A relational database stores data in separate tables instead of placing all data in one large table. It then allows Data Base Administrators (DBAs) to define relationships between these tables. These relationships enable DBAs to combine data from several tables for querying and reporting. This is accomplished through the use of keys, which are database fields used to uniquely identify specific records in a table. Relational database technology allows databases to be larger, faster, and more efficient. Dr. Edger F. (Ted) Codd first developed the concept of a relational database Read More

Installing the DNS Server Service There are a number of methods which you can use to install the DNS server service on your Windows server. Install the DNS server service on a stand-alone computer using the Add or Remove Program applet of Control Panel. Install DNS when you install the first domain controller for an Active Directory domain. Install DNS on an existing domain controller in an Active Directory domain. Before installing the DNS server service, it is recommended that you perform the following administrative tasks: Configure a static IP Read More

DVDs do not require frequent cleaning. In fact frequent cleaning may spoil the DVD. Hence it is best to clean the DVD when it is absolutely necessary. You can clean the DVD before storing it and when you notice contamination on its surface. You can also clean the DVD when you find that the readability is impaired. Use a Soft Cloth Use a soft cloth and a special cleaning solution for your DVDs. You should avoid using any kind of organic solvents. Also refrain from using harsh solvents like acetone Read More

On a day-to-day basis when you use your computer you have the ability to organize the information on your hard drive any way you want. One of the easiest methods of organizing your hard drive is by function. This way you use one partition for the operating system, one for your applications and one for the data you create. When you partition your hard drive what you are really doing is dividing it into isolated sections. So when you partition a drive, each partition will then act as an individual Read More

The VirtuSphere is essentially a hollow sphere that is fitted with sensors. Because of this, it is capable of providing a user with an immersive virtual reality experience. Inside the VirtuSphere, a user can move about in a virtual reality world by the simple act of walking as he normally would outside of the sphere. The VirtuSphere is mounted on a special platform that enables the sphere to move with the user's movements. Sensors inside this platform provide information on the speed and direction of the user, making it seem Read More

VLAN Hopping is one of the primary VLAN based attacks used by hackers to infiltrate network security. VLAN hopping is used to attack a network by sending packets to a port which is generally not accessible. VLAN hopping attacks are mainly conducted in the Dynamic Trunking Protocol and, in some cases; the attacks are targeted to the trunking encapsulation protocol (802.1q or ISL). The Dynamic Trunking Protocol is utilized for negotiating trunking on links between devices and the type of trunking encapsulation to be used. Types of VLAN Hopping Switch Read More

Facial recognition systems are computer programs that are used for automatically identifying a person. Research on this technology started in the mid 1960s. This technology works by using several facial features in a person's image and comparing these with existing images in the database. Facial recognitions systems are used as an additional and mass security measure and are comparable to the other biometric security systems available today such as retina scanners, fingerprint scanners, etc. The Technology behind Facial Recognition Systems The first important factor in facial recognition systems is its Read More

Understanding the Cisco Three-Layer Hierarchical Model Hierachical network design helps us to make networks more reliable and predictable. Level by level design help to understand networking factions easily like, we can use tools like access lists at specific level and can avoid them from others. Cisco layer model consist of the following three layers. The Core layer The Distribution layer The Access layer Each layer plays a role and specific responsibilities are assigned to these three logical layers. These layers are same like the network layers of OSI reference model. Read More

The former method discussed is quite inefficient. Let us see if a more efficient method to compute path can be produced. Let us define the matrix path k such that path k [i][j] is true if and only if there is a path from node i to node j that does not pass through any nodes numbered higher than k (except, possibly, for i and j themselves). How can the value of path k+ J [i][j] be obtained from path k? Clearly for any i and j such that path Read More

Remote Administration Overview When it comes to administering servers and desktops in secure organizations or large organizations, administrators would typically be found performing remote administration. This basically means that administrators would be using the Microsoft Management Console snap-ins or support tools remotely, to administer servers. For instance, through the Microsoft Management Console snap-ins, you have the option of connecting to remote systems. In fact, most administrative tasks which you can perform locally, you can perform remotely. With the introduction of Windows Server 2003, came increased support for remote administration. This Read More