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admin on Tuesday, March 9th, 2010 |
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A computer network is a collection of two or more computers with communication between them through a medium. The communication medium can be through radio waves, wires, infrared, optical fibers etc.
Computer network is an integral part of our daily lives, with the most important reason being that of communication. The use of computer networking is to share resources like fax machines, printers, modems, files etc., and its other uses are database server, computer server, email, chat, internet etc. The computer to which the resources are attached is called the server and the other computers that access the resource are called clients. In peer-to-peer computer networks there are no servers.
The sharing of fax machines, printers, and modems amongst many computers and users reduce the operational cost. A database on a computer network is a very important application as it stores and runs many important data and jobs. Emails and chats can be used for instantaneous communication and sending of files on a computer network.
The computer networks are classified, depending upon the size, as Local Area Networks (LAN), Wide Area Networks (WAN), Metropolitan Area Networks (MAN) and Personal Area Networks (PAN). The topology (topology is the way the computer networks and network resources are connected) of the networking can be classified as Bus Network, Ring Network and Star Network.
The networking hardware basically consists of wiring, network cards and a hub. Computer network cards are required so that one computer can understand what the other computer is “talking”. Network… Read the rest
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admin on Thursday, October 15th, 2009 |
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The Computer is a very complicated device we use for our every day comfort and the importance of some of its numerical aspects is sometimes neglected. For example: a different number is given to each computer when its user goes online or when it is part of a network. This number is the IP address and knowing about it is like knowing where you live?
What’s my IP and what do its numbers stand for?
IP stands for Internet Protocol and the address is formed from 4 numbers separated by periods. The IP address format is a 32 bit numeric one and each number can be from 0 to 255. The IP address consists of two parts: first one represent the network number and it is similar for more than one user (like the number of a street) and second represents the host name which is different for each user (like the house number). To increase the number of available IP addresses within big networks with a lot of users or small networks with few hosts, the address is divided into 4 classes (A, B, C, and D)
Having an IP address it’s like having a last name in a network. To identify a computer in a network (LAN-local area network, WAN-wide area network or on the Internet) it has to have an IP address. This number is similar to a phone number or to a zip code. It is unique and without it the device or computer can… Read the rest
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admin on Thursday, July 16th, 2009 |
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Web and FTP Servers
Every network that has an internet connection is at risk of being compromised. Whilst there are several steps that you can take to secure your LAN, the only real solution is to close your LAN to incoming traffic, and restrict outgoing traffic.
However some services such as web or FTP servers require incoming connections. If you require these services you will need to consider whether it is essential that these servers are part of the LAN, or whether they can be placed in a physically separate network known as a DMZ (or demilitarised zone if you prefer its proper name). Ideally all servers in the DMZ will be stand alone servers, with unique logons and passwords for each server. If you require a backup server for machines within the DMZ then you should acquire a dedicated machine and keep the backup solution separate from the LAN backup solution.
The DMZ will come directly off the firewall, which means that there are two routes in and out of the DMZ, traffic to and from the internet, and traffic to and from the LAN. Traffic between the DMZ and your LAN would be treated totally separately to traffic between your DMZ and the Internet. Incoming traffic from the internet would be routed directly to your DMZ.
Therefore if any hacker where to compromise a machine within the DMZ, then the only network they would have access to would be the DMZ. The hacker would have little or… Read the rest
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admin on Sunday, April 12th, 2009 |
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As far as I’m concerned, wireless networks would have to rank as one of the best inventions in history. They really are the best thing since sliced bread. I mean, really, bread is easy enough to cut yourself, but have you ever tried to wire up a network? Its a lot of hard yakka as many would say.
WiFi is the wireless way to handle networking. It is also known as 802.11 networking and wireless networking. The big advantage of WiFi is its simplicity. You can connect computers anywhere in your home or office without the need for wires. The computers connect to the network using radio signals, and computers can be up to 100 feet or so apart. So, in the spirit of spreading the word, I’m going to give you some great reasons why you need a wireless network.
Sharing Internet Access.
Wireless networking gives you a cheap and easy way to share one Internet connection between multiple computers, eliminating the need for more than one modem. You can even add new computers to your network simply by plugging in a wireless card and switching them on — they get an Internet connection straightaway! There aren’t many wired networks that can say that.
Sharing Files and Printers.
A wireless network gives you access to your files wherever you are in your home, and makes it easy to synchronise the data on a laptop with a home computer. It is much easier to send files between computers with a… Read the rest