IP address assignments around the world are handled by the Regional Internet Registries (RIR). In the beginning of May, I had the pleasure to attend and be a speaker at the LACNIC (the Latin American RIR) conference in Cancun, Mexico. My talk about IPv6 and DNS was very well received and I think the audience really understood how running the DNS supporting dual stack or IPv6-only clients differs from running in a pure IPv4 environment. There were several other talks, most of them discussing IPv6 and how to handle the depletion of IPv4 addresses.
In terms of the depletion of IPv4 addresses, all RIRs have implemented a phased approach to handing out their remaining IPv4 addresses. In this phased approach it will be harder and harder to get IPv4 addresses allocated from the RIRs as they move from phase to phase. Most RIRs have decided that the first of these phases, the depletion phase, will be reached when about 16 million addresses (A network of size /8) are still available in their pool. However, LACNIC took a somewhat different approach. Instead they decided to go into a limited depletion phase when they reached 8 million (/9) free addresses and a more restrictive phase once they reached 4 million (/10) free addresses.
At the time of the event, LACNIC had around 14-15 million addresses left in their free pool. Demand for the last blocks has been very high and on May 20th, LACNIC announced that they are down to one /9. This means that LACNIC entered the more restrictive depletion phase and also triggered the RIR’s parent organization (IANA) to send some recovered addresses to each RIR (about 2 million addresses to each RIR).
The next phase for LACNIC was triggered on June 10th when they reached a /10 (about 4 million addresses). Once this phase is reached the policy restricts allocation to only 1000 addresses every 6 months per member. 1000 is not a lot of addresses – they can perhaps be used for translators when implementing IPv6 so that backwards compatibility with IPv4 still can be achieved using NAT64/DNS64 but not to any dual stack deployment.
The final phase will occur when a /11 (about 2 million addresses) are left. At that point a limited number of IPv4 addresses will only be available for new members.
We are, in other words, very close to going IPv6-only in Latin America. During the last year this region has used up a lot of IPv4 address space and is currently the region with the fewest IPv4 addresses remaining. Latin American service providers should make sure their DNS servers can receive traffic over IPv6 so that their customers can still reach them.