VNC - Virtual Network Computing Basics

Sharan R >> , , , , ,

VNC Basics

Virtual Network Computing, or "VNC," is software used to connect remotely to a computer system. This allows a user to see and control one computer from multiple locations. Because this control is transmitted over the Internet, the computer can be viewed from anywhere in the world.

VNC software is fairly uncomplicated and easy to use. Many operating systems, including Microsoft Windows, already include simple VNC programs. These applications allow users to connect remotely and operate another computer loaded with the same software.

VNCs allow computers to become remotely sharable. This means that several different users, each in separate locations, can view a computer desktop at the same time. VNC software makes training, monitoring and troubleshooting easy by making remote access flexible.

VNC Interface

Most VNC systems are controlled from a simple graphic user interface. Once the software has been installed on a remote computer, it can be accessed from any location. A server constantly monitors inputs and outputs from one computer, and updates them to the second location.

The interface for most VNCs can operate from any operating system, such as Windows, Macintosh, or Unix. Because information is transmitted over the Internet, the system eliminates many of the traditional cross-platform problems. Just as a website can be viewed on many different operating systems, so can VNC control operate from many different computer types. While "VNC" is a generic term for this type of software, many brands of the software exist, with packages available for all major operating systems.

The connection used to interface data is protected by a password. This prevents unauthorized users from controlling a remote computer. Once the connection is established, information begins to be exchanged. Details on mouse location, keyboard entry, and screen updates are fed over the secure connection, keeping the computers synchronized.

VNC Uses

VNC software began as a way to monitor and troubleshoot systems remotely, and this feature remains a common use. Computer technicians can provide tech support using VNC without being physically present. If a user is having a problem installing software, for example, a support professional can connect to her computer, see the problem, and talk the user through the solution.

Use of VNC software has also expanded to other areas. Remote work has become an increasingly popular option. VNC allows workers to access and control software without being in the office. For instance, using VNC, a programmer in India can easily control a desktop computer in California, collaborating with colleagues and working on a project remotely.

Overview

VNC consists of two components. A server, which runs on the computer you want to remotely access, and a viewer, which runs on the computer you are sitting in front of. There are two important features of VNC:
  • The server and the viewer may be on different machines and on types of computer. The protocol which connects the server and viewer is simple, open, and platform independent.
  • No state is stored at the viewer. Breaking the viewer's connection to the server and then reconnecting will not result in any loss of data. Because the connection can be remade from somewhere else, you have easy mobility.
So to get started with VNC you need to run a server, and then connect to it with a viewer. First of all, you have to download and install the software on the platforms you want to use. The screenshots on this page refer to VNC Free Edition 4.1, but the general concepts apply to all versions of Free Edition and Enterprise Edition.

Networking

VNC software requires a TCP/IP connection between the server and the viewer. This is the standard networking protocol on LANs, WANs, broadband and dialup ISP. Each computer has a unique IP address and may also have a name in the DNS. You will need to know the IP address or name of the server when you connect a viewer to it.
Sometimes the IP address is fixed, and sometimes it is issued to you dynamically by your ISP. If it is allocated dynamically, you might consider using a third party DNS management service. Try typing "dynamic dns management service" into a google.

Running a Windows server

Installing the Windows server, WinVNC, should create a RealVNC group in your Start... menu. Run the VNC server.

If this is the first time you've used a VNC server on this machine you'll be prompted to set a password, which you'll need when you connect to the machine from a remote location. A small icon will appear in the system tray, and by right-clicking on this you can control most aspects of the server.

winvnc4_traymenu

The IP address of the computer running the VNC server can be found by hovering over the tray icon in the system tray. Unless this computer has a DNS name, you will need to specify this number to the viewer when you connect.

winvnc4_ipaddr

You can now go to another machine and connect a viewer to the server.

Running a Unix server

To X applications, a VNC server appears just like the standard X display you sit in front of, but without a physical screen attached. The applications don't know this, they just carry on running whether or not a viewer is connected. You can start a new VNC server on a Unix machine by typing:
 
vncserver

If you haven't run a VNC server before you will be prompted for a password, which you will need to use when connecting to this server. All your servers on the same Unix machine will use the same password, and you can change it at a later date using
 
vncpasswd

With a normal X system, the main X display of a workstation called ’snoopy’ is usually snoopy:0. You can also run as many VNC servers on a Unix machine as you like, and they will appear as snoopy:1, snoopy:2 etc, as if they were just additional displays. Normally vncserver will choose the first available display number and tell you what it is, but you can specify a display number if you always wish to use the same one:
vncserver :2

You can cause applications to use a VNC server rather than the normal X display them by setting the DISPLAY environment variable to the VNC server you want, or by starting the application with the -display option.

For example:
xterm -display snoopy:2 &
You can kill a Unix VNC server using, for example:
vncserver -kill :2

Full instructions for installing and running VNC server for Unix can be found in the RealVNC Site documentation.
Nothing will appear immediately as a result of starting a Unix VNC server. To see anything you need to connect a viewer to the server, see below.

Running a viewer

You can run the Windows viewer the RealVNC group on the Start... menu.
winvncviewer4_startmenu

In this case, you will be prompted for the host name (VNC server name) and display number:


winvncviewer4_display

Enter it and click OK, and you will be prompted for your password, after which you should see the remote display. If you are connecting to a Windows or Mac server, the display number will be 0 unless you have explicitly changed it, and can be omitted.

You can run the viewer on Unix and Windows by typing at the command line:
vncviewer snoopy:2

You need to specify the name of the VNC server and the number of the desktop. If, for example, you have started a server as display 2 on a machine called 'snoopy'. Remember that if you are connecting to a Windows or Mac server, the display number will be 0 unless you have explicitly changed it, and can be omitted.

If the machine running the server does not have a DNS entry, you probably won't be able to use the name and will have to replace snoopy with its IP address, for example something that looks like 123.456.78.9.

Using a web browser as a viewer

The VNC servers also contain a small web server. If you connect to this with a web browser, you can download the Java version of the viewer, and use this to view the server. You can then see your desktop from any Java-capable browser, unless you are using a proxy to connect to the web. The server listens for HTTP connections on port 5800+display number. So to view display 2 on machine 'snoopy', you would point your web browser at:

http://snoopy:5802/

The applet will prompt you for your password, and should then display the desktop.
 


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How to Safely Remove Linux OS from Dual boot and restoring your MBR ?

Sharan R >> , ,
This tutorial explains how to remove linux operating system safely from your Dual boot systems(i.e. windows and linux both are installed on that computer).

Linux operating systems are pretty good. and because they are free and eaisly available we always want to try a new one. But at the sametime we dont want give up our favorite windows operating systems. so we choose to have a dual boot system where we can switch to any of the OS easily. But when we want to remove Linux OS and return to window we come across a problem that windows cant find MBR (Master Boot Record). To overcome this problem we have to restore MBR. To do this just follow these steps:

First of all you need to know where your Linux OS is installed to,i.e. what drive it is currently living on?
Then next thing is to restore that partition used by Linux to windows. To do this:

    1.Click Start > Control Panel > Classic View > Administrative Tools > Computer Management.
    2.Click Storage > Disk Management.
    3.Select the Linux partition, right click and select Delete volume option to delete linux and grub.
Once you have followed this through, you will now have free space.
Once you have formatted the drive, you need to reformat it to your required file system type. either Fat32 or NTFS.
Now the important part is coming up...!!!

Fixing your Master Boot Record to make Windows Bootable again.

    1.Boot up with the Windows CD.
    2.Restore your Master Boot Record (MBR) by using the following command:
        a.If using a Windows 98 CD, boot into command prompt and enter: fdisk /MBR
        b.If using Windows 2000, XP, 2003 CD, enter into “Recovery Console” by pressing “R”, and
          enter: fixmbr
       c.If using Windows Vista, Server 2008, Windows 7 CD, click on “Repair Computer” link, then click on “Command Prompt”.

Navigate to your CD drive by using cd  command and
enter: bootsect /nt60 SYS /mbr
 3.Exit from the command prompt and press Enter or restart your computer.

There will be no Grub shown and you will directly boot into Windows. This is how you will return to a normal window operating system from a dual boot system.

Thanks...!!!
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Cloud Computing - Overview

Sharan R >> , ,

An Overview
Cloud computing is a computing paradigm, where a large pool of systems are connected in private or public networks, to provide dynamically scalable infrastructure for application, data and file storage. With the advent of this technology, the cost of computation, application hosting, content storage and delivery is reduced significantly.
Cloud computing is a practical approach to experience direct cost benefits and it has the potential to transform a data center from a capital-intensive set up to a variable priced environment.
The idea of cloud computing is based on a very fundamental principal of „reusability of IT capabilities'. The difference that cloud computing brings compared to traditional concepts of “grid computing”, “distributed computing”, “utility computing”, or “autonomic computing” is to broaden horizons across
organizational boundaries.
Forrester defines cloud computing as:
“A pool of abstracted, highly scalable, and managed compute infrastructure capable of hosting end-customer applications and billed by consumption.” 
Figure 1: Conceptual view of cloud computing

Cloud Computing Models
Cloud Providers offer services that can be grouped into three categories.
1              Software as a Service (SaaS): In this model, a complete application is offered to the customer, as a service on demand. A single instance of the service runs on the cloud & multiple end users are serviced. On the customers‟ side, there is no need for upfront investment in servers or software licenses, while for the provider, the costs are lowered, since only a single application needs to be hosted & maintained. Today SaaS is offered by companies such as Google, Salesforce, Microsoft, Zoho, etc.
2              Platform as a Service (Paas): Here, a layer of software, or development environment is encapsulated & offered as a service, upon which other higher levels of service can be built. The

customer has the freedom to build his own applications, which run on the provider‟s
infrastructure. To meet manageability and scalability requirements of the applications, PaaS providers offer a predefined combination of OS and application servers, such as LAMP platform (Linux, Apache, MySql and PHP), restricted J2EE, Ruby etc. Google‟s App Engine, Force.com, etc are some of the popular PaaS examples.
3. Infrastructure as a Service (Iaas): IaaS provides basic storage and computing capabilities as standardized services over the network. Servers, storage systems, networking equipment, data centre space etc. are pooled and made available to handle workloads. The customer would typically deploy his own software on the infrastructure. Some common examples are Amazon, GoGrid, 3 Tera, etc. 

Figure 2: Cloud models

Understanding Public and Private Clouds
Enterprises can choose to deploy applications on Public, Private or Hybrid clouds. Cloud Integrators can play a vital part in determining the right cloud path for each organization.
Public Cloud
Public clouds are owned and operated by third parties; they deliver superior economies of scale to customers, as the infrastructure costs are spread among a mix of users, giving each individual client an attractive low-cost, “Pay-as-you-go” model. All customers share the same infrastructure pool with limited configuration, security protections, and availability variances. These are managed and supported by the cloud provider. One of the advantages of a Public cloud is that they may be larger than an enterprises cloud, thus providing the ability to scale seamlessly, on demand.
Private Cloud
Private clouds are built exclusively for a single enterprise. They aim to address concerns on data security and offer greater control, which is typically lacking in a public cloud. There are two variations to a private cloud:
-On-premise Private Cloud: On-premise private clouds, also known as internal clouds are hosted within one‟s own data center. This model provides a more standardized process and protection, but is limited in aspects of size and scalability. IT departments would also need to incur the capital and operational costs for the physical resources. This is best suited for applications which require complete control and configurability of the infrastructure and security.
-Externally hosted Private Cloud: This type of private cloud is hosted externally with a cloud provider, where the provider facilitates an exclusive cloud environment with full guarantee of privacy. This is best suited for enterprises that don‟t prefer a public cloud due to sharing of physical resources.
Hybrid Cloud
Hybrid Clouds combine both public and private cloud models. With a Hybrid Cloud, service providers can utilize 3rd party Cloud Providers in a full or partial manner thus increasing the flexibility of computing. The Hybrid cloud environment is capable of providing on-demand, externally provisioned scale. The ability to augment a private cloud with the resources of a public cloud can be used to manage any unexpected surges in workload.

Cloud Computing Benefits
Enterprises would need to align their applications, so as to exploit the architecture models that Cloud Computing offers. Some of the typical benefits are listed below:
1. Reduced Cost
There are a number of reasons to attribute Cloud technology with lower costs. The billing model is pay as per usage; the infrastructure is not purchased thus lowering maintenance. Initial expense and recurring expenses are much lower than traditional computing.
2. Increased Storage
With the massive Infrastructure that is offered by Cloud providers today, storage & maintenance of large volumes of data is a reality. Sudden workload spikes are also managed effectively & efficiently, since the cloud can scale dynamically.
3. Flexibility
This is an extremely important characteristic. With enterprises having to adapt, even more rapidly, to changing business conditions, speed to deliver is critical. Cloud computing stresses on getting applications to market very quickly, by using the most appropriate building blocks necessary for deployment.

Cloud Computing Challenges
Despite its growing influence, concerns regarding cloud computing still remain. In our opinion, the benefits outweigh the drawbacks and the model is worth exploring. Some common challenges are:
1. Data Protection
Data Security is a crucial element that warrants scrutiny. Enterprises are reluctant to buy an assurance of business data security from vendors. They fear losing data to competition and the data confidentiality of consumers. In many instances, the actual storage location is not disclosed, adding onto the security concerns of enterprises. In the existing models, firewalls across data centers (owned by enterprises) protect this sensitive information. In the cloud model, Service providers are responsible for maintaining data security and enterprises would have to rely on them.

2. Data Recovery and Availability
All business applications have Service level agreements that are stringently followed. Operational teams play a key role in management of service level agreements and runtime governance of applications. In production environments, operational teams support
·         Appropriate clustering and Fail over
·         Data Replication
·         System monitoring (Transactions monitoring, logs monitoring and others)
·         Maintenance (Runtime Governance)
·         Disaster recovery
·         Capacity and performance management

If, any of the above mentioned services is under-served by a cloud provider, the damage & impact could be severe.

3. Management Capabilities
Despite there being multiple cloud providers, the management of platform and infrastructure is still in its infancy. Features like „Auto-scaling‟ for example, are a crucial requirement for many enterprises. There is huge potential to improve on the scalability and load balancing features provided today.
4. Regulatory and Compliance Restrictions
In some of the European countries, Government regulations do not allow customer's personal information and other sensitive information to be physically located outside the state or country. In order to meet such requirements, cloud providers need to setup a data center or a storage site exclusively within the country to comply with regulations. Having such an infrastructure may not always be feasible and is a big challenge for cloud providers.
With cloud computing, the action moves to the interface — that is, to the interface between service suppliers and multiple groups of service consumers. Cloud services will demand expertise in distributed services, procurement, risk assessment and service negotiation — areas that many enterprises are only modestly equipped to handle.
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How to set up your home wireless network

Sharan R >> , ,
You can use a wireless network (WLAN) to share Internet access, files, printers, game consoles, and other devices among all the computers in your home. After you’ve completed the initial wireless router setup and added your computers and devices to the network, you can use your home network to surf the web or to play online games—whether you're sitting in your living room or relaxing in your backyard.

It's easier than ever to set up a wireless network, especially now that Internet access and routers (like Linksys wireless routers and D-link wireless routers) have become widely available.
Man with a laptop in a hammock

What you’ll need to set up your wireless network

  • An operating system that supports wireless networking
    The Windows 7 operating system fully supports wireless networking. For Windows Vista users, we recommend installing Windows Vista Service Pack 2 before setting up your wireless network. For Windows XP users, we recommend installing Windows XP Service Pack 3. Use Windows Update to check whether you need the service pack and to install it. Click the Start button, click All Programs, click Windows Update, and then click Check for updates. Although the service packs for Windows Vista and Windows XP are not required for wireless networking, they can make things much easier and can help protect you against hackers, worms, and other Internet intruders.
  • A broadband (DSL or cable) Internet connection
    To set up a wireless network, you need a broadband or high-speed Internet connection (not a dial-up connection) provided by an Internet service provider (ISP), usually for a monthly fee. Two common broadband technologies are Digital Subscriber Line (DSL) and cable technology. These require a DSL modem or a cable modem (often provided by your ISP). After you have an ISP and a modem, you're ready to connect to the Internet.

    Set up a new connection to the Internet:
  • A wireless router, a DSL modem, or a cable modem with built-in wireless networking support
    The router converts the signals coming across your Internet connection into a wireless broadcast, sort of like a cordless phone base station. Newer DSL and cable modems come with integrated wireless networking capability and are called modem routers. If the modem router you received or purchased from your ISP already has wireless capability built in, you do not need to purchase a separate wireless router. Just follow the instructions provided by your ISP for activating your wireless connection.

    If you do need to purchase a wireless router, be sure that you buy a wireless router and not a wireless access point. The Linksys router is a popular router for wireless networks because it’s simple to set up. There are many routers to choose from, for example:





    Picture of a Linksys wireless routerPicture of a D-Link wireless routerPicture of a Cisco wireless routerPicture of an ASUS wireless router
    Linksys wireless        D-Link wireless       Cisco wireless        ASUS wireless routers
    While you're looking for a wireless router or other wireless equipment in stores or on the Internet, you might notice that you can choose equipment that supports four different wireless networking technologies: 802.11a, 802.11b, 802.11g, and 802.11n. We recommend 802.11g (Wireless-G) or 802.11n (Wireless-N) because they offer excellent performance and are compatible with almost everything.

    NOTE: If you do not want to buy a wireless router or if you want to connect computers or devices temporarily for a specific purpose, like sharing devices or games, you can set up a temporary wireless network without a router. This is called an ad hoc network.

    Set up an ad hoc network:
  • A computer with built-in wireless networking support or a wireless network adapter
    If you have a newer computer, you may already have built-in wireless capabilities. If this is the case, you don’t need a wireless network adapter. Here’s how to check whether your computer has wireless support installed:

    Windows 7 and Windows Vista


    • Click Start, click Control Panel, and then click Network and Internet. If you see any of these words listed, “Wireless,” “WLAN,” “Wi-Fi,” “802.11a,” “802.11b,” “802.11g,” or “802.11n,” your computer has wireless capability installed.

    Windows XP

    1. Click Start, right-click My Computer, and then click Properties
    2. In the System Properties window, click the Hardware tab.
    3. Near the top of this window, click the Device Manager button.
    4. In the Device Manager window, there is a list of hardware components which are installed on the computer. Press the Plus sign (+) to the left of the icon to open the Network adapters item in the list. The Network adapters section of the window expands to reveal a list of all network adapters installed on the computer.
    5. If you see any of these words in the list of installed network adapters, “Wireless,” “WLAN,” “Wi-Fi,” “802.11a,” “802.11b,” “802.11g,” or “802.11n,” your computer has wireless network support installed.

    If your desktop or laptop computer does not have built-in wireless support, you need to purchase a network adapter to wirelessly connect your computer to your wireless router. If you need an adapter for a desktop computer, buy a USB wireless network adapter. If you have a laptop, buy a PC card-based network adapter. Make sure that you have one adapter for every computer on your network.

    NOTE: To make setup easy, choose a network adapter made by the same vendor that made your wireless router. For example, if you find a good price on a Linksys router, choose a Linksys network adapter to go with it. To make shopping even easier, buy a bundle, such as those available from Linksys, Actiontec, D-Link, Netgear, Microsoft, and Buffalo. If you have a desktop computer, make sure that you have an available USB port where you can plug in the wireless network adapter. If you don't have any open USB ports, buy a USB hub to add additional ports.
  • A copy of your router setup instructions
    Before you begin setting up your wireless network, it’s a good idea to make sure that you have the copy of the setup instructions provided by the router manufacturer or your ISP. If you do not have a copy, visit the manufacturer’s website for get instructions on how to set up your router. All routers vary, and you may need to consult the instructions to set up your wireless network using your specific router.

1. Connect to the Internet

Make sure that your Internet connection and your DSL or cable modem are working. Your wireless network depends on this connection.

2. Connect your wireless router

These are the steps for connecting a stand-alone wireless router to your DSL modem or cable modem. If you have a modem router, follow your ISP’s instructions for connecting your network.
Since you'll be temporarily disconnected from the Internet, print these instructions before you go any further.
First, locate your cable modem or DSL modem and unplug it to turn it off.
Next, connect your wireless router to your modem. Your modem should stay connected directly to the Internet. Later, after you've hooked everything up, your computer will wirelessly connect to your router, and the router will send communications through your modem to the Internet.
Wireless router setup mapNext, connect your router to your modem:

Note: The instructions below apply to a Linksys wireless router. The ports on your router may be labeled differently, and the images may look different on your router. Check the documentation that came with your equipment for additional assistance. Or do a Bing search on “[your manufacturer/model] wireless router setup” to find images and instructions.
  • If you currently have your computer connected directly to your modem: Unplug the network cable from the back of your computer, and plug it into the port labeled Internet, WAN, or WLAN on the back of your router.
  • If you do not currently have a computer connected to the Internet: Plug one end of a network cable (included with your router) into your modem, and plug the other end of the network cable into the Internet, WAN, or WLAN port on your wireless router.
  • If you currently have your computer connected to a router: Unplug the network cable connected to the Internet, WAN, or WLAN port from your current router, and plug this end of the cable into the Internet, WAN, or WLAN port on your wireless router. Then, unplug any other network cables, and plug them into the available ports on your wireless router. You no longer need your original router, because your new wireless router replaces it.
Wireless modem lightsNext, plug in and turn on your cable or DSL modem. Wait a few minutes to give it time to connect to the Internet, and then plug in and turn on your wireless router. After a minute, the Internet, WAN, or WLAN light on your wireless router should light up, indicating that it has successfully connected to your modem.

3. Configure your wireless router

Wireless cablesUsing the network cable that came with your wireless router, you should temporarily connect your computer to one of the open network ports on your wireless router (any port that isn't labeled Internet, WAN, or WLAN). If you need to, turn your computer on. It should automatically connect to your router.

Next, open Internet Explorer and type in the URL or address to configure your router.

NOTE: Do this on the computer that you are using to set up your wireless network. The computer automatically links you to the router’s page. If you type the router’s URL on a different computer, typing the address in the navigation bar will not take you to your router’s configuration page.

On the router configuration page, you might be prompted for a password. The address and password you use varies depending on what type of router you have, so refer to the instructions included with your router or on the manufacturer’s website.

For quick reference, this table shows the default addresses, user names, and passwords for some common router manufacturers. If the address is not listed here, you can read the documentation that came with your router or go to the manufacturer's webpage to find it. There may be multiple website addresses you can use.

RouterAddressUsername   Password
3Comhttp://192.168.1.1       adminadmin
D-Linkhttp://192.168.0.1adminadmin
Linksyshttp://192.168.1.1adminadmin
Microsoft Broadbandhttp://192.168.2.1adminadmin
Netgearhttp://192.168.0.1adminpassword
Actiontechttp://192.168.0.1usernamepassword

Internet Explorer shows your router's configuration page, along with the modem IP address and other information. Most of the default settings should be fine, but you need to configure three things:
  • Your wireless network name, known as the SSID. This name identifies your network, and it appears in a list of available wireless networks. You should change the default SSID that your ISP provided and give your network a unique name that none of your neighbors are using. This helps you identify your network, and it can help keep your wireless network secure by preventing it from overlapping with other wireless networks that might be using the default SSID.
  • Wi-Fi Protected Access (WPA or WPA2), which can help protect your wireless network. It’s important to help secure your wireless network by setting up a network security key, which turns on encryption. With encryption, people can't connect to your network without the security key, and all information sent across your network is encrypted so that only computers with the key to decrypt the information can read it. This can help prevent attempts to access your network and files without your permission. Wi Fi Protected Access (WPA or WPA2) is the recommended wireless network encryption method. Wireless encryption (WEP) is not as secure. Windows 7, Windows Vista Service Pack 2, and Windows XP Service Pack 3 support WPA2.

    When you set up most routers (stand-alone routers and modem routers), you are asked to provide a pass phrase that the router uses to generate several keys. Make sure that your pass phrase is unique and long (you don't need to memorize it). Some routers and modem routers now come with a function called Quick Security Setup (or QSS) that automatically issues you a key when you press a button on the router.

    Be sure to keep a hard copy and a digital copy of your network security key and pass phrase, in case you lose or misplace them. You can recover a lost network key or reset it on your router, but these are complicated processes that are different for every router and they sometimes entail setting up your network again.
  • Your administrative password, which controls your wireless network. Just like any other password, it should not be a word that you can find in the dictionary, and it should be a combination of letters, numbers, and symbols. Be sure to save a hard copy and a digital copy of this password, too, because you'll need it if you ever have to change your router's settings.
The exact steps you follow to configure these settings will vary depending on the type of router you have. After each configuration setting, be sure to click Save Settings, Apply, or OK to save your changes.

Now, before connecting your computers and devices to the network, you should disconnect the wireless network cable from your computer.

4. Connect your computers, printers, and other devices to the wireless network

You can connect multiple computers, printers, and many other peripheral devices, such as an Xbox, Xbox 360, TV, cell phone, iTouch, or iPad, to your network. Before you connect them to your network, make sure that the computer or device you want to add has built-in wireless networking or a network adapter. Many newer devices have built-in wireless capability. If the computer or device you want to add does not have built-in wireless network support, plug the network adapter into your USB port and place the antenna on top of your computer (in the case of a desktop computer) or insert the network adapter into an empty PC card slot (in the case of a laptop). Windows automatically detects the new adapter and may prompt you to insert the CD that came with your adapter. The on-screen instructions guide you through the configuration process.
Use the following links to find step-by-step instructions for adding your specific computer or device to your network using your operating system. There are instructions for each operating system, and they show you how to automatically or manually add wired (Ethernet) or wireless computers and how to add computers running Windows 7, Windows Vista, or Windows XP. There are also instructions for adding printers and both wired and wireless devices.

5. Share files, printers, and more

Now that your computers and devices are connected, you can begin sharing files, printers, games, and much more. One of the top reasons for setting up a home network is to share a printer. Another is to share files. The steps for doing this, however, aren’t always obvious, so here are instructions to get you started:

Share a printer
Share files
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Types of Wireless Network Security methods

Sharan R >> , , , , ,
If you plan to have a wireless network, you should set it up so that only people you choose can access it. Here are a few options for wireless network security.

Wi‑Fi Protected Access (WPA)

WPA encrypts information, and it also checks to make sure that the network security key has not been modified. WPA also authenticates users to help ensure that only authorized people can access the network.
There are two types of WPA authentication: WPA and WPA2. WPA is designed to work with all wireless network adapters, but it might not work with older routers or access points. WPA2 is more secure than WPA, but it will not work with some older network adapters. WPA is designed to be used with an 802.1X authentication server, which distributes different keys to each user. This is referred to as WPA-Enterprise or WPA2-Enterprise. It can also be used in a pre-shared key (PSK) mode, where every user is given the same passphrase. This is referred to as WPA-Personal or WPA2-Personal.

Wired Equivalent Privacy (WEP)

WEP is an older network security method that is still available to support older devices, but it is no longer recommended. When you enable WEP, you set up a network security key. This key encrypts the information that one computer sends to another computer across your network. However, WEP security is relatively easy to crack.
Warning

Warning

We don't recommend using WEP. WPA or WPA2 are more secure. If you try WPA or WPA2 and they don't work, we recommend that you upgrade your network adapter to one that works with WPA or WPA2.

802.1X authentication

802.1X authentication can help enhance security for 802.11 wireless networks and wired Ethernet networks. 802.1X uses an authentication server to validate users and provide network access. On wireless networks, 802.1X can work with Wired Equivalent Privacy (WEP) or Wi‑Fi Protected Access (WPA) keys. This type of authentication is typically used when connecting to a workplace network.

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Basics of Connecting and Setting Up a Wireless Home Network

Sharan R >> , , , ,
Having Internet access at home is convenient, but wouldn't it feel good to relax on the couch while you check your bank account balance or shop online? At the same time, your daughter could research that book report on her computer while using the same wireless network connection that you're using. When you set up a wireless home network, it's all possible—and it's a lot easier than you might think.

What is a wireless home network?

A home network is simply two or more computers in your home that are connected to each other and can share files, printers, and your Internet connection. In a wireless network, the computers are connected by radio signals instead of wires or cables, which is perfect for mobile PCs: notebooks, Tablet PCs, and ultra-mobile PCs.
Illustration of a wireless home network
A wireless home network
The good news is that having a computer network in your home is no longer as expensive or as hard to set up as it once was. In just an afternoon, you can make viewing your bank account or researching that book report from anywhere in the house a comfortable and convenient reality.

The right equipment

Before you can set up your wireless home network, you need the following things:
  • Broadband connection and modem
  • Wireless network adapters and a wireless router

Broadband connection and modem

A broadband connection is a high-speed Internet connection, in contrast to a dial-up connection, which is slower and is not powerful enough for a wireless home network. There are different types of broadband connections. DSL and cable are two of the most common ones. You can get a broadband connection by contacting an Internet service provider (ISP) that offers broadband service. ISPs often provide the broadband modem as well, and may even install it for you.
After you have a broadband connection and modem, you can get the rest of the hardware that you need for your wireless home network.

Wireless network adapters and a wireless router

A network adapter is a hardware device that connects your computer to a network. Most mobile PCs—and many desktop computers—come with a wireless network adapter already installed. You can check each of your computers yourself to see whether they have wireless network adapters. Here's how to determine whether a computer has a wireless network adapter:
  1. Click the Start button Picture of the Start button, click Control Panel, click System and Maintenance, and then click System.
  2. In the left pane, click Device Manager.
  3. Next to Network adapters, click the plus sign (+).
  4. Look for a network adapter that includes "wireless" in the name.
If one or more of your computers needs a wireless network adapter, you can purchase it from a store that sells computer accessories, and then install it yourself.
If you do need to buy wireless network adapters, it's a good idea to get the same brand as the wireless router that you buy. Hardware from the same manufacturer often works better together than hardware from different manufacturers. For more information, see Wireless networking: frequently asked questions in Windows Help and How-to.

Where to put your wireless router

Follow these tips for placing your wireless router in an area that will give you the strongest signal strength and best connection.
  • Position your wireless router in a central location. Avoid placing your router next to an outside wall of your home. Most router antennas are omni-directional. This means that the signal radiates from the antenna in all directions equally. Place the router as close to the center of your home as you can to increase the strength of your wireless signal throughout your home.
  • Move the wireless router off of the floor and away from walls and metal objects, such as metal file cabinets. Putting your router on the floor, or next to walls or metal objects, can diminish the signal strength, because the router's signal is broadcast in the shape of a sphere. The fewer physical obstructions between your computer and the router's signal, the more likely that you'll be using the router's full signal strength. This means a stronger Internet connection from greater distances in your home. For more information, see 10 tips for improving your wireless network.
  • Reduce wireless interference. Your cordless phone or other wireless electronics are sending signals, too. If they're close together, they may interfere with each other. You can help prevent interference by changing the location of your cordless phone base station, changing the frequency channel on your wireless router, or avoiding wireless electronics that use the 2.4-gigahertz (GHz) frequency. If you have trouble reducing the amount of wireless interference, look for cordless phones and other wireless electronics that use the 5.8-GHz or 900-megahertz frequencies.
  • Upgrade 802.11b devices to 802.11g. The 802.11g standard is the high-bandwidth successor to 802.11b, and it's nearly five times faster. This increased speed is noticeable if you're sending information from one computer to another on your home network—for example, sending pictures from your mobile PC to your desktop computer—however, it's not as evident when you're simply accessing the Internet. If you're adding a computer to an existing network, you may want to upgrade the other components to 802.11g at the same time.
After you purchase all of the pieces, you have your broadband connection, and you know where you're going to place your wireless router, you're ready to put together your wireless home network. Follow the instructions that came with your router and network adapters, and then activate your router—set the user name, password, and IP address—according to the instructions from your ISP.

Help protect your network

After you set up your home wireless network—but before you connect to the Internet—it's time to help protect it with a few security measures: a network security key, wireless router security, and firewalls.

Network security key

Just as file cabinets have keys and safes have combinations, wireless networks have a network security key, a password that can help protect wireless networks from unauthorized access. Because wireless networks can be seen by outsiders who can pick up the signal, you need to protect your personal information and files.
To establish a network security key, simply run the Set up a wireless router or access point wizard, which makes your network private by issuing a network security key. The wizard also helps you configure a wireless router or access point, set up file and printer sharing, and connect other computers and devices to your network. Here's how to run the Set up a wireless router or access point wizard:
  1. Click the Start button Picture of the Start button, click Control Panel, click Network and Internet, and then click Network and Sharing Center.
  2. In the left pane, click Set up a connection or network.
  3. In the Choose a connection dialog box, click Set up a wireless router or access point, and then click Next.

Wireless router security

There are two additional methods of securing your wireless network: Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access (WPA).
WEP is a basic security measure that comes standard with most routers. It helps to protect your wireless network from unauthorized access by requiring users to enter a network security key before connecting to the network.
WPA is a more robust security measure than WEP because, rather than simply requiring a network security key to access the network, it provides user authentication so that hackers are less likely to gain access to your network. However, WPA doesn't come standard on some routers. For more information about WPA, see your router manufacturer's website.
For more information, see Making your network more secure in Windows Help and How-to.

Firewalls

A firewall is hardware or software that can help protect your computer from hackers or malicious software, which is software designed to deliberately harm your computer (for example, viruses, worms, and Trojan horses). Running a firewall on each computer on your home network can help control the spread of malicious software on your network, as well as help to protect your computers when you're accessing the Internet on public networks, such as your local Internet café. For more information, see Firewall: frequently asked questions in Windows Help and How-to.
Illustration of how a firewall can help protect a computer
A firewall can help protect a computer
For additional protection, some new routers come with a built-in Stateful Packet Inspection (SPI) firewall, which analyzes and filters out malicious data before it can access your network. For more information, see your router manufacturer's website.

Relax, that's all there is to do

Setting up a home network is not difficult, but sometimes the occasional hiccup occurs. If you need help, check the instructions that came with your hardware or search Windows Help and How-to for more information. Set aside enough time so that you don't feel rushed. In just a little while, you and your family will be sharing your Internet connection—and you'll be doing your online shopping from the comfort of your couch or the convenience of your dining room table or patio.
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CCNA INTRO: Introduction to Cisco Networking Technologies Study Guide: Exam 640-821

Sharan R >> , , ,
CCNA INTRO: Introduction to Cisco Networking Technologies Study Guide: Exam 640-821
Publisher: Sybex | ISBN: 0470068507 | edition 2006 | PDF | 509 pages | 15,5 mb

From bestselling author Todd Lammle comes the most up-to-date book on CCNA exam 640-821, the first exam in Cisco's popular two-exam Cisco Certified Network Associate (CCNA) certification track. Understand networking for the small or home office market, prepare for the exam, and acquire the skills you need with this comprehensive guide.
Inside you'll find:
Complete coverage of all exam objectives in a systematic approach, so you can be confident you're getting the instruction you need Practical hands-on exercises to reinforce critical skills
Real-world scenarios that show you life beyond the classroom and put what you've learned in the context of actual job roles Challenging review questions in each chapter to prepare you for exam day Exam Essentials, a key feature at the end of each chapter that identifies critical areas you must become proficient in before taking exam 640-821 A handy tear card that maps every official exam objective to the corresponding chapter in the book, so you can track your exam prep objective by objective Look inside for complete coverage of all exam objectives.
Download:
Depositfiles
Or
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IPv6 - Definition

Sharan R >> , , ,
IPv6 is the next generation protocol for Internet networking. IPv6 expands on the current Internet Protocol standard known as IPv4. Compared to IPv4, IPv6 offers better addressing, security and other features to support large worldwide networks.

In IPv6, IP addresses change from the current 32-bit standard and dotted decimal notation to a new 128-bit address system. IPv6 addresses remain backward compatible with IPv4 addresses. For example, the IPv4 address "192.168.100.32" may appear in IPv6 notation as "0000:0000:0000:0000:0000:0000:C0A8:6420" or "::C0A8:6420".

The most obvious benefit of IPv6 is the exponentially greater number of IP addresses it can support compared to IPv4. Many countries outside the U.S. suffer from a shortage of IP addresses today. Because IPv6 and IPv4 protocols coexist, those locales with an address shortage can easily deploy new IPv6 networks that work with the rest of the Internet. Experts believe it will take many more years before all networks fully change over to IPv6.

Other benefits of IPv6 are less obvious but equally important. The internals of the IPv6 protocol have been designed with scalability and extensibility in mind. This will allow many different kinds of devices besides PCs, like cell phones and home appliances, to more easily join the Internet in future.
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IP address - Definition

Sharan R >> , , ,
An IP address is a logical address for a network adapter. The IP address uniquely identifies computers on a TCP/IP network.

An IP address can be private - for use on a local area network (LAN) - or public - for use on the Internet or other wide area network (WAN). IP addresses can be determined statically (assigned to a computer by a system administrator) or dynamically (assigned by another device on the network on demand).

Two IP addressing standards are in use today. The IPv4 standard is most familar to people and supported everywhere on the Internet, but the newer IPv6 standard is planned to replace it and starting to be deployed.

IPv4 addresses consist of four bytes (32 bits). Each byte of an IP address is known as an octet. Octets can take any value between 0 and 255. Various conventions exist for the numbering and use of IP addresses.

Common IP (IPv4) Addresses -
  • 10.0.0.1
  • 127.0.0.1
  • 192.168.0.1
  • 192.168.1.1
  • 192.168.2.1
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FTP - Definition

Sharan R >> , , ,
FTP allows you to transfer files between two computers on the Internet. FTP is a simple network protocol based on Internet Protocol and also a term used when referring to the process of copying files when using FTP technology.

To transfer files with FTP, you use a program often called the "client." The FTP client program initiates a connection to a remote computer running FTP "server" software. After the connection is established, the client can choose to send and/or receive copies of files, singly or in groups.

To connect to an FTP server, a client requires a username and password as set by the administrator of the server. Many public FTP archives follow a special convention for that accepts a username of "anonymous."

Simple FTP clients are included with most network operating systems, but most of these clients (such as FTP.EXE on Windows) support a relatively unfriendly command-line interface. Many alternative freeware / shareware third-party FTP clients have been developed that support graphic user interfaces (GUIs) and additional convenience features. In any FTP interface, clients identify the FTP server either by its IP address (such as 192.168.0.1) or by its host name.

FTP supports two modes of data transfer: plain text (ASCII), and binary. You set the mode in the FTP client. A common error when using FTP is attempting to transfer a binary file (such as a program or music file) while in text mode, causing the transfered file to be unusable.
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Free FTP Server Softwares

Sharan R >> , ,
An FTP server is a required software application on networks that wish to support file sharing using the File Transfer Protocol. This page lists the best FTP servers available for the Windows operating system. Evaluation versions of each of these FTP server software products can be downloaded from the vendors' sites.

1. WS_FTP Server

WS_FTP Server is the choice for high-end needs. Though it costs more than competitors' FTP servers, it is extremely robust and full-featured. WS_FTP Server supports 128-bit SSL encryption, nice installation wizards and a full administrative GUI. It also features a built-in log analyzer. WS_FTP Server is designed to run on true Windows servers; it runs on Windows NT, Windows 2000, and Windows XP.

2. War FTP Daemon

War FTP daemon is free FTP software that is also Open Source in current development. It runs on most popular versions of Windows and is designed for a range of needs from basic to advanced. War FTP has been developed over many years and has proven itself as a stable and mature freeware Windows FTP server.
Vendor's Site

3. zFTPServer Suite

Now at version 3.0, zFTPServer Suite is still a free Windows FTP server and has gained a loyal following. It features multi-lingual user interfaces, flexible access control for both accounts and IP addresses, and passive as well as active mode connections. zFTPServer supports all popular Windows operating systems (except Vista) and is designed for ease of use by beginning- and intermediate level users. Some third-party extensions to zFTPServer for advanced, enterprise-level functionality are available at additional cost.

4. FileZilla Server

Another free Windows FTP server download, FileZilla Server is an especially active Open Source community project with both binary and full source code downloads available. FileZilla Server tracks the user ids of all connected sessions and each file transfered.
Vendor's Site

5. Serv-U FTP Server

Serv-U strikes a good balance between cost, features, and stability. Serv-U is one of the most mature Windows FTP servers. Over time, it's user interface has been revamped, SSL support added, and overall robustness improved. Serv-U runs on all popular versions of Windows including Windows 95 and Windows 98 as well as Windows NT and the newer Windows platforms. It is priced affordably.
Vendor's Site

6. Xlight FTP Server

The Xlight personal edition FTP server is free for use by individuals, while standard and professional editions are also available. For businesses, Xlight features Active Directory and LDAP integration support, 128-bit SSL, virtual server support, and a remote administration GUI. It also supports IPv6 networks.
Vendor's Site

7. Golden FTP Server

This FTP server is designed for simplicity and those unfamiliar with FTP or managing servers. The free version supports multiple languages but does not support user accounts, advanced statistics and some other options available in a paid upgrade version.
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Server - Definition

Sharan R >>
A network server is a computer designed to process requests and deliver data to other (client) computers over a local network or the Internet.
Network servers typically are configured with additional processing, memory and storage capacity to handle the load of servicing clients. Common types of network servers include:
  • Web servers
  • Proxy servers
  • FTP servers
  • Online game servers
Numerous systems use this client / server networking model including Web sites and email services. An alternative model, peer-to-peer networking enables all computers to act as either a server or client as needed.
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