HVAC Control in the New Millennium.pdf - HVAC.Amickracing

Computer Networks and Securitywork with undesired network packets is one technique that is used.Another technique is to leave false information about the status of networkresources.Application and Trojan Horse AttacksApplication attacks use some weakness in the software that isfound on servers, including FTP. This allows the attacker to gain accesswith the permission of the account running the application.Trojan horse program attacks use a program that the attacker substitutesfor another program. The substitute program can furnish thefunctions of the normal program. But, it also may monitor log-in attemptsand seize user account and password information.One type of Trojan horse program displays a screen, banner, orprompt that looks like a valid log-in sequence. The program processesthe information that the user types in and e-mails it to the attacker.Securing the NetworkNetwork security can include firewalls, proxy servers and dataencryption. Proxy servers and firewalls act as traffic cops. They regulatewho gets in and out of the network.A firewall monitors the traffic crossing network perimeters andsets restrictions according to the security policy. Perimeter routers canalso be used. These can be located at a network boundary. Firewallscommonly separate internal and external networks. The firewall serveracts as the gateway for all communications between trusted networksand untrusted and unknown networks.The least secure network is the outermost perimeter network of thesystem (Figure 7-6). This area of the network is the easiest area to gainaccess to, making it the most frequently attacked.PasswordsThe shorter the password, the easier it is to guess and test. Passwordsshould be at least eight characters long. The maximum number of©2001 by The Fairmont Press, Inc. All rights reserved.