How to Find the Subnet Mask

The network is divided into several subnetworks for faster data transmission and easier management. Routers do this by assigning subnet masks, a series of numbers that represent where to look in an IP address so that subnets can be identified. ^{[1] X Research Source} In most cases, finding the subnet mask on a computer is quite simple. However, on other devices it can be more complicated. If another device asks for a subnet mask, you can use the same parameters as on the computer.

Table of Contents

On Windows

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Open Command Prompt. Press the Windows key and R at the same time to open the Command Prompt window.

If the Command Prompt doesn’t open, click the Start button or the Windows icon in the lower-left corner of the screen. Then, type “command prompt” in the search bar and double-click the icon that appears. You may also need to click the Search button first to access the search bar.
If there are no icons at the bottom left of the touch screen, move your mouse pointer to the bottom right and swipe up or swipe from the right.

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Enter the command ipconfig. Type the exact ipconfig /all command including a space in the middle, then press ↵ Enter . Windows ipconfig is a program that tracks all networks and this command will open a list containing all network information.

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Find the subnet mask. This option is in the “Ethernet adapter Local Area Connection” section. Look for the line that begins with “Subnet Mask” and look closely to determine the subnet mask. ^{[2] X Research Source} Most subnet masks are numbers that start with 255, such as 255.255.255.0.

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Or you can look in the Control Panel. Here’s another way to find this information:

Go to Contrp Panel → Network & Internet → Network and Sharing Center.
On most new Windows operating systems, click “Change adapter settings” on the left. For Windows Vista, click “Manage Network Connections”. ^{[3] X Research Sources}
Right click on “Local Area Connection” and select “Status”. Then you click “Details” on the window that opens and find the parameter subnet mask ^{[4] X Research Source}

On Mac

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Click the “System Preferences” icon in the Dock. If the Dock does not have this icon, click the Apple icon in the upper left of the screen and select “System Preferences”.

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Click the “Network” icon. On most versions of Mac OS X, the gray globe icon is usually located in the “System Preferences” window. If you can’t find it, type Network in the search bar at the top right of the System Preferences window.

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Select Internet connection from the list on the left. Click on the network name that shows the green dot and “Connected” status below.

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Click “Advanced” if you use WiFi. This option is in the lower right of the window. With most connection types, you will see the Subnet Mask parameter displayed on the right side of the screen.

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Select the TCP/IP tab in the “Advanced” window. TCP/IP on Mac specifies the network access protocol.

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Find the subnet mask. The subnet mask will be labeled “Subnet Mask” and begin with the number 255.

If the only numbers you see are in the bottom half of the screen, under the “Configure IPv6” heading, you’re connecting to an unused IPv6 local area network. subnet mask. If you want to go online, you need to select “Using DHCP” from the “Configure IPv4” menu and then click Renew DHCP Lease .

On Linux

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Open command line. If you don’t know how to open the command line, you need to check out the instructions specific to the Linux release on your machine. You should also familiarize yourself with the command line environment before proceeding.

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Enter the ifconfig command. On the command line, type ifconfig and then press ↵ Enter . ^{[5] X Research Sources}

If nothing happens other than saying that you must be an administrator, follow this guide to get root access.

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Find the subnet mask. This information will be labeled “Mask” or “Subnet Mask” and begin with the number 255.

Set up a TV or other device

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Use the same parameters as on the computer. When setting up a smart TV or other device, you may need to enter a subnet mask. This parameter is specified for the local area network. If you want optimal results, follow the instructions above to find the subnet mask on your computer. This parameter can also be applied to other devices in the network.

If the device still won’t connect, open the information on your computer to both consult and change the device’s settings.
If you can’t find the subnet mask on your computer, you can try entering the number 255.255.255.0. This is the subnet mask common to most home networks.

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Change IP address. If the device still can’t come online, you need to check the IP address. This information is also on the subnet mask settings window. You can use any number of methods to find the subnet mask and compare it with the IP address on the computer. Then, copy the entire IP address of the computer except the last number or group of numbers after the last dot and replace it with a larger number (but less than 254). You should replace it with a larger number at least 10, as closer numbers may already be used by other additional devices in the network.

For example, if the computer’s IP address is 192.168.1.3, you can set the device IP address to 192.168.1.100.
If you can’t find your computer’s IP address, you can check the label on your router or search for a keyword that includes the router brand associated with “IP address” or “IP address” on the network. Then change the last digit group of the address and use it for the new device.
If you still can’t find the information, you can try the numbers 192.168.1.100, 192.168.0.100, 192.168.10.100 or 192.168.2.100.

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Gateway Gateway Setup. This Gateway value needs to be set up similar to that on the computer, this is also the IP address of the router. This value is almost the same as the device’s IP address, except for the last group of numbers (replaced with 1).

For example, if some device in the network has an IP address of 192.168.1.3, you can set the value 192.168.1.1 for the Gateway port.
On any browser, enter http:// with the Gateway value. The router’s information page will open if the Gateway port is correct.

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Set up DNS. You can reuse your computer’s DNS settings or the Gateway value. Besides, you can also search for “public DNS” or “public DNS” online to see more options.

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Contact the manufacturer. If the device still cannot connect after setup, you need to contact the manufacturer’s technical support.

Advice

If the subnet mask shows all zeros (for example, 0.0.0.0), you’re probably offline.
The subnet mask will be displayed on the active adapter. For example, if you are using a Wi-Fi card, the subnet mask will appear below the wireless network card. If your computer has multiple adapters such as a Wi-Fi card and a network card, you may need to scroll up or down to find the field.
IPv6 networks do not use subnet masks. The subnet IP is always built into the IP address. ^{[6] X Research Source} The fourth group of characters separated by a semicolon (or the 49th–64th binary value) is the parameter representing the subnet.

Warning

When changing the subnet mask, the Internet connection may be lost.

Steps