What are internal IP address ranges?

Internal IP addresses designate which device in a local network is your computer, compared to other devices which might be using the intranet connection. An internal IP address is also called a local IP address. Usually, this IP address begins with 192.168. Then, after the 8, there will be a period and a final series of three unique numbers. This IP address can be seen by other devices connected to your intranet, but it cannot be seen by external devices through the internet. Your IP address is used to uniquely identify your device or network. There are specific encoding standards set by the Internet Assigned Numbers Authority (IANA) so that no two IP addresses are exactly the same, although they have similar formatting. Your private or internal IP address is assigned to you by a Network Address Translation (NAT) device. Using private IP addresses reserves public or external IP addresses for, essentially, public network use. Many people currently have several devices in their homes connected to the internet, such as laptops, smart TVs, mobile phones, tablets, gaming consoles, and many others. Rather than giving each of these devices a unique external IP address to access the internet, your ISP provides one external IP address to your router, which then uses internal IP addresses to connect to each of your devices.

Differences between internal & external IP addresses

Generally, your internal IP address is your device’s designation for your internal network, whether this is an ethernet connection or the connection between your device and your router. Your external IP address is assigned to your router by your internet service provider (ISP). When thinking about IP addresses, most people are concerned with their external IP address, but your internal IP address is also important. In contrast to your internal IP address, an external IP address is designated to your device by your ISP. This external IP address allows devices across the internet to find your device in order to share information, like social media updates. Your ISP assigns different IP addresses to the devices that log into your particular WiFi network, so they can track your internet use, including your search history and login information, and store it on their own servers. While the worst thing most ISPs do with this data is sell it to advertising companies, who use it for targeted advertising on websites and social media, this storage also makes you susceptible to data breaches if a hacker breaks into the ISP’s server.< However, the router you use to connect to the internet is considered part of your internal network. This router also assigns internal IP addresses to your devices when they access the router. Typically, this is the same IP address for each device rather than a unique IP address. Anyone can see your external IP address when you access the internet, but information you receive from the internet is sent through the router to your device based on your assigned internal IP address, which no one can access without breaking into your internal network. The IANA has defined these IP addresses as private or local:

• 10.0.0.0 to 10.255.255.255, a range that provides up to 16 million unique IP addresses
• 172.16.0.0 to 172.31.255.255, providing about 1 million unique IP addresses 
• 192.168.0.0 to 192.168.255.255, which offers about 65,000 unique IP addresses 

These are all part of IPv4, which are the most widely used IP addresses in the world. There are also some IP addresses assigned to IPv6, which you may find when you look on your computer for your IP address. However, these were issues out of concern that the world would quickly run out of unique IPv4 addresses, which has not occurred yet.

How to find your external IP address

One of the easiest ways to find your external IP address is, ironically, to ask the internet. Websites like WhatIsMyIP.com will ping your computer and show you both your IPv6 and IPv4 addresses. As of 2021, only the IPv4 address is relevant for most people, but IPv6 is becoming increasingly relevant. While there are many internal system differences between Windows and Apple computers, and differences between computer and mobile phone operating systems, these do not impact how you find your external IP address. You can use a search engine to find a site that will tell you your IP address, in IPv4, IPv6, or both.

How to find your internal IP address

Although there are simple ways to find your external IP address, different devices and operating systems have different ways for you to access your internal IP address. Here are some of the more common methods:

• Windows: To find your internal Windows IP address, open your command prompt through the Start menu. Type in “ipconfig,” then hit enter. Find the line with “IPv4,” which will have a number often starting with 10. If you want to always know your internal IP address, you can download an app like Rainmeter, which will display your IP address on your desktop at all times. &
• Mac: On Apple computers, you can get your internal IP address by clicking the Apple icon in the top left and opening System Preferences. Next, click Network, and then, find your connection type — either WiFi or Ethernet — and click that. Usually, there will be a green dot to let you know whether this connection is active or not. Under the “Status: Connected,” you should have information on your IP address, which will often start with 10. Like Windows computers, some app companies have designed programs like IP in Menubar, which you can run all the time to constantly know your internal IP address.
• Android: While there are a wide range of Android phones, from Google to Samsung, many of them have similar methods for accessing the device’s internal IP address. Find “Settings,” and then, select “Connections” or your equivalent. Select WiFi, as it is unlikely that your device is connected to an Ethernet connection, and then, tap the gear icon to the right of the name of your WiFi connection. This should bring up a page of information, including your internal IP address.
• iPhone: Finding the internal IP address for your iPhone is slightly different than for your Apple computer or tablet. Go to “Settings,” tap “WiFi,” and tap the “I” with a circle (indicating “information”), which is to the right of the network you are connected to. This should show your IP address.

References

Internal IP Address. (August 2020). Computer Hope.

What Is My IP Address? (July 2021). Popular Mechanics.

What Is a Private IP Address? (September 2021). LifeWire.

How to Find Your Local and External IP Address. (June 2021). LifeHacker.

A private IP address is a range of non-internet facing IP addresses used in an internal network. Private IP addresses are provided by network devices, such as routers, using network address translation.

Internet Protocol (IP) addresses identify a device on either the internet or a local network. IP addresses also enable information to be sent between devices on a network.

Private IP addresses are commonly used for local area networks in residential, office and enterprise areas. Every device that connects to an internet network -- such as computers, smartphones, tablets or printers -- will have a private IP address. Routers need a way to identify these devices, and the devices may also need to identify each other, which is where private IP addresses come in. Private IP addresses are generated by a router for identification.

Private IP addresses were originally designated to delay the exhaustion of IPv4 addresses -- one of the main types of IP addresses. Originally it was thought that IPv4's 32-bit IP addressing system -- with 4,294,967,296 theoretical IP addresses -- would be adequate for all purposes. But as more internet-connected devices were produced, it became apparent that something had to fill the gap between IPv4 and a future system. Private IP addressing and network address translation began filling that initial gap with a range of private IP addresses. Later, a new addressing system, Internet Protocol Version 6 (IPv6), was introduced. IPv6 increases IP address lengths from 32 bits to 128 bits and is 1,028 times larger than the number of IPv4 addresses.

Private addresses can be assigned by the router using the Dynamic Host Configuration Protocol or be manually set, after which the addresses can communicate with one another through the router.

What is a private IP address used for?

Private IP addresses are commonly used for residential and corporate networks, as the addresses cannot be seen outside the private network. Internet service providers (ISPs) may also allocate a single routable IPv4 address to residential customers. To translate that one address to multiple addresses, so multiple devices can have the assigned address, a network address translator/port address translator gateway is used. This method can connect multiple hosts. 

Corporate networks use private IP addresses for security, since they make it difficult for an external host to connect to a system. Organizations also use private IP addresses to restrict internet access to internal users, which helps increase security.

How can you check your private IP address?

Most individuals do not need to know their IP address, but in some scenarios the knowledge comes in handy, such as when connecting a computer to another device on the network.

The steps for finding a device's IP address differ by platform.

• Windows. Search for cmd in the Windows search bar, then in the command line prompt, type ipconfig to view the private IP address.
• Mac. Select system preferences, then click on network to view the private IP address.
• iPhone. Select settings. Go to Wi-Fi, tap the i that appears next to the network it is connected on, and the IP address will display under the DHCP tab.
• Android. Select Settings, go to About, tap on Status and the IP address should be visible.

Other devices can be checked from the connected router. The steps to do this will differ by router, however.

What are the different private IP address ranges?

Private IP addressing uses both IPv4 and IPv6 addresses.

Private IPv4 addresses have the following class configurations:

• Class A IP addresses. Configurations range from 10.0.0.0 to 10.255.255.255. This class is for large networks and has 8 bits for the network and 24 bits for hosts.
• Class B IP addresses. Configurations range from 172.16.0.0 to 172.31.255.255. This class is for medium networks and has 16 bits for the network and 16 bits for hosts.
• Class C IP addresses. Configurations range from 192.168.0.0 to 192.168.255.255. This class is for smaller networks and has 24 bits for the network and 8 bits for hosts.

The range of private IP addresses seems relatively small because they can be reused on different private networks without consequence. This differs from public IP addresses, which all need to be uniquely identifiable.

IPv6 private address ranges include the following:

• fc00::/7 address block. These are reserved IP addresses from the Internet Assigned Numbers Authority for unique local addresses.
• fec0::/10 address block. These are for deprecating site local addresses.

IPv6 addresses are written in hexadecimal, which uses four bits, meaning an IPv6 address is made up of 32 hexadecimal digits. The numbers are grouped in fours, with a total of eight blocks, or groups.

What are the differences between a private and public IP address?

Both public and private IP addresses have attributes indicative of their roles. For example, differences between public and private IP addresses include how private IP addresses are used for communicating within a private network, or with other devices in a home network or office. They cannot be directly contacted over the internet. Meanwhile, public IP addresses are used to communicate over the public internet, outside a private network. Public IP addresses are unique and cannot be reused unlike private IP addresses, which can be reused. Private IP addresses are assigned to a device by a router within the network, while an ISP assigns public IP addresses. In addition, public IP addresses can be any combination of numbers that do not fall within private IP address ranges.

Private IP addresses also have an extra layer of security because they are only located within private networks, and not to the internet as a public IP address would be.

Learn the differences between IPv4 and IPv6, and how many addresses IPv6 supports.