What’s IPv6?

What is the IPv6 protocol

The Internet Protocol version 6 or IPv6 is a version of the Internet Protocol (IP). The Internet Protocol allows to transfer data through a network to IP addresses (version 4 or version 6), which identify the different devices that are connected to the Internet, allowing communications among them.

The Internet Protocol version 6 presents significant improvements in terms of efficiency, performance and security. From the beginning, Stackscale has been a leader in the implementation of IPv6 on its network, offering the possibility to deploy services to all the customers on this new protocol, which should end up replacing IPv4.

The transition to IPv6 is necessary for technological advances, specially in light of the exponential growth of connected devices derived from the development of the Internet of Things (IoT).

How is an IPv6 address?

One of the biggest changes of IPv6 in respect to IPv4 is the length of the network addresses. IPv6 addresses have 128 bits, it is to say, 32 hexadecimal digits; an important improvement against the 32 bits of IPv4 addresses. Moreover, IPv6 addresses can be composed by two logical parts: a 64-bit prefix and a 64-bit interface identifier.

IPv6 hexadecimal address Stackscale

The interface identifier is almost always generated automatically based on the MAC address of the interface to which the address is assigned. This is one of the advantages of implementing it on the IoT, providing a unique IP address to every connected device.

Advantages of the Internet Protocol version 6

These are some of the advantages of this new protocol of IP addresses.

  • A nearly unlimited number of unique IP addresses. This new protocol allows that every device connected to the Internet has its own IP address. An advantage that is slowly becoming a requirement due to the constant development of the Internet of Things.
  • Native support for mobile devices. IP version 6 supports the mobile IPv6 protocol, MIPv6, which allows mobile devices to change from one network to another and to receive itinerary notifications regardless of its physical location.
  • Autoconfiguration. The new protocol includes better methods to do automatic configurations, bringing a significant improvement in comparison with the classic DHCP used in IPv4.
  • Improved security. The IPv6 protocol can be improved with IPsec (Internet Protocol Security) in order to manage the encryption and authentication between hosts. This new protocol provides a strong end-to-end security framework for data transfer.
  • Improved efficiency. Package management is much more efficient.

IPv4 vs. IPv6

The Internet Protocol version 4 or IPv4 is the first version of the Internet Protocol, deployed for production in ARPANET in 1983; currently, the most widespread IP version globally. Nevertheless, since 2010 the end of IPv4 addresses have become a source of concern; that is why the IPv6 was defined in the RFC 2460 with the aim of replacing the “exhausted” IPv4, RFC 791.

IPv4 vs IPv6 structure Stackscale

The design of IPv6 was in charge of Steve Deering of Xerox PARC and Craig Mudge. The goal was to increase the number of IP addresses available on the Internet. Since 2016, IPv6 is being implemented in the big majority of devices connected to the Internet.

What’s the problem with the IPv4 protocol?

The problem of the current protocol, IPv4, is the limit of IP addresses it allows — a maximum of about 4.300 million unique IP addresses. IANA’s global stock of available IPv4 addresses was depleted in 2011 and in November 2019 RIPE ran out of IP addresses. The new IPv6 standard is born not only to be able to provide a unique IP address to each device connected to the Internet, but also to improve the Internet service globally.

IPv4 allows 4.294.967.296 different host addresses; a completely insufficient number for assigning an address to each person on earth and much less to assign one to each device connected to the Internet nowadays and in the future. However, IPv6 allows 340.282.366.920.938.463.463.374.607.431.768.211.456 (2128 or 340 sextillions of addresses) — nearly 6,7 x 1017 (670 quadrillion) addresses per square millimeter of the Earth’s surface. This is, undoubtedly, one of the keys that will force the real and massive adoption of the IPv6 protocol.

Differences between IPv4 and IPv6

Although both IPv4 and IPv6 are used to identify machines connected to a network, there are many differences between both protocols. These are some of them:

  • IP address’ size
    • IPv4: 32 bits
    • IPv6: 128 bits
  • Addressing method
    • IPv4: numeric and binary bits separated by a dot (.).
    • IPv6: alphanumeric and binary bits separated by a colon (:).
  • Classes of IP addresses
    • IPv4: five different classes of IP addresses.
    • IPv6: a nearly unlimited number of IP addresses. Moreover, it includes support for ranges considered as “private”.
  • Configuration
    • IPv4: each system must be configured in order to communicate with others. The network is also configured manually or using DHCP.
    • IPv6: optional configuration depending on the functions needed and it supports autoconfiguration between IPv6 devices.
  • Interoperability
    • IPv4: network topologies are rather restricted, with limited interoperability and mobility capabilities.
    • IPv6: interoperability and mobility capabilities included in network devices.

How many IP addresses are there in an IPv4 /24 and in an IPv6 /64?

The number after the slash (/) is the size of the block assigned to an IP address. This indicates the number of IP addresses within the block. The higher the number after the slash, the lower the number of IP addresses contained in the block and vice versa.

IP addresses in an IPv4 /24

In an IPv4 /24 there are 256 IPv4 addresses. /24 means that the first 24 bits out of the 32 bits of the IPv4 address are defined by the network and the other 8 bits left are defined by the host.

The biggest block that can be assigned to an IPv4 is /8; these are the blocks assigned to regional registers such as ARIN or LACNIC. In an IPv4 /8 there are 16.777.216 IP addresses. The smallest block is /32, which corresponds to a unique IP address.

Examples of allocations in IPv4
PrefixIPv4 addressesMask
/321 (20)
/24256 (28)
/1665.536 (216)
/816.777.216 (224)

IP addresses in an IPv6 /64

In an IPv6 /64 there are 18.446.744.073.709.551.616 IPv6 addresses. /64 is the default prefix for IPv6 addresses. /64 means that the first 64 bits out of the 128 bits of the IPv6 are defined by the network and the other 64 bits left are defined by the host.

The minimum block allocated to ISPs by regional and national registers is /32.

CIDR: Classless Inter-Domain Routing

This new method for allocating IP addresses is known under the acronym “CIDR” (Classless Inter-Domain Routing), and it was introduced by the IETF (Internet Engineering Task Force) in 1993. The CIDR is a network standard for allocating IP addresses and IP routing. 

The CIDR allocation method helped slow down the fast exhaustion of IP version 4 addresses.

IPv4 pools state per zones

Gráfico del estado de los pools de IPv4 por zonas

Source: potaroo

The graphic above shows how IPv4 ranges has been exhausted at a fast rate in all zones. Even so, the popularization of the IPv6 protocol is advancing too slowly. One of the reasons is the slow adoption of the Internet Protocol version 6 by ADSL and Fiber optics providers, who should be the main responsible organizations to ensure its adoption so that all users start navigating natively with the new protocol.

Transition from IPv4 to IPv6 within Europe

Adoption rates vary significantly within Europe. While the adoption rate in some countries is close to 50% or even above — Belgium (>59%), Greece (>50%) and Finland (>42%) — other countries are far below 10% — Spain (2-3%), Italy (5-6%) and Denmark (~7%), among others. Check the world’s IPv6 adoption map for further details.

IPv6 protocol at Stackscale

Stackscale supports IPv6 since its foundation. All our customers can have an IPv6 addressing free of charge. Several million IPs of exclusive use, particularly a range /64 which is 2 raised to the power of 64, which represents 18.446.744.073.709.551.616 IPv6 addresses.

Would you like to start using IPv6 in your projects and domains?

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