Are you ready for IPv6?

Start planning now to avoid disruption.

Johannesburg, 20 Jun 2011
Read time 8min 20sec

The Internet is about to change in a major way. Though this change will be imperceptible to most users, businesses everywhere must begin equipping their networks now for a successful transition to IPv6.

The pool is drying up

Network communication, just like a face-to-face conversation, requires a common language for the successful transfer of information, says Wynand Moller, D-Link Country Manager.

The common language of the Internet is known as the Internet Protocol (IP). When a networked device such as a computer or smartphone connects to the Internet through an Internet service provider (ISP), a unique IP address is assigned to the device. This IP address allows the device to be uniquely identified and subsequently communicated over the Internet.

When the Internet was first built, engineers assumed that the original Internet Protocol, IPv4, with its pool of nearly 4.3 billion addresses, would be sufficient to last for quite a while. However, as addresses were incrementally delegated to end-users, it became apparent that IPv4 addressing would not be able to handle the immense growth of the Internet forever. By the year 1990, it was estimated that 536 million addresses, one-eighth of those available for IPv4, had already been claimed. In recent years, the use of IPv4 addresses has risen to nearly 4 billion. Most of the Internet registries that assign IP addresses are expected to run out of IPv4 address space in 2011.

IPv6, the successor to IPv4, will provide over 4 billion times more address space than IPv4. Unlike IPv4, which creates IP addresses using 32 bits of information, IPv6 uses 128 bits, effectively increasing the number of available addresses to approximately 340 trillion, trillion, trillion (3.4 x 1 038) addresses, compared to IPv4's approximately 4.3 billion (2 128). The impending exhaustion of IPv4 addresses will soon drive the migration to IPv6 on a global scale. IPv4 and IPv6 will coexist in the interim for a smooth transition. Most modern operating systems such as Windows 7, Mac OS X, and Linux now support IPv6. Mobile devices powered by operating systems such as iOS 4.1+, Windows Mobile, and Android 2.2 also already include IPv6 support.

Gradual, essential transition

Although the transition to IPv6 will be imperceptible to most users, businesses have a cause for concern, especially if their daily operations depend on the Internet. Wynand Moller mentions that networks using equipment lacking IPv6 support may experience complications when communicating with users operating IPv6 devices. Therefore, network administrators must make sure their current networks are IPv6-capable as soon as possible.

Fortunately, the transition to IPv6 will not happen overnight. A gradual process will often require that networks support both protocols simultaneously. This can be tricky, since IPv6 and IPv4 cross over different topologies and necessitate logical techniques for co-existence during the transition. Two popular logical techniques for co-existence are “dual stack” and “tunnelling”.

“Dual stack implies providing complete implementations of both versions of the Internet Protocol (IPv4 and IPv6), and configured tunnelling provides a means to carry IPv6 packets over unmodified IPv4 routing infrastructures.” (RFC 4213)

As one would expect, the implementation of both protocols side-by-side is a sure way to guarantee compatibility. Dual stack runs IPv4 and IPv6 in parallel, allowing users to reach IPv4 and IPv6 content simultaneously. Dual stack does not require any tunnelling mechanisms on internal networks. Both IPv4 and IPv6 can be run independently of each other until IPv4 is no longer needed.

Tunnelling, sometimes referred to as encapsulation, is the technique of putting IPv6 packets within IPv4 packets so they can be carried across IPv4 routing infrastructures. Simply put, tunnelling is the routing of IPv6 information or packets over IPv4 topologies. Tunnelling is somewhat less secure than dual stack because encapsulated information may not always be readily inspected by firewalls. This potential security risk makes tunnelling only a temporary workaround until IPv6 can be fully adopted.

Advantages of IPv6

During the period of IPv4/IPv6 co-existence, new networks around the globe will continue to spring up. The devices connected to these networks, will be assigned IPv6 addresses by default, thus creating a greater compatibility gap between IPv4 and IPv6 over time.

This will drive the need for IPv6 migration and eventually create a groundswell for adoption of the new protocol with plausible financial incentives and benefits from governments and service providers. Over time, obsolete IPv4 addresses will be in short supply, and therefore more expensive to attain from ISPs. Conversely, IPv6 addresses will be less expensive due to their abundance. Existing home users and small businesses will eventually be assigned IPv6 addresses exclusively due to the scarcity of IPv4 addresses.

IPv6 may save money for those businesses that make IPv6 a priority, but the additional benefits of upgrading cannot be overlooked either.

Some of the notable improvements include the following:

IPv6 provides the option for network auto configuration, meaning any IPv6 device can be connected to the network, powered on, and it will successfully generate an IPv6 address itself without the need to enter a static entry in a DHCP server. If the device is connected to an IPv6 router, it can generate a local address and a globally routable address, offering immediate access to the Internet.

Built-in security
Another major step forward for IPv6 is its built-in security and intrinsic payload encryption. Unlike IPv4, IPv6 packets ensure end-to-end security since data contained within them cannot be readily decoded by middlemen.

Improved quality of service (QOS) support
The adoption of IPv6 also carries notable QOS improvements. Applications that require low latency, such as VOIP, and streaming multimedia can mark their network packets with the appropriate priority level for transfer across a wide area network (WAN) without delay.

Routing improvements
Internet routing tables have become extremely complex across the Internet in its present state. The structured network address allocation scheme used for IPv6 helps to reduce the current load on wide area network infrastructure. IPv6 additionally includes a more sensible scheme to support multicast routing.

Simplified packet header
The new simplified and standardised packet header used in IPv6 also improves routing. IPv6 uses a fixed-length header comprising 40 bytes. Only eight bytes of that is general information. This configuration allows information to be routed much faster. IPv6 also eliminates fragmentation fields from the packet header for greater efficiency. Extension headers can still be used, but only when needed.

Improved mobility
IPv6 provides better mobility for users moving from one subnet to another. A mobile network connection will be maintained transparently since each device, such as a smartphone or tablet, is identified by its home address. If a device connects through a foreign network, its location information will be relayed to a home agent. The home agent intercepts the packets intended for the device and then tunnels them to its location. In short, roaming across networks has the potential to be seamless for users operating on IPv6.

World IPv6 Day
Industry players are working together in support of the new protocol on an accelerated timeline beginning with World IPv6 Day on 8 June 2011. This is the day designated for a global-scale test flight of IPv6 sponsored by the Internet Society (ISOC). Major Web-based companies and other industry players will come together to enable IPv6 on their sites for 24 hours. More information about World IPv6 Day is available at:

D-Link IPv6 readiness
As a designer and implementer of IPv6 since 2005, D-Link will participate in World IPv6 Day to test IPv6, discover and address any potential issues, and raise awareness of the need for IPv6 readiness. The goal is to motivate organisations across the industry - ISPs, hardware makers, operating system vendors and Web companies - to prepare their services for IPv6 and ensure a successful transition.

All new D-Link routers, switches and access points are IPv6-ready. D-Link networking solutions support dual stack and tunnelling techniques for a smooth transition. D-Link managed switches provide a complete solution for the transition from IPv4 to IPv6. Select IP surveillance models currently support IPv6, with all newly released and future models slated to include support for IPv6. A firmware update will soon provide D-Link NAS devices with IPv6 capabilities.

Be prepared

If the transition to IPv6 seems like something that will impact your business, here are some actions you can take:

1. Be proactive. Although the impact may not be immediate, and the transition may seem gradual or far away, acting now could spare you major headaches down the road.
2. Prepare for the change. Learn and understand the steps involved in IPv6 migration. Make sure your IT staff is up to speed.
3. Plan ahead. Develop a comprehensive deployment plan now to ensure you stay connected in 2011 and beyond.
4. Ensure that all newly purchased networking equipment is IPv6-compatible.
5. Upgrade one step at a time, and ensure that everything is operating correctly. Check that your current network can handle both IPv4 and IPv6 traffic.

6. Let D-Link help you. For more information about D-Link IPv6 solutions, please visit: or contact your nearest D-Link representative.

Editorial contacts
D-Link Wynand Moller (+27) 012 661 2025
See also