IP addresses form the backbone of every network, including the internet. However, with so many randomly generated IP addresses floating around, frequently accessed devices on a network like a router require a constant, easy-to-remember address.

Additionally, since we only have a limited number of IPv4 addresses on the internet, assigning every device that connects to the internet a unique IP address is challenging. This is where reserved IP addresses come into the picture. They're an important part of every network, making administrative tasks far less of a guessing game.

What Is a Reserved IP Address?

Every website you access on the internet is actually a server's IP address masked behind an easy-to-remember phrase called the URL (Uniform Resource Locator). However, not all IP addresses are the same. Generally speaking, IP addresses are divided into five classes, from Class A to Class E.

Some IP addresses from classes A, B, and C are reserved as private IP addresses. They're only accessible on local networks like the one found on your university or office network.

Their only purpose is to create a separate range of private IP addresses to properly distribute devices in the already-limited IPv4 range. By creating private IP addresses for each network, global demand for unique IP addresses can be massively reduced.

A great example of this is to check your local IP address. On your home Wi-Fi network (or just about any network), if you were to check your computer's IP address, you'll see a number like 192.168.xx.xx. This will differ from your global IP address, which is assigned to the router instead of individual devices. We've also covered how to find all IP addresses on your network should the moment arise.

What IP Addresses Are Commonly Reserved?

In the IPv4 addressing scheme, the following addresses are generally reserved.

• 10.0.0.0-10.255.255.255
• 172.16.0.0-172.31.255.255
• 192.168.0.0-192.168.255.255

The first set contains over 16 million addresses, the second around one million, and the third about 65,000 addresses. IP addresses ranging from 0.0.0.0 to 0.255.255.255 are also reserved, but they don't do anything.

The most common reserved IP address you'll come across is 127.0.0.1. This is called a loopback address and is used to test the network adaptor inside a device. Any traffic going to 127.0.0.1 is sent over a local network or the internet.

IPv6 functions slightly differently. While IPv4 has many small reserved blocks in different locations of its address space, reserved IP addresses in the IPv6 range start from the very top, "0000 0000" or 00 for the first hexadecimal octet. This represents 1/256th of the total IPv6 address space. IPv6 is yet to take over IPv4 (though it is in use), so it'll be a while before you see reserved IPv6 addresses come into play.

How Do You Reserve an IP Address?

Generally speaking, you wouldn't need to reserve IP addresses on a network as most devices come pre-configured with an IP address that you can use to access them on a network quickly.

However, you can play around with the particular reserved IP address subset that the network you're working with uses to manually assign "static" IP addresses to a particular device on a local network. This is done using your router's DHCP settings.

The exact process will vary based on your router's make, model, and network requirements. That said, you'll likely find these settings hidden under IP assignment or DHCP server settings in your router. Our guide on setting up a static IP address on a Windows PC should give you everything you need.

IP Addresses Are Important

IP addresses are an important part of the internet and even more so on our local networks. Having a dedicated set of IP addresses reserved for internal networks helps cut down on the overall number of IP addresses required to identify each device on the internet and quickly distinguish between devices on a local network.

You can take this even further by reserving internal IP addresses for specific devices on your local network. This can help you quickly identify and connect to devices you might want to access over your network.