A computer network consists of two or more computers connected by communications media in order to share resources, communi- cate, and centralize management of resources.
A LAN is limited geographically to a room, a floor of a building, an entire building, or a campus that is all connected with a common network technology, usually at the fastest speeds (10 Mbps, 100 Mbps, 1 Gbps, or 10 Gbps).
A MAN is a network that covers a metro- politan area, usually connected by a high- speed fiber-optic cable, and that runs at speeds measured in gigabits per second.
A WAN is two or more networks connected over long distances using phone lines or satellite communications with speeds normal- ly ranging from thousands of bits per second to millions of bits per second.
Network software components include network operating systems, device drivers, services, and protocols.
Network communication protocols suites include TCP/IP (by far the most common), NetBEUI (very rarely used today), Apple's AppleTalk (replaced by TCP/IP), and Novell's IPX/SPX (also being replace by TCP/IP).
UNIX runs on a variety of platforms and is offered by vendors such as IBM, Compaq, Caldera, Hewlett-Packard, and Sun. It has long been the server of choice for hosting network infrastructure services. It remains the top choice for servers that host large databases shared by hundreds or thousands of users, especially in industries such as insurance, medicine, banking, and manufacturing.
The many versions of Linux, distributed by vendors such as Red Hat, Novell, Hewlett-Packard, the Gentoo Foundation, and MandrakeSoft SA, are growing in popularity within organizations, competing with all other server operating system in many arenas.
Novell’s NetWare server OS dominated the LAN server market in the 1980s, but declined in the 1990s, although Novell introduced Novell Directory Services (NDS) in 1994, years ahead of Microsoft’s competing Active Directory.
Currently, NetWare is just one server product line offered by Novell. They have added two Linux Server products: SuSE Enterprise, for a broad range of computers up to mainframes, and SuSE Standard, for basic small business or departmental servers.
Centralized data backup has long been an important network service, and several vendors sell centralized backup systems that use a dedicated backup server, large tape archiving systems, and specialized client software.
Planning for effective use of user accounts and group accounts is complex but worthwhile.
After users and groups have been created, create shares to give users access to the resources they need. If a share is on an NTFS volume, set NTFS permissions on the under-lying files and folders before creating the share.