Finding public IP and private IP and difference

As we all already know if we have read other guides in this blog, the IP address (which stands for Internet Protocol) identifies each computer and device connected to the network. When computers communicate with each other over the Internet or within a local network, they send information and exchange data via their respective IP addresses, which can be thought of as a bit like home addresses. However, since IPv4 addresses (different from IPv6) are made up of 4 numbers separated by a period (such as 192.168.1.1), they cannot be infinite, whoever manages the internet has thought of tying the internet connections of a particular provider to a single public exit IP.The information requested via the internet then first passes through this public IP, which is assigned to a central device capable of sorting the data to private addresses, which are those assigned to computers. Any computer, therefore, it has (probably and unless it has a special connection) a public IP address exposed on the internet and a different one we call private, which is that of the internal network, not visible from other devices on the internet. Let’s see together what are the differences between public IP and private IP and how to find them on our devices connected to the Internet or connected to any type of network.

READ ALSO -> How to Hide the IP Address on PC, Android and iPhone

Difference between public IP and private IP

The main difference between Public IP and Private IP, is that the “Public” is the address of our Internet line (therefore usable also from the outside), while the private IP is managed behind a private network, such as the network generated by a modem or a router. For example, in a typical home network, the central modem has the public IP address on the Internet, while computers, smartphones, game consoles, and other devices connecting from the router all have private and unique IP addresses on the network. The modem then acts as an intermediary and forwards the traffic to the local IP addresses that request it. All devices on the home network communicate with the Internet from a single public IP address, provided by the Internet operator for our line.

Also, as explained in the guide on how we connect to the internet and why with the same Public IP, this public IP can also be shared among multiple subscribers to the same provider.

Guide to private IP address

In a standard configuration each device will then have two IP addresses: the IP address provided by the modem (a private IP address) and a public IP address, which is used to communicate on the Internet.

The private IP in most cases it always starts with numbers 192.168.X.X which is the range of IP addresses specially assigned to private networks. Private IP can also be a static IP, i.e. imposed manually by the user, or dynamic and automatically assigned by the router through the service DHCP. If we have special needs, we can also change IPs on PCs, smartphones and routers. The private IP address is not accessible from the Internet outside the router and without having done a special configuration called Port Forwarding.

Public IP address guide

The public IPinstead, it is assigned directly by the internet provider and can theoretically be used via the internet to connect to our PC from all over the world. For example, if you are hosting a server on your computer, people on the Internet will need to use the router’s public IP address to connect to the server. We explained in another article, focusing mainly on any concerns related to privacy and security, who can see our IP address and what they can do about it.

Also consider that public IP addresses are not necessarily fixed and are almost always dynamic (ie they can change occasionally) unless you request a fixed public IP. For example, as seen in the guide for configure the Fastweb router, you can request and obtain a free fixed public IP from Fastweb.

How to find the private IP address

To find the IP address of a Windows 10 computer all we have to do is press the network icon at the bottom right, click on the item Property and scroll until you find the entry IPv4 address. Another quicker way to find the IP address in Windows is to open the command prompt (we can find it in the Start menu), and run the command ipconfig.

The modem usually has a private IP address of 192.168.1.1 and this address can be used on the web browser to access the configuration screen. From the modem administration page, you can view the public IP address and other information about the Internet connection. In another article we have seen how find the IP address of the home router.

How to find the public IP address

The easiest way to find our public IP address instead, it is to consult a website that automatically detects it. There are several and one, for example, is IPinfo which immediately provides our public IP and also gives us the option to locate the IP. The Whatsmyip site, on the other hand, is also able to tell us what our IPv6 is, if we have assigned one as a public IP.

If we want to hide the public IP address, we invite you to read our guide for falsifying IPs to disguise yourself online.

Conclusions

Understanding the difference between public and private IP addresses will allow us to retrieve only the address we need when we try to access shared folders from a PC or server on the network, or when we try to understand which IP has assigned us the telephony operator. Even if most people live well without knowing this information (in the end it is enough for everything to work), it can be very useful to know it if we are setting up a server on our network or if we want to access a direct remote service, without the use specific programs such as TeamViewer.

Still on the subject of IP addresses, we can read our guides What is an IP address and what is it for and See IP addresses connected to the wifi network from Android or iPhone.
If, on the other hand, we have heard of localhost but do not know what it means, we can find out more by reading the guide What is 127.0.0.1 and what does localhost mean?