IPv4 vs IPv6: The Future Of Internet Protocols

Every internet user these days must have come across the terms IPv4 and IPv6. You might have heard people say that IPv6 is better than IPv4 and it is the future. But what exactly do the terms IPv4 and IPv6 stand for, and what is it that makes the latter one superior? If you’re baffled by the same questions, well then read on, as we discuss IPv4 vs IPv6, and take a better look at the world of Internet Protocols. But first, let us discuss what are Internet Protocols.

What is IP?

The Internet Protocol or IP is the main communications protocol in the field of Internet protocol suite for relaying datagrams across network boundaries. The Internet Protocol has a routing function that enables inter-networking between various devices across the globe, and effectively, establishes the network that we call the internet. The IP is responsible for addressing hosts, encapsulating data into datagrams, and routing datagrams from a source host to a destination host across one or more IP networks. In Lehman terms, IP contains the set of rules and guidelines that need to be followed while transmitting any data over any network spectrum.

IPv4 vs IPv6: What Do They Mean?

Internet Protocol Version 4 (IPv4) is the fourth-version of the Internet Protocol (IP). It was initially deployed for production in the ARPANET in 1983 and has since then grown to route most of the Internet traffic today. IPv4 is a connectionless protocol which is implemented on networks that make use of packet switching. It operates on the best effort delivery model, meaning that they obtain unspecified variable bit rate and delivery time, depending on the current traffic load. It does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery.

IPv4 Header
IPv4 Header Format

Internet Protocol Version 6 (IPv6) is the most recent version of Internet Protocol and the incremental update to IPv4. Essentially, IPv6 is an Internet Layer protocol for packet-switched internetworking and provides end-to-end datagram transmission across multiple IP networks, closely adhering to the design principles developed in the previous version of the protocol. IPv6 was first formally described in the Internet standard document RFC 2460, published in December 1998, but has started coming into existence on devices since late 2006.

IPv6 Header
IPv6 Header Format

IPv4 vs IPv6: Detailed Differences

Address32 bits (4 bytes)
128 bits (16 bytes)
Example12:34:56:781234:5678:9abc:def0: 1234:5678:9abc:def0
Packet size576 bytes required, fragmentation optional1280 bytes required without fragmentation
Packet fragmentationRouters and sending hostsSending hosts only
Packet headerDoes not identify packet flow for QoS handling
Includes a checksum
Includes options
up to 40 bytes
Contains Flow Label field that specifies packet flow for QoS handling
Does not include a checksum
Extension headers used for optional data
DNS recordsAddress (A) records,
maps host names
Pointer (PTR) records,
Address (AAAA) records,
maps host names
Pointer (PTR) records,
IP6.ARPA DNS domain
Address configuration Manual or via DHCPStateless address autoconfiguration (SLAAC) using Internet Control Message Protocol version 6 (ICMPv6) or DHCPv6
IP to MAC resolutionbroadcast ARPMulticast Neighbor Solicitation
Local subnet group managementInternet Group Management Protocol (IGMP)Multicast Listener Discovery (MLD)
IPSecoptional, externalrequired

Why The Need For IPv6?

IPv4 uses just 32 bits for its Internet addresses. What this essentially means is that IPv4 can support up to 2^32 IP addresses in total, which accounts to 4,294,967,296 (4.29 billion). While this does seem to be a big number, the estimated number of devices that connect to the internet exceed 20 billion, and the number seems to be growing day by day. As such, the IP address for any device needs to be specific and unique, and with the growing number of users, we are running out of IPv4 addresses.

The IPv6, on the other hand, makes use of 128-bit internet addresses. This means that the protocol can support up to 2^128 IP addresses in total, which roughly comes out to be 340,282,366,920,938,000,000,000,000,000,000,000,000 (Three hundred forty undecillion, two hundred eighty-two decillion, three hundred sixty-six nonillion, nine hundred twenty octillion, nine hundred thirty-eight septillions) (yes, that’s right!). Essentially, the IPv6 standard is more than enough to keep the Internet operational for a very, very long time.

Benefits of IPv6

The IPv6, along with increasing the number of addresses available, does come along with furthermore added benefits. With the help of IPv6, the need for Network Address Translation (NAT) has been eradicated, which was previously used to conserve global address space allocations due to the lack of IPv4 addresses. Additionally, the IPv6 also removes the possibility of private address collisions, along with better multicast routing.

IPv6 Anatomy

As compared to the IPv4 standards, IPv6 has a simpler header format, which allows for simpler and more efficient routing. It also brings about an increase in the Quality of Service (QoS), also referred to as “flow labeling”. Not to forget, the IPv6 has its own built-in authentication and privacy support and has flexible options with support for extensions. Overall, the IPv6 provides easier administration as well, bidding farewell to Dynamic Host Configuration Protocol (DHCP).

IPv4 to IPv6: The Switch

The depletion of IPv4 had been predicted years ago. In 1993, Classless Inter-Domain Routing (CIDR) was introduced, which was later replaced with the extensive use of Network Address Translation (NAT). While both the methods worked, they were nothing but temporary means to delay the IPv4 address exhaustion. Essentially, the switch to IPv6 is necessary, but the progress has been slow. To make the switch, software and routers require changes to support the more advanced network, which will take time and money.

IPv6 Timeline
IPv6 Timeline: Increase in the number of devices adopting the IPv6 Standards

As of 2014, IPv4 still carried more than 99% of worldwide Internet traffic. Despite a decade long development and implementation history as a Standards Track protocol, general worldwide deployment of IPv6 is increasing slowly.  As of 22 July 2017, the percentage of users reaching Google services with IPv6 reached 20.1% for the first time, growing at about 7.2% per year, although varying widely by region. While devices are adopting the IPv6 standards, the number of network providers switching to IPv6 is still quite low. In the meantime, IPv4 and IPv6 effectively run as parallel networks, though exchanging data between these protocols requires special gateways.

SEE ALSO: What is Dark Web and How to Access it?

IPv4 vs IPv6: The Inevitable Change

The lack of IPv4 addresses is here, but thankfully, we have the IPv6. With 2^32 addresses (I am not going to quote the exact number again), the IPv6 standard should easily stand the test of time. All the latest devices come with IPv6 as their standard, and even if you haven’t noticed it, chances are that you’ve already made the switch to IPv6. The switch to IPv6 is necessary and inevitable, one that you are bound to make soon. Or, to be honest, considering that the devices around you as well as your ISP have already switched to it, you too will make the switch.

So that’s all there is to the discussion of IPv4 vs IPv6. Tell us your thoughts on the next big thing in the world of Internet Protocol in the comments section below.

comment Comments 2
  • Abraham Y. Chen says:

    The following may sound like out-of-the-blue. To expedite the discussion, however, allow me to state that it has been in reviews at the highest levels of responsible organizations without getting a shot at yet. So, please enjoy the information.

    The IPv4 address shortage issues have been resolved. We came upon a scheme that can expand each public IPv4 address by 256M (Million) fold without affecting the current Internet. A proposal called EzIP (phonetic for Easy IPv4) has been submitted to IETF:

    Essentially, among other benefits, EzIP can establish a sub-Internet capable of serving an area with up to 256M IoTs from just one IPv4 address. This is bigger than the largest city (Tokyo metro) and 75% of the countries. This can realize the CIR (Country-based Internet Registry) model proposed by ITU a few years ago stealthily even without setting up a CIR organization. If a government is not interested in this resources, private enterprises can make use of it to provide “local” Internet service in parallel to the current “global” Internet services, very much like the Independent telephone companies in the PSTN industry.

    The current Internet then becomes the backbone / infrastructure / skeleton for interconnecting these sub-Internets, yet only for carrying inter sub-Internet traffic, very similar as the electric grid supporting islands of renewable energy generated by individual homes and businesses. Consequently, there will be a lot of spare IPv4 addresses for quite sometime to come.

    Then, much of the efforts in deploying IPv6 are no longer needed.

    Thoughts and comments will be much appreciated.

    Abe (2018-09-08 18:03)

  • Ronak says:


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