April 9, 2023

Public and Private IP Addresses – All you need to Know!

With the emerging world of IOT (Internet Of Things), internet connectivity became essential for individuals and businesses alike. This connectivity is made possible by a complex network of interconnected devices that communicate with each other using unique IP addresses. The two types of addresses that are commonly used are public and private IP addresses. In this blog, we will explore what they are, how they work, and their differences.

What is an IP Address?

An internet protocol or (IP) address is a unique identifier assigned to devices that connect to the internet. It comprises a series of numbers separated by dots, e.g., 192.168.0.1. There are two main versions of IP addresses; IPv4, and IPv6 which were invented to overcome the global exhaustion problem of IPv4. Internet Protocol addresses help devices communicate with each other, and without them, the Internet as we know it wouldn’t exist.

Public IP Addresses

A public IP address is a unique identifying address assigned to a device directly connected to the internet. It can be accessed globally and represents the device’s location on the internet, like a virtual street address. Public IP addresses are managed globally by an organization called Internet Assigned Numbers Authority (IANA) which delegates to regional internet registries. Web servers, internet routers, and other devices that are directly connected to the internet are examples of devices that have public IP addresses.

Internet Service Providers (ISPs) or hosting providers assign public IP addresses to devices, and they can change over time. 

Public IP addresses can be static or dynamic. Dynamic IP addresses are temporary and change each time you connect to the internet. However, you can still access the internet while using a dynamic IP address since the device’s previous IP address is replaced with a new one each time you reconnect to the internet.

On the other hand, static IP addresses are permanent and are assigned to a device by the ISP. This address does not change over time and remains the same each time you connect to the internet. Static IP addresses are mostly used by businesses that need accessible remote access to services like a VPN, servers or VOIP.

Private IP Addresses

Contrary to public IP addresses, private IP addresses are only used within a local network, usually located within homes, businesses or organizations. These types of IP addresses are not visible on the public internet, so they don’t have the unique addressability that public IPs have. This means that devices with private IP addresses cannot be accessed from outside the local network.

Private IP addresses are used to create a unique identity for each device within a network. Doing this makes it possible for different devices within the same network to communicate with each other without interference from outside connections. Private IP addresses are typically issued by a router located within the same network as each connected device.

What are the 3 Private IP Address Ranges?

The ranges of private IP addresses are defined by the Internet Engineering Task Force (IETF) and comprise three major ranges:

• 10.0.0.0 to 10.255.255.255
• 172.16.0.0 to 172.31.255.255
• 192.168.0.0 to 192.168.255.255

Private IP addresses help devices connect to the internet indirectly through the router, which assigns each device a unique local IP address that is unique within the network. Therefore, private IP addresses are not considered Internet Protocol (IP) addresses but rather are intranet addresses.

The Main Differences Between Public and Private IP Addresses 

Accessibility 

One of the primary differences between public and private IP addresses is that public IP addresses are accessible from the internet, while private IP addresses are accessible only through their own private network. 

Uniqueness 

Private IP addresses are not globally unique and can be reused on different private networks as they are only visible on a specific network. However, public IP addresses are globally unique and cannot be reused.

Providers 

The other difference is that public IP addresses are provided by internet service providers, while private IP addresses are assigned by a local network.

Address Ranges

Private IP addresses are assigned from specific address ranges, such as 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. In contrast, public IP addresses can be assigned from any available range.

NAT

Network Address Translation (NAT) is a technique used to translate private IP addresses to public IP addresses and vice versa. Private IP addresses are translated to a public IP address when sending data to the Internet, and the public IP address is translated to a private IP address when receiving data from the Internet. NAT allows multiple devices on a private network to share a single public IP address.

In conclusion, both public and private IP addresses play an essential role in Internet communication. That’s why understanding the differences between these two types of IPs is vital for any person or business that seeks to establish and maintain its network.