Computer Networking

Computer networking is a linking of the network devices and computers with each other to provide the data communications and sharing the network resources such as printer, scanner, modem, CD/DVD and internet access. A computer network can be interconnected with the UTP/STP cables, coaxial cables, fiber optics and wirelessly through the radio waves. Today, no business can work effectively without the data communications within the organization. A network can be designed by different layouts known as topologies. The common topologies include star, hub, mesh, hybrid and ring. Star topology is the most common topology in Ethernet based local area network. There are specialized rules and standards and based on these standards, the devices communicate with each other. One of these specialized standards and agree up ways is known as protocols. TCP/IP is the protocol suite that contains the multiple communication protocols such as TCP, IP, SMTP, FTP, DHCP, LDAP, PPP, Telnet and many others. TCP/IP works together and it is the most common communication protocol for the LAN, WAN and internet. The communications on the internet is based on the IP addresses, which is a part of the TCP/IP stack. No computer on the internet or in the LAN/MAN/WAN can communicate without a unique IP address. Networking and data communications provides the flexibility, easy of work and communications with each other and today every kind of business in the world, which involves more than one computer, require a computer network. A network can be setup by using the following things. Computer with Windows/Linux operating system installed. Every computer requires a unique LAN card, which should be properly installed and configured. Ethernet cable with the RJ-45 connectors at both ends. A Router/Switch or hub. The other devices are bridges, transceivers, terminal servers and gateways and they can be setup according to your requirements. There are three main types of the computer network i.e. LAN, MAN, WAN, CAN, GAN and PAN and each network either be a peer to peer or client server network. In a client/server network model, a centralized domain controller is used to control all the computer network. It provides the services to the clients like logon authentication, printer access, scanner access, centralized data storage, user management, resources management, DHCP, DNS, FTP and internet access. To communicate with the other computer, each computer should support the same protocol and the TCP/IP is the most commonly used protocol in a computer network. Internetwork is a type of computer network that connects the two or more different networks. There are three main types of the internetwork i.e. intranet, extranet and internet.

Network Security

Security is an important ingredient for computer network (LAN, WAN, MAN) maintenance. It is the job of the network administrator to save your online presence from malicious attacks of hackers, viruses, and Trojans through a reliable security system. Whether you are working in a home or enterprise network, try to secure it by implementing advanced and protective security strategies. Network security is the study of implementing different techniques to save your business and home computers from malicious hacking and virus’s attacks. Here is a brief overview of some common network attacks. Denial of services Denial of service strategy is applied to a specific web server so that it becomes unavailable for internet users. Hackers usually send too many requests for general information. In this respect, it makes use of web server resources that can either slow down or crash the server. BlackHat Hacking Network hackers with technical knowledge can easily access any unsecured network. Common network damage involves configuration change in network equipment like router servers. They usually make these devices unavailable for internet users. Consequently such types of problems take network administrators a great deal of time and effort to fix the problems. It results in a loss of money because productivity is reduced drastically. Some hackers even get access to private information like patient/client record, or credit card details. These damages can cost thousands of dollars to your company. At home, these network hackers try to steal your sensitive information like credit cards and other scanned documents. Here, I would like to suggest some essential network security principles that every computer user must install on their network servers and systems. Firewall It is called a set of principles to deny or allow access to the network. It is usually installed inside the network router. The basic purpose of using a router is to get access to the network. Firewall works on a set of rules based on closing and opening of ports associated to protocol. Whenever any internet user stops using a network protocol for communication, the router closes the port of this protocol. Access Control Lists Access control list works like a firewall. Its basic function is to filter network traffic based on various metrics included in IP packets. Access control list is configured to test the secure status of each packet (data segmentation on OSI layers) and IP address destination. It also checks the destination and source port number. Usually, a network administrator writes an access control list and specifies the range of IP addresses communicating to each other and the protocols used in this communication session. In such situations, it becomes quite tough for network hackers to get access to a network in which the router is blocking unauthorized access. Encryption It is an easy and simple algorithm used to convert information into an unreadable format. Only a person who has access to the specific algorithm can decrypt it. Always try to send sensitive information through these encryption techniques. WEP / WPA These days, wireless networks are widely used due to their portability features. It is also necessary to protect your wireless network from hackers. Recent research indicates that a new version of wireless network called WPA2 is more secure than its previous version (WEP). When you are setting your wireless network, you must set your security to WPA2.