MODULE TITLE: ADVANCED NETWORK SECURITY PRINCIPLES

Module Title: Advanced Network Security Principles



Module Title: Advanced Network Security Principles

 Since the last two decades there has been an overwhelming increase in the number of organizations that rely on data communication networks for their daily business communications, resource sharing, database information retrieval so on and so forth. Previously most computers were centralized and managed in data centres. Computers were kept in locked rooms and links outside a site were unusual. Computer security threats were rare, and were basically concerned with insiders. These threats were well understood and standard techniques were used to deal them. The scenario has changed and now systems are connected to the Internet. The Internet is a network of networks and has no boundaries whatsoever. The Internet provides these organizations with a world of business opportunities.

 Information on the Internet can be accessed from anywhere in the world, unfortunately it has also allowed for the “proliferation of malicious information”. It does not take long for an expert programmer to break into a system. The value of the data stored on most organizations' networks and the value provided by the application systems in use far exceeds the cost of the networks themselves. Network security has become of the most important issues for these business organizations and aims at protecting the organizations' data and application software.

 A ``network'' has been defined as ``any set of interlinking lines resembling a net, a network of roads an interconnected system, a network of alliances.'' This definition suits our purpose well: a computer network is simply a system of interconnected computers and peripherals.

Essentially there are three basic hardware components of a data communication network.

 

The server or the host computer houses all the data and the software that is to be accessed by the clients.

A client can be referred to as an input/output hardware device that lies at the other end of the communication circuit. It enables the user to have an access to the network and the data and software on the server.

The circuit is the route or the medium through which the message travels. Nowadays the fibre optic cable and wireless transmission are becoming increasingly common.

 Writer. Business data communication and networking.

 Classification of Networks

Classification of Networks by: 

-Geographic Coverage (LANs, MANs, WANs, GANs)

-Method of Accessing the Network (Demand, Polled, Multiaccess)

-Architecture

 Networks for small and growing businesses generally come in two types: 

A peer-to-peer network lacks a central server. There is a set of computers, which are linked together by a cable. Each computer is an equal, or "peer," of the others, and has the ability to share the files and peripherals of other computers that are connected to the network. This type of network is essentially designed for a very limited number of users (five or less) in a business organisation. Some of the benefits of a peer-to-peer network are low-cost and easy-to-install solution. If anyone of the user turns of its workstation the other users are not able to access this particular user's information and ...