Last Updated on August 3, 2023 by Mayank Dham
In the vast world of computer networking, IP addresses play a crucial role in identifying and communicating with devices on the internet. Every device connected to a network is assigned a unique IP address, which serves as its digital identifier. IP addresses can be broadly categorized into two types: private IP addresses and public IP addresses.
Understanding the difference between private and public IP addresses is essential for network administrators, IT professionals, and anyone curious about how devices communicate across the internet. Private IP addresses are used within local networks, such as home or office networks, to facilitate internal communication, while public IP addresses are assigned by Internet Service Providers (ISPs) to enable devices to communicate with each other over the internet. Let’s see the difference between private qand public IP addresses.
What is a Private IP address?
A Private IP address is an IP address that is used within a private network, such as a home or office network, to identify and communicate with devices within that network. These addresses are not directly accessible over the internet, and they are reserved for internal use only. Private IP addresses are assigned by the network administrator and are not unique globally; multiple networks can use the same private IP address ranges without any conflict.
There are three ranges of private IP addresses defined by the Internet Assigned Numbers Authority (IANA):
- 10.0.0.0 to 10.255.255.255 (10.0.0.0/8)
- 172.16.0.0 to 172.31.255.255 (172.16.0.0/12)
- 192.168.0.0 to 192.168.255.255 (192.168.0.0/16)
Private IP addresses enable devices within a local network to communicate with each other and share resources like printers, files, and internet access through a router or gateway. When devices from a private network need to communicate with devices on the internet, Network Address Translation (NAT) is used to translate the private IP address to a public IP address assigned by the Internet Service Provider (ISP). This process allows private networks to share a single public IP address and effectively extends the use of IPv4 addresses, which are limited in number.
What is a Public IP address?
A Public IP address is an IP address that is globally unique and used to identify and communicate with devices over the internet. It is assigned to a device by the Internet Service Provider (ISP) and serves as the device’s public-facing digital identifier on the worldwide web.
Devices with public IP addresses can communicate directly with other devices across the internet. They are accessible from anywhere on the internet, allowing users to access web servers, send emails, make video calls, and perform various online activities. Public IP addresses are essential for hosting websites, online gaming, video streaming, and other internet-based services that require direct communication with external devices.
Unlike private IP addresses, public IP addresses are not reserved and must be unique to avoid conflicts. With the growing number of internet-connected devices, the depletion of available IPv4 addresses has become a concern. To address this issue, IPv6 was introduced, which provides a much larger address space to accommodate the increasing number of devices.
Difference between Private and Public IP address:
Let’s see the tabular representation of the difference between Private and public IP addresses.
| S.No. | PRIVATE IP ADDRESS | PUBLIC IP ADDRESS |
|---|---|---|
| 1. | The scope of Private IP is local. | The scope of Public IP is global. |
| 2. | It is used to communicate within the network. | It is used to communicate outside the network. |
| 3. | Private IP addresses of the systems connected in a network differ in a uniform manner. | Public IP may differ in a uniform or non-uniform manner. |
| 4. | It works only on LAN. | It is used to get internet service. |
| 5. | It is used to load the network operating system. | It is controlled by ISP. |
| 6. | It is available free of cost. | It is not free of cost. |
| 7. | Private IP can be known by entering “ipconfig” on the command prompt. | Public IP can be known by searching “what is my ip” on google. |
| 8. | Private IP uses numeric code that is not unique and can be used again | Public IP uses a numeric code that is unique and cannot be used by other |
| 9. | Private IP addresses are secure | Public IP address has no security and is subjected to attack |
| 10. | Private IP addresses require NAT to communicate with devices | Public IP does not require a network translation |
Let’s discuss the key points related to the difference between Private and Public IP addresses.
1. Definition:
Private IP Address: A Private IP address is used within a local network, such as a home or office network, to facilitate internal communication among devices within that network. It is not accessible over the internet and is reserved for private use only. Private IP addresses are not unique globally, and multiple networks can use the same ranges without conflict. The most commonly used private IP address ranges are 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255.
Public IP Address: A Public IP address is globally unique and is assigned to a device by the Internet Service Provider (ISP). It serves as the public-facing digital identifier of the device on the internet. Devices with public IP addresses can communicate directly with other devices across the internet and are accessible from anywhere on the web.
2. Scope and Accessibility:
Private IP addresses are confined within a local network and are used for communication among devices within that network. They are not directly accessible from the internet.
Public IP addresses are accessible from anywhere on the internet and enable devices to communicate with each other globally. They allow users to access web servers, send emails, make video calls, and perform various online activities.
3. Uniqueness:
Private IP addresses are not globally unique, and the same private IP address ranges can be used in multiple private networks without conflict.
Public IP addresses must be globally unique to avoid conflicts. Each public IP address can only be assigned to one device at a time.
4. Assignment:
Private IP addresses are assigned by the network administrator within a private network, typically through a router or gateway.
Public IP addresses are assigned by the Internet Service Provider (ISP) to each device connected to the internet.
5. Communication with the Internet:
Devices with private IP addresses require Network Address Translation (NAT) to communicate with devices on the internet. NAT translates the private IP address to the public IP address assigned by the ISP, enabling internet communication.
Devices with public IP addresses can communicate directly with other devices on the internet without the need for translation.
6. Use Cases:
Private IP addresses are used within local networks to facilitate internal communication, resource sharing, and private data exchange. They are commonly used in homes, offices, and educational institutions.
Public IP addresses are essential for hosting websites, online gaming, video streaming, and other internet-based services that require direct communication with external devices.
7. IPv4 and IPv6:
IPv4 is the current version of the Internet Protocol and is used for both private and public IP addresses. However, IPv4 addresses are limited, and the increasing number of internet-connected devices has led to the depletion of available IPv4 addresses.
IPv6 was introduced to address the scarcity of IPv4 addresses. It provides a significantly larger address space, allowing for more unique IP addresses and accommodating the growing number of devices connected to the internet.
Conclusion
In conclusion, the difference between Private and Public IP addresses lies in their scope, accessibility, uniqueness, and use cases. Private IP addresses are reserved for internal communication within local networks, while Public IP addresses are globally unique and enable devices to communicate directly across the internet. The proper understanding and management of these two types of IP addresses are critical for maintaining efficient and secure network infrastructures in the ever-evolving digital landscape. As technology continues to advance and more devices connect to the internet, the significance of IP address management becomes increasingly paramount for a seamless and interconnected world.
FAQs on Difference between Private and Public IP Address:
Here are a few FAQs on the difference between private and public IP addresses.
1. What is a Private IP address, and where is it used?
A Private IP address is used within a local network, such as a home or office network, to facilitate internal communication among devices within that network. It is not accessible from the internet and is reserved for private use only.
2. How are Private IP addresses assigned?
Private IP addresses are assigned by the network administrator within a private network, typically through a router or gateway. The most commonly used private IP address ranges are 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255.
3. What is a Public IP address, and what is its purpose?
A Public IP address is globally unique and assigned by the Internet Service Provider (ISP) to a device. It serves as the public-facing digital identifier of the device on the internet and enables direct communication with other devices globally.
4. Are Private IP addresses unique globally?
No, Private IP addresses are not globally unique. The same private IP address ranges can be used in multiple private networks without conflict.
5. How do devices with Private IP addresses communicate with the internet?
Devices with Private IP addresses require Network Address Translation (NAT) to communicate with devices on the internet. NAT translates the Private IP address to the Public IP address assigned by the ISP, enabling internet communication.