What is IP address, private IP address, public IP address?

IP address

An IP(Internet Protocol) address is a unique address that identifies a computer or device on the internet. It stores information about device location and allows devices to connect with one another as a result. A device or computer must have an address or a unique mechanism by which another device may locate the relevant device for communication to send or receive data, and this is done with the help of an IP address, which distinguishes different computers, routers, or devices on a network.

There are two types of IP address

  • IPv4: IP version 4(IPv4) is a 32-bit address that contains a set of four numbers each separated from the next by a period(.). Each number in the set can range from 0 to 255.  As a result, the entire IP addressing range is to
  • IPv6: IP version 6(IPv6) is a 128-bit address that consists of eight groups of four hexadecimal digits, with each group separated by colons(:).An example of an IPv6 address is 2011:0db8:76c5:0000:0000:7bd4:071e:8394.

Classification of IP address

Private IP Address:

  • Each device on the same network is allocated a unique private IP address, allowing devices on the same internal network to communicate with one another.
  • As the number of internet-connected devices grows, private IP addresses give an altogether different set of addresses that allow access to a network without taking up public IP address space.
  • A router assigns private IP addresses to devices so that they can connect to other devices on the same network safely.
  • Because private addresses are not routed across the Internet and no traffic may be sent to them from the Internet, they provide an extra layer of protection.

  Public IP Address:

The ISP (Internet Service Provider) assigns a public IP address, which is used to access the Internet. A device’s public IP address is used to identify it on the internet and to connect with it outside of the network.

A public IP address can be further classified as

  • Dynamic IP Address: An IP address that changes from time to time and isn’t always the same is known as a dynamic IP address. Internet Service Providers (ISPs) provide dynamic IP addresses to devices attempting to connect to the internet.
  • Static IP Address: Static IP addresses are addresses that do not change after they have been assigned to a device. Servers and other key equipment typically utilize static IP addresses.


  • Automatic Private IP Addressing (APIPA) is a feature in operating systems (such as Windows) that enables a computer to automatically assign itself an IP address from the APIPA range when  DHCP(Dynamic Host Configuration Protocol) server is either permanently or temporarily unavailable. APIPA is only valid within a local network segment or subnet.
  • The Internet Assigned Numbers Authority (IANA) has set aside the range for Automatic Private IP Addressing, with a subnet mask.
  • If a DHCP server becomes available later, the APIPA address is changed to the DHCP server’s address.
  • To confirm that the specified address is not already in use by another network computer, the client employs Address Resolution Protocol (ARP).