Wednesday, December 3, 2008

Networks

Networks

Most people working in office with more than a couple of computers will be using some form of network. As networks become easier to setup and maintain more home users are also setting up networks to share resource such as disk space, printers, Internet connections and access to software.

A network is basically two or more computers connected through a cable or wire which share resources. Network software controls how the computers communicate.

There are dozens of different types of networks which are impossible to cover in an introduction article. This article focuses on home and small business networks using some version of the Window operating system.

To connect computers each of the computers needs a network card with a connection that allows a cable to be connected to it. Computers can be connected directly through a bi-directional cable or through an other piece of hardware called a hub. The hub then connects all the computers in your local network together. Both solutions cost about the same but a hub allows more than two computers to connect. A hub can also be used to connect two local area networks together to create a wide area network.

Some form of network software is required. This network protocol software is installed through the network preferences. NetBIOS was commonly used though recently a secure TCP/IP protocol has been developed. The network protocol determines how computers become part of the network and how they are recognized. The network must have a name and you can use some creativity at this point. Each computer must also have a unique name that other computers on the network can access them with.

If all goes well this is all you need but often there will be a conflict that can be resolved by establishing exactly how the computer will communicate. To solve these types of conflict your network needs a set DNS server address and each computer in the network needs to be assigned a unique IP address. The addresses usually are in the range of 192.168.x.x where x means any number between 0 and 255. Once these numbers have been entered your network should be functioning with each computer able to see the other computers on the network.

You must also decide which resources you want to share. You may want to make a disk or folder available, a printer or tape backup system so that everyone can use it. You may also want to have parts of the network that are either not accessible or accessible only through a password. File and print sharing must be enable on the computer that will share it's resources or host computer and they determine how they are accessed by other computers or clients.

A computer with an Internet connection can also share that connection with other computers on the network but you should check with your ISP what their policy on sharing Internet connections is. Sharing an Internet connection also raises some serious security issues. Many cable high speed Internet connections use the Network Neighborhood settings to create the Internet connection and connecting your home or office network to this existing system can cause problems. Though you may want to allow a computer in another room of the house to access files or run programs on your computer you probably don't want the kid down the block to have that same access.

Security on networks begin with passwords. Everyone who wishes to access the network must logon with a username and password. If someone cancels the password challenge they will be able to access the files and programs on that individual computer but can't access any of the network resources. Specific passwords for important folders or disks can also be set or access to folders or disks can be forbidden.

Unlike server/client networks where the server must be running before the computers can communicate the peer-to-peer network that comes packaged with Windows allow any computers that are turned on to communicate with other. Other computers in the network become accessible as user turn them on.

Networks can also be open to remote secure access through a virtual private network. A VPN allows a computer to connect to a computer or network through the Internet.

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