IP addresses

What is an IP address?

IP addresses act as identifiers through which network devices can communicate with each other using the IP protocol and direct packets in the right direction.

IPv4 (Internet Protocol version 4) is originally a developed IP address system that has been widely used for decades. IPv4 addresses consist of 32-bit number groups separated by dots. However, there is a limited number of these addresses, which led to the development of the IPv6 protocol.

For example, the IPv4 address of example.com is 93.184.216.34.

IPv6 (Internet Protocol version 6) is the next generation IP address system designed to replace the limitations of IPv4. IPv6 addresses are 128-bit and are represented as hexadecimal numbers separated by colons. IPv6 provides a vast number of addresses, which better meets the needs of today's network requirements.

For example, the IPv6 address of example.com is 2606:2800:220:1:248:1893:25c8:1946.

IPv4 and IPv6

IPv4 addresses are 32-bit number groups consisting of four octets (8 bits each), separated by periods. For example, 192.168.0.1 is one IPv4 address. This structure allows for the creation of approximately 4.3 billion different IP addresses. Although this number may seem large, the limitation of IPv4 addresses has become problematic as the number of internet users and devices has exponentially increased.

The scarcity of IPv4 addresses is one of the most significant reasons why the IPv6 protocol was developed.

IPv6 addresses are 128-bit and consist of eight groups of four hexadecimal numbers separated by colons. For example, 2001:0db8:85a3:0000:0000:8a2e:0370:7334 is one IPv6 address. This new addressing system allows for approximately 3.4 × 10^38 unique IP addresses, which is a huge number compared to IPv4.

The advantages of the IPv6 protocol are large numbers of addresses, built-in security, and more efficient routing. In addition, IPv6 better supports expanding Internet of Things (IoT) networks, where multiple devices and sensors require their own IP addresses.

Private IP Addresses

Private IP addresses are reserved IP ranges intended for internal networks, such as home or corporate networks. These addresses are not unique globally on the Internet, which means they are not directly routable on the Internet. Instead, they function as identifiers for internal networks and enable local routing of network traffic.

IPv4 private IP ranges

IPv4 protocol has reserved specific private IP address ranges, which are intended for internal networks. This helps to prevent the exhaustion of IP addresses and allows multiple devices to be connected behind a single public IP address.

The most well-known private IPv4 address ranges are as follows:

• 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)

These private IP addresses are reserved for users' internal network needs, such as home networks, business networks, or WLAN networks. They are not directly routable on the Internet and require Network Address Translation (NAT) technology to communicate with publicly routable IP addresses.

IPv6 private IP ranges

There are also reserved specific private IP ranges for the IPv6 protocol. Private IPv6 addresses are defined in the IPv6 Unique Local Address (ULA) registry with an IP range of fc00::/7.

The area is divided into two IP areas fc00::/8 and fd00::/8.

• fc00::/8 is reserved for future use and is not intended to be used at the moment.
• fd00::/8 can be freely used for internal addresses, but the intention is that the end part of the address (40 bits) would be randomly generated. The idea is to obtain internal IP addresses that are globally unique. This way, if two companies connect their networks, there will be no overlapping.

Even internal IPv6 addresses are not routable directly to the Internet.

Test your learning