The Internet was initially thought to be made to provide end-to-end connectivity the much-needed support. This means that each device or host on the internet should be able to communicate with other devices directly (the way a peer-to-peer model works). At the time when the internet was conceived, IPv4 was chosen as the sole network protocol (IPv6 was not even thought of). That day was January 1, 1983, and at that time, 4.3 billion IPv4 addresses seemed to be a lot numerically (2^32bits).
But with the massive growth of the internet (thanks to computers and the world wide web), it became evident that IPv4 addresses will become extinct. Numerous mechanisms were added to slow down the exhaustion of IPv4 addresses. Even top-notch cheap dedicated server hosting companies used IPv4. Among them were:
- CIDR (Classless Inter-Domain Routing).
- Private IP addresses.
- NAT (Network Address Translation).
A new version of the Internet Protocol was proposed at the same time. It was made a universal standard. Hence it would become the permanent solution to IP addresses. That protocol is Interner Protocol version 6 (IPv6).
This technology uses 128-bit addresses. It theoretically can provide more IP addresses than IPv4. Meaning, it would provide more addresses than the approximation of the amount of sand grains present in the world.
Any barriers or concerns regarding Migration to IPv6
Experts who forecasted the IPv4 address space exhaustion were correct. There are five regional internet registries (RIRs) tasked with the allocation of public IPv4 addresses. Currently, only one RIR (AFRINIC) is using IPv4 addresses for allocation. They are now known to be depleted.
Despite rumors of IPv4 addresses being exhausted, unallocated blocks are still available. Numerous internet service providers (ISPs) around the world have them. Numerous RIRs have also created transfer policies that move IP addresses between various entities. Even the best dedicated server is facing IPv4 address exhaustion.
Experts today are somehow wondering how does IPv6 make up less than 20% of the internet traffic if IPv4 addresses have been exhausted? Let us have a look at some of the reasons mentioned here:
The effectiveness of Workarounds
CIDR, making private IP addresses and NAT in various forms did work to reduce the impact of exhaustion of IPv4 addresses. This might be okay for existing companies as new companies can find it hard to acquire a public IPv4 (due to the depletion).
Also, numerous companies (Meta especially) are headed for IPv6. This indicates numerous services will be reachable via IPv6. Those who are using IPv4 may not be able to access them after some time. In the least possible probability, they might end up receiving poor-quality services.
Lack of knowledge of IPv6
Regarding IPv6 a general lack of understanding exists. Apart from being different from IPv4, it is not backward compatible, unfortunately. It is because of this fact that a lot of companies aren’t willing to take the risk. A set of training programs can work in this regard though.
The perceived implication of expenses
As IPv6 is a new version of internet protocol, a lot of organizations are fearful of the expense implications. However, IPv6 isn’t that new, and a draft standard was released back in 1998. This indicates that most devices are already supporting IPv6 and the perceived cost of moving to IPv6 isn’t as expensive as earlier thought.
The Migration from IPv4 to IPv6 – the steps involved
It is now an excellent time to examine the process of migration from IPv4 to IPv6 in brief detail:
The migration project’s plan, scope, and objectives
Moving from IPv4 to IPv6 is indeed a big deal. Like most projects, companies need to have a plan, a defined scope, and the project objectives identified. Looking at the goals of migrating to IPv6, here are some scenarios to have a look at:
- Obtaining an IPv6 address block so internal users on the network wanting to experiment with IPv6 can obtain services on the internet.
- Enabling IPv6 only within internal networks. It means communicating within the network using only IPv6. Yet users still access the internet based on IPv4.
- Enabling IPv6 at the network’s end so external users can access relevant services.
It is wise to make a team that will manage the migration. It is not easy justifying the whole process. This is why support from top executives is needed.
The network readiness assessment
The next step pertains to conducting a complete audit of the network. Both network hardware and software will be checked. This helps determine three major things:
- Which components are ready for IPv6?
- What kind of network components need core upgrades to support IPv6?
- Which network components need replacement to support migration to IPv6?
It is at this point the cost implications of migrating to IPv6 should become clear now. It should be kept in mind that the expenses should not be restricted to just software and devices. Operational expenses, training, and others need to be counted.
The addressing plan – making the addresses
The immense size of IPv6 addresses is overwhelming. As such, it is hence recommended that companies have a plan for allocating their respective IPv6 address block within their systems. This depends on the size of the company and of the Internet Service Provider (ISP) willing to provide the address block. Each ISP provides a different block.
Assuming a company received a /48 block from their respective ISP. If they wish to keep with the recommendation regarding the last 64 digitals of an IPv6, it means they have 16 bits to create subnets. They can be divided into different parts representing different legions, locations, types of devices, and vice versa.
IPv6 addresses are not rigid like their IPv4 counterparts. Yet companies should plan the former in a way that makes aggregating on them easily. This helps reduce the size of the routing table. It even helps reduce the impact on the router’s performance.
Depending on the project’s scope, companies may also need to find out how the end devices will obtain IP addresses. Here are some methods they can use in this regard:
- Manual configuration (suitable for new servers).
- Stateless Address Automatic Configuration (SLAAC).
- Dynamic Host Configuration Protocol version 6.0 (DHCPv6).
Completing the transition from IPv4 to IPv6
A lot of companies still rely on IPv4. Making the switch to IPv6 does not happen in a day. Hence there needs to be a way to make a gradual transition from IPv4 to IPv6. This indicates that in most cases, IPv4 and IPv6 exist together and will probably do so for a long time.
Transition methods
Here are some techniques facilitating the transition between IPv4 and IPv6:
The Dual Stack Method
This technique helps all network devices get configured for both IPv4 and IPv6. This is the recommended approach and has numerous advantages. Yet disadvantages are also present.
For instance, the expense of running a dual-stack rises both on device capacity needed and on administrative operations. Moreover, all entities along the path need to support it. This isn’t feasible.
Tunneling Method
In this scenario, a protocol is put inside another one. For instance, a company has two IPv6 networks that need communication with each other. However, both are connected through an IPv4 network. IPv6 traffic here can be routed in a tunnel-like manner inside IPv4 packets. They are hence tunneled over the existing IPv4 network.
Here are some examples of tunneling technologies worth noting:
- Manual and automatically configured tunnels (6in4).
- Rapid deployment of IPv6 (6rd).
- Intra-Site Automatic Tunnel Addressing (ISATAP).
The Translation Method
This Translation technique involves translating one protocol to the other. This allows IPv6 hosts to communicate with IPv4 ones. Common translation mechanisms used are DNS64 and NAT64.
Conclusion
The transition of going from IPv4 to IPv6 sounds dreading to some. Yet it is now a necessity as internet connections need complexity and IPv4 addresses are being exhausted.
