workstation Database server Manages a common database for the network, handling all data storage, database management, and requests for data