IPv4 vs. IPv6 – Definitions and Differences

By Staff Contributor on May 5, 2023

As we become more dependent on the internet, we need to better understand the technologies that make it possible. One of these technologies is the IP address or Internet Protocol address. IP addresses are used to uniquely identify devices on the internet, allowing them to communicate with each other. In this post, we will discuss the two most commonly used versions of IP addresses: IPv4 and IPv6.

What Is an IP Address?

What Is IPv4?

Features of IPv4

IPv4 Exhaustion and Solutions

What Is IPv6?

Features of IPv6

Differences between IPv4 vs IPv6

Advantages of IPv6 to IPv4

IPv4 vs IPv6 Speed

Reserved Ranges

Conclusion

What Is an IP Address?

An IP address is a unique identifier assigned to every device connected to the internet. They come in two forms, IPv4 and IPv6. In addition to identifying devices, IP address allow devices to communicate with each other by routing data packets to their intended destination. Data packets are the units of information used to transmit data across networks, such as the internet or local area networks (LANs). When a device sends data to another device, the data is broken up into packets. Each packet is sent separately and contains the sender’s IP address and the recipient’s IP address, as well as other information needed for the data to be correctly delivered. Routers on the network use IP addresses to forward packets to their intended destinations.

IP addresses can be either static or dynamic. A static IP address is manually assigned to a device and remains the same over time. Static IP addresses are typically used for devices that need a permanent IP address. On the other hand, a dynamic IP address is assigned by a DHCP (Dynamic Host Configuration Protocol) server and can change over time, which is a helpful feature for gadgets that don’t require a fixed IP address, such as laptops or smartphones.

What Is IPv4?

IPv4 is the fourth version of the Internet Protocol and the internet’s most widely used IP protocol. It uses a 32-bit address space and can support up to 4.3 billion unique IP addresses. IPv4 addresses are represented in dotted decimal notation, such as 192.168.1.1.

Features of IPv4

IPv4 has several features that make it suitable for use on the internet. One of its main advantages is its simplicity, which makes it easy to implement and manage. It also supports many devices, from desktop computers to mobile phones and IoT devices. Additionally, IPv4 includes features such as fragmentation, which breaks large data packets into smaller pieces for more efficient transmission.

IPv4 Exhaustion and Solutions

The popularity of the internet and the explosion of connected devices has led to the exhaustion of IPv4 addresses. This means that no more unique IPv4 addresses are available to be allocated to new devices. IPv4 uses a 32-bit address space, which provides only around 4.3 billion unique IP addresses. With the increasing number of internet-connected devices, the available pool of IPv4 addresses was quickly depleted.

To address this issue, technologists have proposed various solutions:

  • Network Address Translation (NAT), which allows multiple devices to share a single public IPv4 address. NAT works by assigning a unique private IP address to each device on a local network and then translating these private addresses to the public IPv4 address when a device sends data outside the local network. This system allows many devices to share a single IPv4 address, effectively extending the life of the IPv4 address space.
  • Classless Inter-Domain Routing (CIDR), which allows more efficient use of the available IPv4 address space. CIDR allows a single IPv4 address to be divided into smaller subnets, each with its unique network prefix. These subnets allow for a more granular allocation of IP addresses and reduce the waste of address space.
  • IPv6 offers a much larger address space than IPv4, with 128-bit addresses that provide around 3.4 x 10^38 unique IP addresses. IPv6 also includes other improvements over IPv4, such as better support for mobile networks and improved security features. However, the transition to IPv6 could have been faster due to the need for infrastructure upgrades and the complexity of transitioning to a new protocol.

What Is IPv6?

IPv6 is the sixth version of the Internet Protocol and is designed to address the limitations of IPv4. It uses a 128-bit address space and can support up to 3.4 x 10^38 unique IP addresses. IPv6 addresses are typically represented in hexadecimal notation, such as 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

Features of IPv6

IPv6 has several features that make it suitable for use on the internet. One of its main advantages is its ample address space, which allows for an almost unlimited number of unique IP addresses. With IPv6, we don’t need NAT and CIDR, so it’s easier to manage networks. IPv6 also includes features such as auto-configuration, which allows devices to configure their IP address and network settings automatically.

Differences between IPv4 vs IPv6

IPv4 and IPv6 differ in several ways, the most obvious being the size of their address spaces. While IPv4 uses a 32-bit address space, IPv6 uses a 128-bit address space. This means that IPv6 can support significantly more unique IP addresses than IPv4. Additionally, IPv6 includes several features not present in IPv4, such as flow labeling, which allows for more efficient packet forwarding, and extension headers, which provide additional information about the transmitted data.

Advantages of IPv6 to IPv4

IPv6 offers several advantages over IPv4, including:

  1. Simplified network management: IPv6 includes several features that simplify network management. For example, IPv6 includes auto-configuration, which allows devices to automatically configure their IP addresses and network settings without manual configuration. This makes it easier to manage large networks and reduces the risk of configuration errors.
  2. Improved security: IPv6 includes several security features not present in IPv4. For example, IPv6 natively supports IPsec (Internet Protocol Security), providing secure communication between devices on a network. IPv6 also includes features such as neighbor discovery, which detects and prevents address spoofing attacks.
  3. Better support for mobile networks: IPv6 works seamlessly with mobile networks, which are increasingly important today due to several factors, including the growing demand for connectivity, proliferation of smart devices, reliance on mobile applications, expansion of Internet of Things (IoT) ecosystems, need for remote work and learning, and the pursuit of digital inclusivity. As technology continues to evolve and people become more reliant on mobile devices for various aspects of their lives, mobile networks play a crucial role in ensuring seamless communication, data exchange, and access to information and services. IPv6 includes mobility management features, allowing devices to maintain their IP addresses even when they move between networks. This is particularly important for mobile devices such as smartphones and tablets.
  4. Better support for multicast traffic: IPv6 provides better support for multicast traffic, which is used for streaming media and other collaborative applications. Multicast traffic allows data to be sent to multiple devices simultaneously, which is much more efficient than sending the data separately to each device. IPv6 includes features such as multicast listener discovery, which lets devices discover and join multicast groups.

IPv4 vs IPv6 Speed

When it comes to speed, IPv6 has the potential to be faster than IPv4. This is because IPv6 includes features such as larger packet sizes and more efficient packet forwarding, which can improve network performance. However, the actual speed of a network depends on many factors, such as network topology, hardware, and the amount of traffic on the network. Nevertheless, the speed of IPv4 and IPv6 networks should be comparable.

Reserved Ranges

Reserved ranges refer to specific blocks of IP addresses that are set aside by the Internet Assigned Numbers Authority (IANA) and regional registries for special purposes. These ranges are not assigned to any organization for general use, and they serve unique functions.

Common Reserved Ranges

Some of the most common reserved ranges include:

  1. Private IP addresses: These addresses are reserved for use within private networks, such as home, office, or enterprise networks. They are not routable on the public internet, which means that traffic originating from these addresses cannot be directly sent to or received from the internet. Network Address Translation (NAT) is used to translate private IP addresses to public IP addresses when communicating with the internet. In IPv4, the private IP address ranges are:
    1. 10.0.0.0 to 10.255.255.255 (10.0.0.0/8)
    1. 172.16.0.0 to 172.31.255.255 (172.16.0.0/12)
    1. 192.168.0.0 to 192.168.255.255 (192.168.0.0/16)

In IPv6, the reserved private address range is:

  • fc00::/7 (includes addresses starting with “fc” and “fd”)
  • Loopback addresses: These addresses are used for testing and internal communication within a device. In IPv4, the loopback address range is 127.0.0.0 to 127.255.255.255 (127.0.0.0/8), with the most commonly used loopback address being 127.0.0.1. In IPv6, the loopback address is ::1.
  • Link-local addresses: These addresses are used for local communication within a network segment, such as for auto-configuration or neighbor discovery. They are not routable beyond the local network segment. In IPv4, the link-local address range is 169.254.0.0 to 169.254.255.255 (169.254.0.0/16). In IPv6, the link-local address range is fe80::/10 (includes addresses starting with “fe80”).
  • Multicast addresses: These addresses are used to send packets to multiple recipients simultaneously. In IPv4, the multicast address range is 224.0.0.0 to 239.255.255.255 (224.0.0.0/4). In IPv6, the multicast address range is ff00::/8 (includes addresses starting with “ff”).

There are other reserved ranges as well, but these are some of the most common ones. Each reserved range serves a specific purpose within the context of IP networking and enables certain network functions and features.

Conclusion

IP addresses are essential for enabling communication between devices on the internet. While IPv4 has been the dominant IP protocol for many years, its address space has been exhausted, leading to the development of IPv6. IPv6 offers several advantages over IPv4, including a larger address space and improved network management and security features. As the internet continues to evolve, it is essential to stay up to date with the latest technologies and protocols to ensure the smooth operation of our networks.

This post was written by Juan Reyes. As an entrepreneur, skilled engineer, and mental health champion, Juan pursues sustainable self-growth, embodying leadership, wit, and passion. With over 15 years of experience in the tech industry, Juan has had the opportunity to work with some of the most prominent players in mobile development, web development, and e-commerce in Japan and the US.

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