Public and private IP addresses are used to identify devices on a network.
Public IP Address:
A public IP address is an address that is assigned to a device that is directly connected to the internet. This address is used to communicate with other devices on the internet. Public IP addresses are unique and globally routable, meaning that they can be accessed from anywhere on the internet.
Private IP Address:
A private IP address, on the other hand, is an address that is assigned to a device on a private network, such as a home or business network. Private IP addresses are not globally routable and are used only within the local network. Private IP addresses are not unique and can be reused on different networks.
The most commonly used private IP address ranges are:
10.0.0.0 – 10.255.255.255 (10.0.0.0/8)
172.16.0.0 – 172.31.255.255 (172.16.0.0/12)
192.168.0.0 – 192.168.255.255 (192.168.0.0/16)
It is important to use private IP addresses on a local network to avoid conflicts with public IP addresses on the internet. Network Address Translation (NAT) is used to translate private IP addresses to public IP addresses when devices on the private network need to communicate with devices on the internet.
IP Version 4 (IPv4):
IP version 4 (IPv4) is the fourth version of the Internet Protocol (IP) that is widely used on the internet. IPv4 uses 32-bit addresses, which are represented as four numbers separated by periods (e.g., 192.168.0.1). Each number in the address can range from 0 to 255, giving a total of approximately 4.3 billion unique addresses.
IPv4 packets consist of a header and a payload. The header contains information about the source and destination addresses, the length of the packet, and other control information. The payload contains the actual data being transmitted.
One of the main challenges with IPv4 is the limited number of available addresses. The explosive growth of the internet has resulted in a shortage of available IPv4 addresses. To address this problem, IPv6 was developed, which uses 128-bit addresses and provides a much larger pool of unique addresses.
However, IPv4 is still widely used today, and various techniques have been developed to extend the lifetime of IPv4 addresses. These include network address translation (NAT), which allows multiple devices on a private network to share a single public IP address, and classless inter-domain routing (CIDR), which allows more efficient use of IPv4 address space by aggregating blocks of addresses.
IP Version 6 (IPv6):
IP version 6 (IPv6) is the sixth version of the Internet Protocol (IP) and is the successor to IPv4. IPv6 uses 128-bit addresses, which are represented as eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). The larger address space of IPv6 allows for approximately 3.4×10^38 unique addresses, which is many times more than the number of available IPv4 addresses.
- IPv6 also includes several new features and improvements over IPv4, including:
- Larger address space: As mentioned, IPv6 provides a much larger address space than IPv4, which enables more devices to connect to the internet and reduces the need for address translation.
- Simplified header: The IPv6 header is simpler and more efficient than the IPv4 header, which can help to reduce processing overhead on network devices.
- Improved security: IPv6 includes support for IPsec, which provides end-to-end encryption and authentication of network traffic.
- Stateless address autoconfiguration: IPv6 devices can automatically configure their own IP addresses without the need for a DHCP server, which simplifies network administration.
- Quality of Service (QoS): IPv6 includes support for QoS, which allows network administrators to prioritize certain types of traffic and ensure that critical applications receive the necessary bandwidth and resources.
Despite these advantages, the adoption of IPv6 has been slow due to the large installed base of IPv4 networks and devices, as well as the costs and complexities involved in transitioning to IPv6. However, as the number of available IPv4 addresses continues to dwindle, the need for IPv6 is becoming increasingly urgent.
