There are no more new IPv4 addresses that can be assigned in North America, as nonprofit group American Registry for Internet Numbers (ARIN) said that it has given out the last IPv4 addresses in its free pool.

The announcement is an expected one, however, as ARIN has been issuing warnings for years that IPv4 addresses were running out. Earlier in May, ARIN said that IPv4 addresses will likely run out before this year's summer season ends.

"When we designed the Internet 40 years ago, we did some calculations and estimated that 4.3 billion terminations ought to be enough for an experiment. Well, the experiment escaped the lab," said ARIN Chairman Vint Cerf.

IP addresses are the numerical identifiers given to the hardware of computers, ranging from personal desktop computers to enterprise servers.

The IPv4 protocol, which was launched back in 1981, can only accommodate a maximum of 4.3 billion unique addresses. Thankfully, a newer protocol, namely IPv6, is just waiting to be adopted by carriers and enterprises.

IPv6, which was launched almost two decades after the IPv4 back in 1999, will be able to support 340 undecillion addresses, which is 340 followed by 36 zeroes. According to ARIN, this would be enough to be able to serve Internet users for several generations.

Users and businesses that would still be needing IPv4 addresses could send in their requests to ARIN, but the organization will have to wait to be given some by IANA, or the Internet Assigned Numbers Authority, or by users that would be willing to return addresses that they will no longer be using.

IPv4 addresses can also be purchased on so-called transfer markets, with the addresses fetching prices of about $10 to $12 each. The exhaustion of IPv4 address for North America caused a change in ARIN's rules for transfer approval that eliminates restrictions on how often IPv4 address holders can transfer their addresses to others.

Users and organizations could be willing to purchase previously owned IPv4 addresses instead of migrating to IPv6 because the move will entail certain costs. There is also a waiting game between developers and consumers to see the other pick up IPv6 more before they focus on the new protocol.