14 - Security considerations

Abstract

This chapter focuses on the security issues related to a network. As the use of the Internet, intranets, and extranets has grown, so has the need for security. The TCP/IP protocols and network technologies are inherently designed to be open in order to allow interoperability. Therefore, unless proper precautions are taken, data can readily be intercepted and altered, often without either the sending or the receiving party being aware of the security breach. Dedicated links between the parties in a communication are often not established in advance; therefore it is easy for one party to impersonate another party. Threat experienced by intranets and extranets usually include, unauthorized access by contractors or visitors to a company's computer system; access by authorized users (employees or suppliers) to unauthorized databases; confidential information might be intercepted as it is being sent to an authorized user; electronic mail can be intercepted in transit; or hackers can break into the mail server. This chapter elaborates the security considerations for a network and also defines the ways of controlling access to a network.