What does Public IP and Private IP mean? Address - Differences and Usage

Neither the Internet nor macar local computer networks (LAN) could not exist without IPs, and often when we have a problem connecting to the Internet, a print, smart TV or another device, we need to know which is the Public IP address and / or address Private IP. Whether we are talking about IPv4 or IPv6.

What is an IP address and what does IPv4 and IPv6 mean?

I will make a brief and I hope everyone understands a short presentation of what what the IP address means and the two existing versions of IP addresses. IPv4 and IPv6.

IP - Internet Protocol

As I said above, the Internet could not exist without IP addresses (Internet Protocol Address). Every computer, laptop, smart phone, smart TV or any other device that supports internet connection or in a local network, will be identified in it with a unique address, called IP. Through this address the device can communicate and identify with another device or with a network of several devices. Including severers, printers, surveillance systems, smartTVs, smart speakers and more.
The best parallel is with phone numbers. Just as a phone number allows us to communicate with other phones through a unique number, so the IP address allows a computer to communicate with other devices.

IPv4 Vs. IPv6

There are currently two types of IP addresses. IPv4 si IPv6. The latest version, IPv6 appeared more as a necessity, because an IPv4 address consists of four numeric groups (64-bit sequence), up to three digits and a maximum of .255, which limits the number of IP addresses allocated globally. The need for IP addresses being much higher than IPv4 could provide, that is, approximately 4.3 billion addresses, in 1996 IPv6 appeared. Developed by the Internet Engineering Task Force (IETF), the new version supports up to trillions, trillions, trillions of combinations, being made up of a 128-bit sequence. The number of stations that can receive IPv6 can be said to be astronomical and will never be reached. To the number 340 we add 36 zeros to get the total number supported by IPv6.

IPv6 can be of three types: unicast, anycast and multicast.

  • IPv6 Multicast - Identifies a group of interfaces so that the packet sent from the interface is delivered to all interfaces in the group.
  • IPv6 Anycast - Similar to the multicast with the difference that from the group to which the data is sent the nearest interface is identified.
  • IPv6 Unicast - A single source will send data to a single interface.

IPv6 has no broadcast, but this feature is multicast.

It is good to know that IPv4 and IPv6 can only communicate directly with each other through a server.

Example IPv4 address: 162.160.2.1 (four numeric groups - 32-bit)
Example IPv6 address: 2001:0db8:85a3:0000:0000:8a2e:0370:7334 (eight hexadecimal / 128-bit groups)

In addition to IPv4 and IPv6, IP addresses can be classified into two categories. Private IP si Public IP.

Private IP si Public IP - What they are and what are the differences between them

A computer or other device connected to the Internet will have two types of IPs:

  • Private IP - the one through which it will communicate exclusively with the devices from the Local Area Network (LAN)
  • Public IP - the IP address through which the device communicates with other devices on the Internet. Including websites, online applications, online games, online movie platforms, sharing services and more.

What does Private IP mean?

When we connect with a device (computer, phone, laptop, etc.) to a router, it automatically assigns us a local IP, through which our device can communicate with other devices in the network. This Local IP, is also called Private IP. So, this is an IP assigned to a device from Local Area Network (LAN).
The local IP address is unique for each device on the network, and this IP cannot be used to connect to the Internet. Any data packets supported by network devices can be transmitted and received, in a secure environment, without interaction outside the local network.

What does Public IP mean?

The public IP address (or Public IP) is the one through which your device identifies itself on the internet, when you access websites, online applications of services that require an Internet connection.
Public IP is assigned by your Internet Service Provider (ISP) and can be set up on a router / modem to share internet connection with multiple devices on the local network. To see what the public IP address of your device is, just search on Google "what is my IP address”And without the need to access another web page, Public IP will appear. It can be IPv4 or IPv6.

The public IP address is also unique for each source, but here the definition of "source" is actually the router on which it was set. So if you have a smart TV, laptop, computer, smart phone in the house, all this they will have the same public IP address on the internet. Exceptions are devices for which you request a dedicated IP from the provider, which will be configured manually.

Passionate about technology, I like to test and write tutorials about operating systems macOS, Linux, Windows, about WordPress, WooCommerce and LEMP web server configuration (Linux, NGINX, MySQL and PHP). I write on StealthSettings.com since 2006, and a few years later I started writing on iHowTo.Tips tutorials and news about devices in the ecosystem Apple: iPhone, iPad, Apple Watch, HomePod, iMac, MacBook, AirPods and accessories.

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