IPv4 to IPv6: Making a smooth transition

During the August-2019 edition of the South African Network Operators Group (SafNog) Conference, which was held in Johannesburg South Africa, it was revealed that Africa ranks the lowest in the global adoption rate of IPv6 deployment.

Africa has recorded only a 1.8 percent IPv6 migration rate, compared to America’s 30.5 percent, Europe’s 17.6 percent, Asia’s 25 percent, and Australia’s 20 percent. South Africa was ranked highest in Africa with 0.22 percent while Nigeria was ranked at zero-point level. Sad but not shocking I would say!

Before getting into the meat of the matter, I would like to give a bit of background information on how IPv4 got to a state of exhaustion.

IPv4 Exhaustion

The talks around migrating off IPv4 internet addresses have been from the 1980s when IPv4 address depletion was known to be imminent, primarily due to insufficient capacity in its design, as it provides only about 4.29Billion addresses – over 54 percent of the world population as at 2019, implying that 45 percent of the world population will never be able to connect to the internet assuming each person has only 1 device to connect with, and this is hardly ever the case in reality. According to data from statista.com, there were 8.6 billion devices connected to the internet in 2019 and this is forecasted to reach 29.4 billion by the year 2030.


IPv6 was developed and standardized, as the next-generation Internet Protocol in 1996, its main goal was to massively increase the number of IP addresses available. It encompasses many design improvements, including the replacement of the 32-bit IPv4 address format with a 128-bit address, providing an addressing space without limitations for the foreseeable future. IPv6 addresses are denoted as eight groups of four hexadecimal numbers, each separated by colons.

The full address may sometimes be shortened, for example, 2001:8a2e:0000:0000:0000:0db8:0370:7334 becomes 2001:8a2e::db8:370:7334.

IPv4 and IPv6 are not compatible, thus data sent via an IPv4 address cannot be delivered directly to a recipient on an IPv6 address, hence, communication between systems using the different address formats would require software changes, and in some cases hardware changes, for the communication to proceed successfully from end-to-end.

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Benefits of IPv6

Sufficient IP addresses – IPv6 will create a sufficient IP address pool for use by persons, as well as machines, facilitating the Internet of Things networks. It gives approximately 340 undecillion IP addresses (2^128).

Routing Efficiency – the hierarchical structure of the IPv6 addresses reduces the size of the routing table and facilitates route aggregation across the internet.

Quick Data Flows & Bandwidth Optimization – IPv6 uses multicast in place of broadcast. With multicast, packets of data can be sent to multiple destinations faster. This helps save network bandwidth.

Faster Packet Processing – IPv6 uses a packet header with a fixed header length, which simplifies packet processing. Unlike IPv4, which uses a header checksum to detect errors in the header of the IPv4 packet, IPv6 does not consist of a header checksum. This saves time and makes packet processing extremely efficient. IPv6 addresses support the auto-configuration mode that makes for more flexibility and manageability of large networks.

Migration to IPv6

Dual-stack is a migration technique that allows network devices to configure both versions of IP on each node. Devices running in dual-stack mode can communicate with other devices running in IPv4 mode, and IPv6 mode as well as devices also running in dual-stack mode. Dual-stack makes it easy to fully transition to native IPv6, as IPv4 can be turned off when not in use, and Clients can natively access both IPv4 and IPv6 services simultaneously. It however increases operational costs in maintaining the 2 protocols and also requires the use of IPv4 resources which are scarce and expensive.

Tunneling, on the other hand, is a technique that involves encapsulating one protocol inside the other. I.e. two devices running IPv6-only services can communicate with each other if their traffic from the source router is encapsulated in an IPv4 packet and then traverses an IPv4 network. Tunneling enables IPv6/IPv4 islands to be connected over already existing IPv6-only/IPv4-only network infrastructure; it also allows for isolated and/or simplified IPv6 deployment. It is however difficult to scale once the number of tunnel endpoints to be connected increases, It also leads to fragmentation due to increased packet size which is an issue as IPv6 does not support non-source fragmentation. Tunneling also results in additional header overhead.

The third migration technique – Translation, works by converting IPv6 headers to IPv4 headers, and addresses in the IPv6 to IPv4 direction; it also updates the transport checksum but the data in the packet is unchanged. Translation, like Tunnelling, also enables IPv6/IPv4 islands to be connected over already existing IPv6-only/IPv4-only network infrastructure, it however leads to increased latency in cases where the double translation is required and also requires extra processing resources.

In conclusion, when considering what migration technique to employ in transitioning from Ipv4 to Ipv6, no one approach is best for every situation. Each network’s unique requirements will dictate the appropriate solution best suited for it.

Internet Service Providers, ISPs in Nigeria have a critical role to play in ensuring that Nigeria picks up the pace with IPv6 deployments, to enable Africa to catch up with other regions and cause her to begin to experience the immense benefits and increased quality of service that comes with IPv6 networks.

Next Steps

Train network engineers on IPv6. AFRINIC offers free training at afrinic.academy and a world-recognized certification – certi6.io, network assessment to evaluate migration readiness, budget/cost-benefit analysis to confirm project viability for the business, upgrade network components for IPv6 compatibility, plan for implementation and get additional help if needed – AFRINIC provides support for IPv6 deployments – bit.ly/6DeployEN and execute.

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