The End of IPv4: What Your Company Should Know

Posted on: September 16th, 2012 by Cascadeo Corporation

On February 3, 2011, the Internet Assigned Numbers Authority (IANA) distributed the last blocks of IPv4 address space in the free pool to the Regional Internet Registries (RIRs), ARIN, RIPE, AFRINIC, APNIC, and LACNIC. This followed a global policy stating that when the IANA had only five /8-sized blocks, it would give one to each RIR. This means that after this year, no more new IPv4 addresses will be given out.

Currently, Internet service providers (ISPs) apply to one of the RIRs for IP address space, based on policies developed for their region. ISPs, in turn, assign IP address space to their customers. Organizations may also go directly to an RIR, to get provider-independent (PI) address space.

Now that the IANA has no more IPv4 address space, the RIRs will no longer receive new IP addresses directly from IANA and will run out of IPv4 addresses this year. How does this affect you? The next time you or your ISP requests additional IPv4 address space, the request will be rejected. Although opportunities to acquire IPv4 addresses from organizations that have spare allocations may exist, this will likely be both difficult and costly.

Fortunately, the IPv4 Internet will continue to function properly even when all IPv4 address space is gone. However, growing businesses will find expansion increasingly difficult, without additional address space to connect more devices and customers.

What is IPv6?

By the 1990s, IPv4 address space was clearly running out. The Internet Engineering Task Force (IETF), the primary standards body for the Internet, designed a protocol called IPv6. Compared with IPv4’s 32-bit (2^32) address space, IPv6’s enormous 128-bit (2^128) address space easily provides enough space for the foreseeable future. However, many businesses have been slow to adopt IPv6 because of the significant effort involved in doing so and the critical need that was not yet apparent.

What does this mean for your business?

IPv6 does not operate alongside IPv4, but as a completely separate protocol. Businesses that want to remain competitive must apply a mechanism to their infrastructure that allows both versions to run. Therefore, it is essential that your network devices be upgraded and configured to run dual-stack, to cope with the coming IPv6 traffic and to let your business continue to grow. Dual-stack refers to running IPv4 and IPv6 simultaneously. This allows your servers to respond simultaneously both to the old IPv4 requests and to the newer IPv6-connected devices.

Cascadeo recommends a complete audit of your network and systems infrastructure, to determine how to upgrade it to dual-stack. Once the audit is done, a comprehensive transition plan can be implemented.

It will be a very long time, if ever, before IPv4 will be completely gone from the Internet. However, any company with a presence on the Internet, but without IPv4 reserves, must migrate to IPv6 in order to grow.

World IPv6 Day

On June 8, 2011, many major Internet-based companies around the world will go IPv6 for the day. Sites like and will change their DNS so that you can reach them only via IPv6. This is a test to motivate everyone to start thinking about, and migrating to, IPv6.

Cascadeo encourages you to review the links below and consider taking part in World IPv6 Day.

We look forward to working with you on the exciting transition ahead!


World IPv6 Day

IANA Free Pool Exhaustion

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