IT for Decision Makers
NETWORKING AND SECURITY ISSUES
Handout 1 Overview
Many organizations have invested vast amount of money in computer networks, only to find out that although it is providing means of improving the efficiency and productivity of the organization but it also exposes the Organization to possible attacks and threats. Such attacks have been the most challenging issue for most network administrators and a worrying topic for administrators.
Organizations need to share services resources and information but they still need to protect these from people who should not have access to them, while at the same time making those resources available to ...view middle of the document...
A similar network on a larger scale is sometimes referred to as a WAN (Wide Area Network), or in some cases more specifically, a MAN (Metropolitan Area Network) if it is confined to a single metropolitan area.
The term LAN is most often used to refer to networks created out of a certain class of networking equipment which is tailored to communication over a short distance. This is in contrast to networks, which happen to span short distances, yet are constructed using "WAN" equipment (i.e., equipment capable of transmitting long distances). LAN-style networking equipment typically transmits data at a higher rate than WAN-style equipment: the equipment's design takes advantage of the short distance to supply a high transmission-rate at a relatively low cost.
If you are familiar with network access using a modem and ordinary telephone line, note that both LAN and WAN equipment typically offers faster data transfer than even the fastest ordinary modem/phone-line access, LAN transfers being on the order of a million times faster. This means graphics that are loaded through the network can be displayed significantly faster, and that there are things that it is practical to do on a LAN that you would never do with a modem: for example, you might set up your computer to load your word processing application through the LAN rather than from hard disk; the time you have to wait while it loads would be similar (a few seconds) in either case. In contrast, loading such an application through a modem would require minutes or hours.
A typical use of a LAN is to tie together personal computers in an office in such a way that they can all use a single printer and a file server (briefly, a file server is a computer set up so that other computers can access its hard disk as if it were their own). LANs are also used to transmit e-mail between personal computers in an office, or to attach all the personal computers in the office to a WAN or to the Internet.
There is some variation in the way the term LAN is used:
It is used to refer to a file server and printer, and often the personal computers that are tied to them. People refer to saving their files on the LAN, or on the PC LAN.
It is used more specifically to refer to the data communications wiring and equipment that ties the personal computers to the file server and the printer.
One of the terms associated with most Networks is Ethernet, the most common type in use today. Ethernet is an example of what is called a LAN technology, or in the more specific sense of the word LAN, one of several types of LANs. Some other types of LANs are Token Ring, FDDI, and Fast Ethernet.
What is the Internet?
The Internet is the world's largest network of networks . When you want to access the resources offered by the Internet, you don't really connect to the Internet; you connect to a network that is eventually connected to the Internet backbone, a network of extremely fast (and incredibly...