Private and Public IP Address: What Are They and Their Differences

Without the IP address ( Internet Protocol ) it would be impossible to browse the Internet, since this unique number, which is assigned to each device that connects to the Internet, is essential so that they can communicate with each other (it is how our postal address to receive letters physical). Also, there are two types of IP addresses: Private IP and Public IP . In this article we will see what each of them is and what functions they fulfill.

Public IP Address What is it?

A public IP address is one that is assigned to any device that connects directly to the Internet, for example, the home router or the servers where the web pages are hosted. The public IP is visible from the Internet.

The public IP is a unique address and can never be repeated. It is assigned by Internet providers (ISP) and is also known as a dynamic IP address , since it changes every time we restart the router or every certain period of time. This means that there is also a fixed or static public IP address , but if it is needed for any reason, it is necessary to contact the ISP to request that they configure it manually for us.

Private IP Address What is it?

The private IP address is a fixed address that is assigned to each device connected to a private or home network, that is, the IP address that the router assigns to each computer, smartphone, smart TV, tablet, game console or any other device connected to he. Thus, each device connected to a router has its own private IP address, while sharing the same public IP.

Private IP’s are not accessible from the Internet and do not change, unless we assign them manually.

Private IP ranges

Within the private IPs we can find different ranges, which are assigned depending on the type of network:

Class A range

The class A range is the one used by large companies, since it allows you to create up to 126 different networks and connect up to a maximum of 16,777,214 computers to the network.

This range is between these numbers: to . The first block of the address identifies the network and the other three blocks identify the devices that connect to the network.

Class B range

The class B range is used in medium-sized networks, such as organizations or universities. It allows you to create a greater number of networks than range A, 16,384 networks, but with much less equipment connected to them, 65,534 devices.

The range is from to ; the first two blocks identify the network and the rest identify the computers connected to it.

Class C range

Finally, the class C range is the most common and used, since it is the one used in home networks. It allows to have many more networks, 2,097,152, but being able to connect much less equipment to each of them, 254.

Range C is from to ; here it is the first three blocks that identify the network, while the last one identifies the equipment.

Public IP address range

Public IP addresses also have ranges and correspond to those that are excluded from the ranges for private IPs, going from “1. …” to “191. …». So the range of the public IP will be in:

  • Class A: to
  • Class B: to
  • Class C: to

How are public and private IP addresses different?

We have already advanced it, the main differences between public IP and private IP is that the first is accessible from the Internet and the second is not, and that the first is assigned to the point of connection and access to the Internet (the router) and the second to the devices connected to that endpoint.

Apart from this, more than talking about the differences between private and public IP , we can say that without the second, the computers connected to a private network could not connect to the Internet, that is, to be able to surf the Net it is necessary to have an IP assigned public (to understand it we can use the simile of the car’s license plate, without it you can’t take the car out on the road, because the same thing happens on the Internet, without a public IP address you can’t go surfing in cyberspace).

How to see my private IP?

Now that we know what a private IP and a public IP are, how can I know my private IP ? Is there a way to see my private IP ? The answer is yes, it can be done from the computer itself.

  • Know my private IP in Windows:
    • Press the Windows symbol key + R
    • Type CMD in the box and press enter
    • The command prompt will appear, here you must type ipconfig and press enter
    • In the result, look for the line that includes “IPv6 address” and “IPv4 address”, the numbers that appear there are your private IP addresses.
  • Know my private IP on Mac:
    • Click on the magnifying glass to the right of the operating system
    • In the search box type “Terminal” and press enter
    • In terminal type ifconfig and hit enter
    • In the result look for “inet6” and “inet”, the numbers that appear there are your private IP addresses.
  • Know my private IP in Linux:
    • Press the Control + Alt + T keys
    • In the terminal type ifconfig and press enter
    • Search the result for “inet” and “inet6” to find out your private IP numbers.

What is my public IP?

To see the public IP there are many web pages that just by entering them will tell you. One of the most popular is, as soon as you access it it will show you your public IP address, along with your ISP and the possibility of geolocating it.

Does that mean that my IP can be located geographically ? Yes, but with nuances, the geolocation of the IP will be approximate, because the address it locates is the address of our ISP, which is the one who assigns us the public IP address (as we said at the beginning), so our physical address does not will be visible.

How to change IP from public to private?

You cannot change the public IP to private, as we have said, without a public IP you cannot browse the Internet. But what you can do is hide the public IP when you browse, how? Using a VPN.

When using a virtual private network (VPN), the public IP assigned to you by your ISP is hidden by the IP assigned to you by the VPN, so that if a website wants to track your IP address, it will not be able to do so, because it will be following that of the VPN.

The above content published at Collaborative Research Group is for informational purposes only and has been developed by referring to reliable sources and recommendations from experts. We do not have any contact with official entities nor do we intend to replace the information that they emit.

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