How enterprises can migrate from IPv4 to IPv6

The case for IPv4

IPv4 isn't the most modern type of IP address format, but it remains the most commonly used format among organizations. Several reasons exist for why an organization might prefer to stick with IPv4 rather than transition to IPv6. Those reasons include the following:

• Network address translation (NAT) helps the IPv4 address shortage problem. IPv4 allocates private address space, so businesses can use these addresses internally and only perform NAT at the network edge. Security devices at the edge have also long supported NAT. IPv6 advocates have touted an address shortage problem, but NAT has largely eliminated the issue.
• Legacy equipment might not be IPv6-compatible. Although IPv6 has been around for years, many network devices and endpoints can function only on IPv4.
• Network admins are more comfortable with IPv4. Most network engineers focus their attention on building and managing networks that operate with IPv4. This is slowly changing, but a transition to IPv6 could require additional training in some cases.
• The organization can't justify ROI of an IPv6 transition. Unless businesses require improved network hardware performance efficiency, complex quality of service (QoS) policies or tighter security within the network, it might be a challenge to justify the cost to transition to IPv6.

The case for IPv6

Because IPv4 works for many organizations, opinions on whether to migrate from IPv4 to IPv6 vary widely. Proponents of IPv6 tout that the new protocol standard provides several benefits, including the following:

• IPv6 improves routing efficiency. Network teams that are responsible for handling large traffic flows might find themselves in a situation where the processing power of their existing routers and Layer 3 switch hardware can't keep up. IPv6 lessens processing overhead on networking gear, which eliminates potential bottlenecks.
• Headers enhance QoS. IPv6 headers provide additional payload information compared with IPv4. This enables greater classification granularity for organizations that require it.
• IPv6 eliminates NAT. Because IPv6 is large enough to handle up to approximately 340 trillion publicly addressable IP addresses, businesses can use these addresses to configure their networks without the need for NAT at the network edge.
• The protocol includes built-in encryption. IPv6, unlike IPv4, comes with IPsec encryption baked in to the protocol.

How to migrate to IPv6 from IPv4 networks

Organizations that decide to take advantage of IPv6 benefits can consider three common methods to make the transition. Network teams can use these steps without a complete network hardware refresh, which typically creates compatibility issues or requires significant network downtime.

Below are three ways to transition from IPv4 to IPv6:

1. Create a dual-stack network.
2. Use IPv6 tunneling.
3. Use NAT Protocol Translation (NAT-PT).

Create a dual-stack network

Most modern enterprise network equipment can operate in a dual-stack mode, which means the network can communicate with some network components and endpoints using IPv6 and with others using IPv4. Because the majority of internet-connected devices communicate only with IPv4, it's essential for organizations to maintain both protocols.

Use IPv6 tunneling

Organizations can use IPv6 tunneling to transport IPv6 packets across an encrypted tunnel. IPv6 tunneling helps address the issue of connecting network devices that lack IPv6 support. Organizations can also use IPv6 tunneling to migrate to IPv6, while they gradually replace aging IPv4-only network equipment.

Use NAT Protocol Translation

NAT-PT is a service that converts IPv4 addresses into IPv6, and vice versa. NAT-PT operates similarly to how standard NAT translates non-internet routable IPv4 addresses to one or more publicly addressable IPv4 addresses. In situations where both protocols must coexist, setting up NAT-PT gateways can provide a smooth transition as aging hardware and endpoints refresh to IPv6-capable alternatives over time.

Create an IPv6 network from scratch with a network refresh

Organizations that prefer to avoid migrating their preexisting networks from IPv4 to IPv6 can opt to wait for the next network hardware refresh cycle and build a new network with IPv6. This removes the need to create dual stacks or tunnels and the reliance on translation methodologies within the private network, all of which negate many of the performance benefits found in the more modern protocol.