Introduction

The evolution of the internet has led to an unprecedented growth in the number of devices connected to the web. Every device that connects to the internet is assigned a unique Internet Protocol (IP) address, which serves as a unique identifier, enabling communication and data transfer between devices. IP addresses can be categorized into two main types: public and private. While both types of IP addresses serve critical roles in the functioning of the internet, they differ in several key aspects. This article presents a comprehensive comparative analysis of public and private IP addresses, highlighting their similarities, differences, and respective use cases.

http://deepweb.net/blog/newest/public-vs-private-ip-address

Public IP Addresses: An Overview

A public IP address is a unique identifier assigned to a device or network of devices that connect to the internet. Public IP addresses are globally unique and are managed by the Internet Assigned Number Authority (IANA), which allocates blocks of IP addresses to Regional Internet Registries (RIRs). RIRs, in turn, assign these blocks to internet service providers (ISPs), who then allocate them to end-users. Public IP addresses are reachable over the internet, and any device can initiate communication with a device that has a public IP address. Public IP addresses can be either static or dynamic. Static IP addresses remain constant over time, while dynamic IP addresses change periodically.

Private IP Addresses: An Overview

In contrast to public IP addresses, private IP addresses are used for communication within a local network or intranet. Private IP addresses are not globally unique and are not assigned by IANA or RIRs. Instead, they are assigned by network administrators and are not reachable over the internet. Private IP addresses are typically used in home and business networks, where multiple devices share a single internet connection. Private IP addresses are defined in three ranges by the Internet Engineering Task Force (IETF): 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.

Public vs Private IP Addresses: Similarities and Differences

One of the most significant differences between public and private IP addresses is their scope of use. Public IP addresses are used for communication between devices over the internet, while private IP addresses are used for communication within a local network. Public IP addresses are globally unique, while private IP addresses are not. Public IP addresses are managed by IANA and RIRs, while private IP addresses are assigned by network administrators.

Another critical difference between public and private IP addresses is their visibility over the internet. Public IP addresses are reachable over the internet, while private IP addresses are not. This difference has significant implications for network security. Since private IP addresses are not reachable over the internet, they are less vulnerable to external threats than devices with public IP addresses. However, devices with private IP addresses can still be compromised if an attacker gains access to the local network.

Public and private IP addresses also differ in their use of Network Address Translation (NAT). NAT is a technique used to conserve the limited supply of public IP addresses by allowing multiple devices with private IP addresses to share a single public IP address. NAT enables devices with private IP addresses to communicate with devices over the internet by translating their private IP addresses to the public IP address of the network.

Public vs Private IP Addresses: Use Cases

Public IP addresses are essential for devices that provide services over the internet, such as web servers, email servers, and FTP servers. Devices that require direct access from the internet, such as Virtual Private Network (VPN) servers, also require public IP addresses.

Private IP addresses are commonly used in home and business networks, where multiple devices share a single internet connection. Private IP addresses are also used in large organizations with complex network architectures, where devices are organized into subnets.

Conclusion

In conclusion, public and private IP addresses serve critical roles in the functioning of the internet. Public IP addresses are globally unique, reachable over the internet, and are used for communication between devices over the internet. Private IP addresses, on the other hand, are used for communication within a local network, are not reachable over the internet, and are assigned by network administrators. Understanding the differences between public and private IP addresses is essential for network administrators, cybersecurity professionals, and anyone interested in the functioning of the internet.