Forming a small network at home (PART I)

Covering the basics
Before I had built my first network I used to think it would be an overwhelming task to build a network from scratch. In time I have come to know better. I was planning on getting DSL at home and I had more than one computer and I wanted to share the Internet on all of them.

There are several ways you may form a network. A simple and effective network topology for your home would be a star network. In this type of network there is a central switch/hub which links the computers together. You will also need to decide how your network parameters are propagated to all the computers in your network. I will describe three ways in my articles:

• PART I - Covering the basics
• PART II - Setting parameters manually on all computers
• PART III - Your DSL router acting as a DHCP server
• PART IV - Setting up your own DHCP server

Here, it is important to know what DHCP is. DHCP stands for "Dynamic Host Configuration Protocol" and is used by networked devices to obtain parameters necessary to operate properly in a particular network. These parameters include the gateway, DNS, IP address, subnet mask, etc. A DHCP server is a computer on your network which is delegated to assign IP parameters to computers joining your network.

The ingredients required to form a simple network are: two or more computers each with LAN cards installed, a network switch/hub, and patch cords equal to the number of computers in your network. Patch cords used here are straight network cables (which provide parallel connections at both ends).

The basic stuff you need to know here is what an IP address is and the use of the ping command. An IP address is like your home address and it identifies your computer uniquely over a network. The ping command uses the IP address to verify whether a network interface of a computer is accessible or not. I will elaborate on the use of the ping command as we go along.

I think we have covered enough basics to start forming the network now. We will start with setting a network with two computers and a network switch in PART II of this article.

Changing Network Authentication Mode

When I had completed installing the network at home, I tried to access the hidden folders on my bro's computer. I was presented with a prompt asking me to authenticate as a guest. The user name field was hard coded with "Guest" and was unchangable.

(For the context of this article I will refer to the machine sharing the folders as "remote computer". Also, this article has been written for Windows XP.)

Such a user prompt essentially stops you from accessing the hidden shared folders on the remote computer even if you know the login information. This is due to the reason that most computers do not have the guest account enabled, and the prompt forces you to authenticate as a guest. Of course all authentication attempts will fail if the guest account is disabled on the remote computer.

To change this authentication mode just follow these steps (on the remote computer).

1. Go to Start Menu > Settings > Control Panel > Administrative Tools > Local Security Policy.
   
2. A new window for Local Security Policy will open. There on the left pane, expand "Local Policies".
   
3. Inside Local Policies (still on the left pane), click on "Security Options".
   
4. On the right pane, find an entry named "Network Access: Sharing and security model for local accounts" and double click it.
   
5. In the dialog window that opens, select "Classic - local users authenticate as themselves" from the combo box.
   
6. Click on OK.

There you go. Now when you try to access the remote computer, you are presented with a prompt where you can enter both user name and password. Once you provide the correct login information, you will be able to access the hidden shared folders on the remote computer.

Hidden shared folders in Windows

Desktop Windows Operating Systems such as Windows XP, Windows 2000, etc. share the root of your hard disk drives by default. For example, if you have three partitions on your hard drive then your "C:\", "D:\" and "E:\" drives are shared by default. These shares are hidden, and they are not shown when you access a network computer by entering "\\computerName" in your "Run" dialog box. The reason for keeping them hidden is because these shares are meant for administrative purposes only. But there is a way to access these shares.

Before we start accessing these shares, let us first verify whether the roots of the partitions are shared. In your Windows Explorer, simply right click your drive name and select "Sharing and Security...". Here you will see that the share name is "C$". The magical character here is the "$". In fact, if you use this character while sharing other folders, those shares will be hidden as well. The catch is to use this character at the end of the share name, otherwise the share is not hidden.

Now let us proceed to accessing these hidden shares. The task is very simple. Just enter "\\computerName\C$" in your "Run" dialog box and the contents of the remote computer's "C:\" drive will be displayed. Same procedure goes for other shares that you have decided to keep hidden; instead of "C$", provide the share name for the particular shared folder (including the character $).

We have left out one intermediate step though. When you type in "\\computerName\C$", Windows will prompt for authentication. Here you must enter the Windows login information (username and password) of the remote machine. Remember what we discussed a few moments ago? These shares are meant for administrative purposes only. Therefore, only the credentials having administrative privileges on the remote computer will be able to access these hidden shares.

Now you know how to access hidden shared folders on a machine and how to keep your shares hidden. But, even if you know the username and password for an administrative account of the remote computer, there is still a quirk in default configuration of Windows that will hinder with your goal. But that is a topic for our next discussion.

Hello Folks

Hi everyone,

Welcome to my Blog. I will be posting solutions to problems that I face with my Operating System or applications. Hope they will be helpful to you guys as well.