Secure Your Wifi: Pt 4 Reduce the Size of the Default Subnet

If you’re like most people, you may not give much thought to your home Wi-Fi settings beyond connecting your devices. But did you know that making a few simple adjustments to your network can improve security? One of these steps is to reduce the size of your network’s “subnet.”  This is going to be one of the more complex configurations to implement in this series, as subnetting is usually a hard concept for many to grasp.  While it is a hard concept, we have created a tool that will help you find the correct settings that work for your setup.

In technical terms, a subnet is a smaller network within your main network, allowing you to limit the number of devices that can connect to your Wi-Fi. Most home networks come with a default IP address range like “192.168.0.1” to “192.168.0.255,” which is standard across many routers. Unfortunately, this range is well-known, making it easier for unauthorized users to target your network. By reducing the size of your subnet, you can limit the number of available IP addresses and create fewer points of access, making it harder for unwanted devices to connect.

What is a Subnet and an IP Address Range?

• IP Address Range: Every device connected to your Wi-Fi needs an IP address, which is like a unique identifier for that device on your network. Most routers automatically assign these IP addresses from a set range, usually starting at “192.168.0.1.” The default IP range in home routers typically spans from “192.168.0.1” to “192.168.0.255,” allowing up to 254 devices to connect.

• Subnet: Think of a subnet as a way to divide your network into smaller sections. This division allows you to manage how many devices can connect by limiting the number of IP addresses available in the network. A smaller subnet reduces the number of devices that can be on the network, which helps block unauthorized users.  This is done by using what is called a "subnet mask", "255.255.255.0", or a "CIDR" (Classless Inter-Domain Routing) "\24".  In networking 255.255.255.0 and \24 are the same and allow 254 hosts to join to the network.

• IP Address + Subnet Mask/CIDR:  The combination of the IP address and the subnet mask, or CIDR, determine the size of the network, and how many IP addresses can be assined from the wireless router.

By reducing the size of your subnet, you control how many devices can connect, adding an extra layer of security to your network. But before you get started, it’s helpful to know how many devices you regularly connect to your Wi-Fi so you can set the subnet to fit your needs.

How to Reduce the Size of Your Subnet

Here’s a step-by-step guide to shrinking your subnet size:

1. Log Into Your Router’s Settings: Most routers can be accessed by typing an IP address (usually something like “192.168.0.1” or “192.168.1.1”) into your web browser. You’ll be prompted to enter your login details, typically provided in the router’s manual or on a sticker on the device.

2. Navigate to LAN or DHCP Settings: Once you’re in, look for settings labeled “LAN” (Local Area Network) or “DHCP” (Dynamic Host Configuration Protocol). This is where you can adjust your IP address range and subnet settings.

3. Reduce the IP Address Range: In the DHCP settings, you’ll likely see a field for setting the range of IP addresses your router assigns to devices. This range might be from “192.168.0.1” to “192.168.0.255” by default, which allows up to 254 devices. To reduce the range, change it to something like “192.168.0.100” to “192.168.0.150.” This smaller range allows only 50 devices to connect.

4. Adjust the Subnet Mask: A subnet mask further limits the number of devices that can connect. The default subnet mask in most home networks is 255.255.255.0, which allows for a full range of IP addresses. You can reduce this based on the number of devices you want to support. For example, a subnet mask of 255.255.255.192 allows up to 64 devices, while 255.255.255.224 allows up to 32. To calculate the right subnet for your network, you can use our Subnet Calculator to ensure you’re meeting your needs without leaving too many IPs open.

Why Reducing Your Subnet Size Matters

Limiting your network’s subnet size is an easy but effective security measure. Here’s how it helps:

• Fewer Points of Access: By reducing the IP address range, you limit the number of devices that can connect, decreasing the number of entry points for unauthorized users.

• Reduced Risk of Unauthorized Connections: With fewer available IP addresses, it becomes harder for unauthorized devices to slip into your network. This can be particularly useful for people living in apartment buildings or areas with high Wi-Fi density.

• Better Control Over Your Network: By understanding and managing your subnet, you gain more control over what devices can connect to your network. This is especially helpful as the number of smart home devices continues to grow.

Reducing your subnet size is an easy way to boost security and protect your personal devices. With just a few tweaks, you can gain peace of mind and enjoy a safer, more secure Wi-Fi network.