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IPv4 vs IPv6: What's the Difference? [A Details Comparison]

In internet world IP address is the communication platform, in that we should know the comparison between IPv4 vs IPv6 Address.

29 Mar, 22 by Susith Nonis 17 min Read

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Earlier, the internet used IPv4 but later moved to IPv6. Do many people wonder why there was the need to move to IPv6 and its significance? Basically, for those who do not know what IPv4 and IPv6 are, these are the internet protocols providing addresses for systems. But, there was a gradual transition from IPv4 to IPv6. The difference between the two is huge. Due to the exhaustion of the IPv4 addresses, it was required to move to a new number for better access across the internet.

But, before you start transitioning your business from IPv4 to IPv6, you must understand the nature of both internet protocols. In this article, we have mentioned how both are different, their features, why there was a need for this transition, when it is the right time to do this transition, the benefits of IPv6 over IPv4, challenges while transitioning, and other necessary details.

Before moving to the differences, we must look at what IPv4 and IPv6 are?

IPv4 determines the Internet Protocol version 4, with four sets of numbers. Where each number can range from 0 to 255, forming different combinations. For example- is an IPv4 format IP address in the TCP/IP model. IPv4 uses a 32-bit IP address, providing you with the IP address - 232—or 4,294,967,296.

IPv4 was introduced into the market in the early 1980s. We usually use an IP address to identify any system and connect it over the network. After that, DNS (domain name server) came into the picture for easily accessing the systems as remembering the IP address for various devices can be confusing. DNS came into the picture to translate the IP address into a human-readable format to eliminate this challenge. For example, an URL that you use to navigate to a website using your browser.

So whenever you place a request, navigate to “www.google.com” through your browser. The DNS will translate the URL name back into the IP address (, as shown in the above image. It allows you to navigate the internet easily compared to the IPv4 address.

Features of IPv4-

  • It provides connectionless protocol.
  • You can use IPv4 for creating a simple virtualized communication layer over different types of devices.
  • It consumes less memory to store the address and is easier to remember the address.
  • It has been widely supported by millions of devices across the globe.
  • It comes with wide support for videos libraries and conferences.

Here, IPv6 stands for the Internet protocol version 6. It was launched in the 1990s to replace the internet protocol version 4. Rather than using the 32-bit addresses, IPv6 uses the 128 bits addresses that have expanded the range of the addresses. It offers eight groups for extended address combination, where four are hexadecimal numbers separated by a colon character.

It came into the picture as the addresses under IPv4 are getting short, and there was a requirement for a new address set for specifying the devices over the internet. IPv6 allows for a theoretical 340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undecillion addresses, providing a unique IPv6 address to every device available on the internet.

An example IPv6 address looks like this- 2002:0de6:1001:4042:0110:8c2e:0370:7264. Ipv6 also overcomes several challenges faced by IPv4. Here, we will explain how IPv6 is preferable to IPv4.

Features of IPv6:

  • You will get a hierarchical addressing and routing infrastructure.
  • You will get stateful and Stateless configurations for your devices.
  • You can get along easily with its high-end support.
  • It is well-suited for neighbouring node interaction.

Ip addresses are used to provide an individual address space to every device. Each device is identified uniquely with the IP address. IP is available as an integral part of an internet protocol suite, along with the transmission control protocol, also known as TCP/IP. This suite sets the rules for addressing, transmitting, and receiving the data over networks.

One of the most commonly used IP formats is IPv4 addresses, also known as dotted quad decimal, x.x.x.x, where x ranges between 0 and 255. For example, IPv4 is a 32-bit address space limited to unique hosts of 232, which are around 4.3 billion IPv4 addresses.

In 2011, the Internet Assigned Numbers Authority announced that they were running out of IPv4 address free space. Then they thought of recovering the unused IPv4 address spaces from across the internet and then created a recovered address pool out of it. In 2014, IANA again redistributed the pool addresses, resulting in no more IPv4 addresses to be allocated.

To overcome this outrage of the address spaces, the internet gradually transitioned to IPv6 address space to provide more address space to devices. The Internet Engineering Task Force came up with the IPv6 address space in 1998, offering 128-bit addresses with a group of four hexadecimal digits (using digits 0-9 plus letters A-F) separated by colons (e.g., 2022:gb8::8a6f:762:7107).

Initially, it was considered that around 4.3 billion addresses would be sufficient to cater for the internet requirement. But it was only possible when there was less number of devices being connected to the internet, each having a unique IP address. But with time, as digitization increases, the need for mobile devices has also increased. It leads to an increased number of devices per person with different IP addresses.

Later with time, the number of devices has crossed 46 billion, leaving the IPv4 address no longer available. Also, many IPv4 addresses have been reserved for special purposes. Around 18 million IPv4 addresses were available only for private addressing. Many top-notch organizations leverage private addresses on internal networks whether they require it or not. Where another 270 million are dedicated to multicast addresses.

Also, if you want some unique IP address, it costs a fortune. Aa study estimated that, in 2020, the cost per address from a legal marketplace was $36. Even heavy black marketing was there to get the legal IPv4 address for different purposes.

Thus, IPv6 is not an option; it came out of necessity.

Running out of the IPv4 address space leads us to the newer version of IP address, IPv6. Unfortunately, this newer version does not have backward compatibility with the IPv4 version. So, you cannot use them interchangeably. Thus, allowing the organizations or individuals to either transition to the newer version or maintain a dual-stack having both IPv4 and IPv6 approaches.

Having both options takes up a lot of investment, resources, etc. Also, it will not add any additional value to your customers. But, if you are struggling to choose one of them, you can consider several benefits of IPv6 and start transitioning, if possible. They will not only provide you with a larger address space but makes your communication more efficient. Below are some benefits you will encounter with the transition from IPv4 to IPv6.

  • Extended address space

As you all know, the primary reason for coming up with the idea of IPv6 was to overcome the issue of an insufficient address pool of IPv4 addresses. All thanks to IPv6’s 128-bit structure, providing an extended address space so that every person across the globe can have several private connections. In the future, you will get a good enough space to cater to significant IP-address-intensive technology, such as the Internet of Things.

Unlike with the IPv4 address allocation, several precautions have been taken to ensure the efficient usage and allocation of IPv6 addresses. The major problem with IPv4 address availability was some companies’ “address hoarding”. They “stockpiles” the addresses never actually required by them or fully used. They did not even surrender the unused addresses. Thus, proper IPv6 address allocation is ensured by putting assignment policies.

  • Easier and efficient communication

IPv6 ensures easier communication over the internet because of the increased address space. Now each device can have its unique global address without the unnecessary requirement of complex routing methods such as translating the network address (NAT).

But considering the case of the IPv4, NAT provides a way to conserve the IPv4 addresses. It is a significant roadblock for the application development having end-to-end communications, as they often require creative workarounds for NAT traversals. With IPv6, this roadblock has been eliminated, thus leading to faster development times, easy communication, and conserved resources.

  • Autoconfiguration

This is one of the significant differences between the Ipv4 and IPv6. in the case of Ipv6, you will get a stateless address autoconfiguration. But, with IPv4, you will require a DHCP server for assigning the address to a specific device on the internet.

With IPv6, the router will provide the required network ID to all the connected devices to generate a specific host ID (the last 64 bits), resulting in a complete IPv6 address. The device sends a “router solicitation” (RS) request asking for the network address. Then, the device will get the response from the “router advertisement” (RA).

Does that eliminate the requirement of a DHCP server? Not really. Because if you have a dual-stack of IPv4 and IPv6 network, you need to configure a DHCP server for managing IPv4 address space. But even if you the dual-stack but only IPv6, you will require the server to provide the other DHCP options to your device. In some cases, you need to set up a “stateful” configuration similar to the IPv4 for more controlled IP address management.

  • Increased mobility

Due to the increased limitations of IPv4 led to the forced implementation of a special IP protocol only suitable for mobile devices known as Mobile IP (MIP) that uses the concept of triangular routing. As the address pool of the IPv4 space is getting short, it was almost impossible to allow mobile devices to maintain their IP addresses while roaming. It prevents mobile devices from being traced across locations. So, the mobile device is assigned a new IP address whenever the device moves to a new network, routing all the traffic through its home network. It has been updated to the new address, resulting in a lot of unnecessary traffic.

Unlike the mobile IPv4, the process in IPv6 is optimized as it eliminates the need for unnecessary triangular routing and uses direct routing. In this case, whenever the device is roaming, they use the home network to advertise its new IP address and make a direct connection. In this way, there is no burden on the home network to handle all the traffic.

  • Multicasting

Multicasting refers to sending a message to several destinations that want to receive those messages. You can send a multicast message using IPv4, but it is optional. But, it creates unnecessary overhead by broadcasting a message to everyone without their consent. Thus, to ensure efficiency, IPv6 does not support multicasting at all.

IPv4 and IPv6 are both addresses that provide different address spaces to the devices connected to a network. They might have the same purpose, but their work is different, as they have different features and benefits to offer. We have mentioned some of the quick differences based on some factors.




Addressing Method

Specifies a numeric address with binary bits separated by a dot (.)

Specifies an alphanumeric address with binary bits separated by a colon (:) along with hexadecimal.

Address Types

Can be used for Unicast, broadcast, and multicast.

Can be used for Unicast, multicast, and anycast.

Address Mask

for the designated network

Not used.

Header Fields

12 header fields

8 header fields

Length of Header Fields

20 length

40 length


Yes, it has.

No checksum fields.

Number of Classes

The class ranges from A to E.

An unlimited number of IP addresses.


IP addresses and routes must be assigned.

Configuration is optional


Supports VLSM

Do not Support VLSM


Done by sending and forwarding routes.

Done by the sender.

Routing Information Protocol (RIP)

supported by the routed daemon.

does not support due to it uses static routes.

Network Configuration (NC)

Manual or with DHCP.



System management protocol

SNMP does not support IPv6.

Mobility & Interoperability

Due to constrained network topologies, it has restricted mobility and interoperability capabilities.

IPv6 provides embedded interoperability and mobility capabilities.

Despite several benefits of transitioning to IPv6 address space, you might face various challenges. Thus, you must consider every aspect while starting the transition proves to be beneficial for your business. Below are some challenges being met during the transition. Consider them before you proceed.

  • Proper planning consumes a lot of time.

IPv6 is very different from IPv4, and you must not consider it a successor of IPv4. If you are thinking of transitioning your network to IPv6, it requires a lot of workarounds.

Transitioning to IPv6 requires more resources. Every company willing to make this transition must ensure that they have a proper plan for this transition, as there are high chances of failed transition.

The IT team tracks each device on their radar to provide a unique IP address. Tracking each device is not an easy task and requires manual and automated involvement in this process.

  • Compatibility issues.

You must know that each device does not show compatibility with IPv6 address space. Most application software and networking solutions do not support IPv6. To eliminate the chances of failure, you must conduct a rigorous testing process to validate everything on the network to ensure that the specific application can work efficiently after being migrated to the new protocol. IT teams must consider the facts, such as how to support devices and applications if they are not compatible with IPv6.

Many companies use dual-stack implementations to overcome this compatibility issue during the transition, where they handle both IPv4 and IPv6 simultaneously. But, managing both versions can come with the challenge of security, as you might not be able to manage how systems choose which connection type to use.

  • Different format

Remembering IPv4 addresses is complex, but it is harder to remember IPv6 because it consists of numeric and hexadecimal combinations. This might cause a much higher error while entering the IPv6 addresses manually. It is better to automate the process of entering the IPv6 address while using or connecting in crucial cases.

  • Requires skilled team for handling network.

Before the transition, all your network team, including the network admin, security analyst, and others, must understand the significant differences between IPv4 and IPv6. They differ in working, where Ipv6 is more crucial, and other factors need to be considered. Also, the IT team must know how to tackle and troubleshoot IPv6 network-related issues. So make sure you have sufficient resources and trained staff to handle this transition.

  • Security issues.

As IPv6 ensures more security than IPv4, you must still check for security vulnerabilities. Without testing, you must not start with the transition. You can follow several best practices to ensure complete security by disabling self-generating IP addresses and allowing lists to check permitted IPv6 addresses for authorized access. Teams must ensure proper network segmentation and block specific traffic to stop cyber attacks. You can even leverage the stateful DHCPv6 for better activity tracking, traceability, and visibility for more security.

  • Headers

As you are very much familar with this article after reading the difference between IPv4 and IPv6 address; also the comparison between IPV4 vs IPv6. Each device is uniquely identified by its IP address, and it is required to make connections to other devices on the network. There are two versions of the internet protocol- IPv4 and IPv6. Today, most devices have been assigned to IPv4 address space. But, as the IPv4 address space ran out, we were left with no other option other than migration to IPv6. Thus, it is necessary to develop a new address space to cater to more devices on the internet, that is, IPv6 with 128-bit address.

It is considered that IPv6 address space is sufficient for many more years. IPv6 overcomes several issues of Pv4 protocol, including security. But, transitioning to IPv6 is not as easy as it seems to everyone and takes time and detailed network knowledge. There could be several challenges that might occur. So prepare yourself and back up with the right resources before you make the transition.


Susith Nonis

I'm fascinated by the IT world and how the 1's and 0's work. While I veture into the world of Technology I try to share what I know in the simplest way possible. Not a fan of coffee, a sweet addict and a self accredited 'master chef'.