Advice 1: How to determine the subnet mask

What mask of a subnet? If you try to explain graphically, we can represent the network ID in the form of the street name and the computer ID as the house number on the street. Take, for example, the address Troitskaya, 15, where "15" is the ID of the computer, and "Trinity" — the network ID. The subnet mask indicates what part of the IP address is the network ID and which is host ID. How to determine the mask of the subnet? There are several ways.
How to determine the subnet mask
The first method is that the subnet mask specified in the network connection properties. In order to see it, you must go to the following address:For Windows XP. "Start" -> "settings" -> "control Panel" -> "Network connections". On the active connection, click the right mouse button. In the opened window, in the Protocol list, find "Internet Protocol (TCP/IP)" and click "Properties". In the opened settings window, in the corresponding row you will see the subnet mask.For Windows 7. "Start" -> "control Panel" -> "Network and Internet" -> "View network status and tasks". In the list of active networks click on active connection. In the window that opens, click "Details". In the resulting list, the appropriate line will indicate the subnet mask.
Most often it so happens that all the connection settings, the computer gets automatically, and they are not specified in the connection properties. In this case, come to the aid of method number two. You must first open a Windows command prompt. This can be done via: start - > All programs - > Accessories - > Command prompt. Or: start - > Run cmd.exe". After that you will open a command prompt window. It is necessary to write the command ipconfig. Enter the command, hit Enter and the command prompt window displays a list of network settings. It only remains among them to find the subnet mask.

Advice 2 : How to find subnet mask

To determine the address length of the subnet, you need to use a specialized name - mask. Using this number, you can determine which part of the specified IP-address to specify the network. Therefore, the ability to find it is one of the most important.
How to find subnet mask
The allocation of addresses to organizations was difficult. Introduction categories of networks greatly facilitated this task. But it became impractical when using multiple computers in the node. For rational use of organized subnet, which consists of the class A, B or C and contains a field called (subnet field). For this value requires more bits, which, in turn, belong to the host part. Thus, one network can be divided into two subnets (at least). To determine the address in this case becomes very difficult. Programming began to use a new term - the mask of the subnet. It implies the length of the addresses of each subnet. To determine the mask, you need to do the following: to begin to record the IP address in binary form. To make this procedure requires the discharges that belong to the network and subnet parts, to replace the units, all values that belong to the host portion, on the zeros. In the end, you will receive the mask of the subnet.
If you do not know your IP address, you can use the second method. In the network connections properties most often indicated mask subnet. To view it, follow these steps: open the start menu; then go to the "control Panel". In the opened window you will see a list of CPU tasks. Go to "Network connections". Visiteuses in the list find "Internet Protocol (TCP/IP)". Open the menu "Properties". In the settings select "Mask subnet".
Sometimes it happens that you configure all subnets computer automatically gets the properties of "Internet Protocol (TCP/IP)" does not display them. In this case, you can do so: open a Windows command prompt. To do this go to "start" then "All programs", Accessories, "Command prompt". Dialog box opens. Type the command ipconfig, then you will see a list of all addresses of networks and subnets available. Find the desired mask.
Useful advice
If you open "Network connections" in "Internet Protocol (TCP/IP)" you can read your IP address. Not to take further action in step 2, you can write the address in binary form, as stated in step 1. This will help you reduce time costs.
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