IPv4 vs IPv6: How do the Two Versions of IP Differ?


Internet Protocol or IP is what makes it possible to send data from one computer or device to another over the web. In this article, we will discuss IP, IPv4, IPv6, and IPv4 vs IPv6.

What is IP?

The internet protocol is represented by an IP address. Each device connected to a network is given an IP address. For communication, each device has an IP address. It also serves as an identifier because this address is used to identify a device on the network.

It specifies the technical format of data packets. TCP/IP refers to both the IP and TCP protocols combined. It establishes a virtual link between the origin and the destination.

An IP address can alternatively be defined as a numerical address assigned to each device on a network. Each device on a network is given an IP address, which allows it to be uniquely identified. The TCP/IP protocol utilizes a 32-bit logical address known as IPv4 to simplify packet routing.

An IP address is made up of two components, the first of which is a network address and the second of which is a host address. IP addresses are divided into two categories, namely IPv4 and IPv6.

What is IPv4?

IPv4 is the fourth version of IP, and it defines the rules for computer networks that run on the packet exchange concept. Through an addressing scheme, it may uniquely identify devices connected to the network.

When a device connects to the internet (whether it’s a switch, a PC, or something else), it’s given a unique numerical IP address, such as IPv4 has a 32-bit address system that allows for the storage of 232 hosts (4.19 billion addresses).

As the number of people connected to the internet grows, IPv4 addresses become scarce. To meet the demand for more IP addresses, a new IP addressing system, IPv6, was introduced.

IPv4 Characteristics

  • It is a protocol without connection.
  • It allows for the creation of a simple virtual communication layer across a variety of devices.
  • IPv4 requires less memory and makes recalling addresses easier.
  • Millions of gadgets now support the protocol.
  • Video libraries and conferences are available.

What is IPv6?

In 1999, IPv6 (Internet Protocol Version 6) was implemented in response to concerns that the demand for IP addresses might outstrip the supply. It facilitates communication and data transfer through a network.

IPv6 is a 128-bit internet address that can hold a total of two 128 addresses. IPv6 addresses not just fix the issue of limited network address resources, but also overcome the hurdles faced by access devices connecting to the Internet. An IPv6 address can look like this:


IPv6 Characteristics

  • Infrastructure for hierarchical addressing and routing.
  • Configurations with and without states.
  • Support for service quality (QoS).
  • An optimal approach for interacting with neighbors.

IPv4 vs IPv6

A 32-bit address space constraints IPv4, limiting the number of distinct hosts to 232. This translates to around 4.3 billion IPv4 addresses.

The global coordinator of IP addressing, the Internet Assigned Numbers Authority (IANA), ran out of free IPv4 address space to give to regional registries in 2011.

IANA then generated a recovered address pool by recovering extra unused IPv4 address blocks from regional registries. IANA declared in 2014 that it was redistributing the recovered address pool’s final addresses. There will be no more IPv4 addresses after it is tapped.

The internet has been gradually transitioning to IPv6 to address this issue. The IPv6 protocol was first announced in 1998 by the Internet Engineering Task Force to eventually replace IPv4’s 32-bit addresses with 128-bit addresses.

Unlike IPv4 addresses, IPv6 addresses are composed of four hexadecimal digits separated by colons (using digits 0-9 plus letters A-F) (e.g., 2002:db8::8a3f:362:7897). Controlling IP address allocation is essential.

Can you picture the turmoil if someone else got your phone number as well? A similar issue affects devices linked to an IP network. For good reason, every networked device has its own IP address. You don’t want your emails to end up in the wrong hands since the mail server’s IP address has been duplicated.

While the Domain Name System (DNS) may detect duplicate IP addresses, the time and effort required to resolve issues on a regular basis necessitate tight allocation control from a single coordinating entity.

IPv4 vs IPv6: A Comparison Table

IPv4 vs IPv6: Difference Table




AddressIt uses a 32-bit address in the decimal form.IPv6 uses a 128-bit address in the hexadecimal form.
ChecksumIt requires a checksum field.There is no need for a checksum field in IPv6.
EncryptionIPv4 does not have any encryption feature.It comes with encryption.
FragmentationIn IPv4, sender and forwarding routes perform fragmentation.Only the sender performs fragmentation in IPv6.
Header fieldsIPv4 has 12 header fields and the field length is 20.It has 8 header fields with a field length of 40.
MAC address mappingIt uses ARP (Address Resolution Protocol) for mapping MAC addresses.IPv6 uses NDP (Network Discovery Protocol) to map MAC addresses.
Mobile device compatibilityIt is not ideal for mobile devices.It is compatible with mobile devices.
Optional fieldsIPv4 comes with many optional fields.No optional field is available with IPv6.
SecurityGood.Better than IPv4.
Total address generation4.3 billion3.4×1038
VLSM (Virtual Length Subnet Mask) supportAvailable.Not available.

The Need for IPv6

IP addressing is a logical method of allocating addresses to network devices. A unique IP address is required for each device connected to the internet or intranet.

The internet protocol suite contains IP as well as the transmission control protocol (TCP). The internet protocol suite describes how data is packetized, addressed, sent, routed, and received via the internet.

The most popular format for IPv4 addresses is x.x.x.x, where each x can be any integer between 0 and 255, often known as dotted quad or dotted decimal. Periods are used to separate these values. An example of a valid IPv4 internet address is

On the surface, it appears that 4.3 billion distinct IPv4 addresses are sufficient. However, it is not. The average number of connected devices per household in 2020, according to TechJury’s IoT roundup, was 10.

Phones, printers, laptops, tablets, appliances, and IoT gadgets like smart doorbells and security cameras all fall under this category. Each of these needs its own IP address.

Some estimates state that the number of linked devices will reach 46 billion by the end of 2022. That’s more than ten times the maximum IPv4 address.

It can be costly to obtain one of the few remaining IPv4 addresses. According to a study on the cost of IPv4 addresses, the price per address from a legal marketplace in 2020 was $36. (There’s also an IPv4 black market.) Crooks dupe registries into transferring IPv4 block ownership to them, which they subsequently resale at inflated prices.)

Nobody purchases just one. Even if you can buy a block, there aren’t enough IPv4 addresses to go around for all of the devices that require one. Thus, eventually, IPv6 is required.

The Advantages of Switching from IPv4 to IPv6

Apart from being the most recent version of the internet protocol, IPv6 has various other advantages that make migrating a sensible option. IPv6 has a substantially bigger address space, is less complicated, and is faster (in theory at least).

IPv6 allows for 2128, or nearly 340 undecillion, unique addresses, compared to IPv4’s 4,294,967,296 (232). Devices with private addresses must use a sophisticated and resource-intensive workaround known as network address translation to access the public internet. A NAT gateway converts outgoing traffic’s internal address to its public IP address.


Migrating a network to IPv6 is a time-consuming and resource-intensive process. Every device will require a new address, which must be unique. Not everything on the network must be tested and validated in an IPv6 lab setup.

IT departments must also determine whether and how to support incompatible devices and apps. IPv6 addresses are more difficult to remember and more intricate than IPv4 addresses.

Teams must first learn how to create and troubleshoot IPv6 networks before they can begin using the protocol. To keep cyberattacks (including IPv6 DDoS attacks) under control, teams must consider effective network segmentation and strategies to block specific traffic.

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