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====ARIN (Most of North America)====
====ARIN (Most of North America)====
[[ARIN]] will generally tighten IPv4 allocations once IANA has run out, restricting allocation to supply of three months. They can only be applied for every three months.<ref name="autogenerated1">{{cite web|url=https://www.arin.net/resources/request/ipv4_depletion.html |title=IPv4 IANA Free Pool Depletion – FAQ |publisher=Arin.net |date= |accessdate=2011-02-03}}</ref> A /10 block will be set aside for services like NAT464 for IPv6 deployments; Once the other stocks have run out, each RIR can receive at most one /24 block from this /10 block every 6 months. John Curran of ARIN expects exhaustion of these other stocks in 6 to 9 months,<ref>{{cite web|url=http://www.enterprisenetworkingplanet.com/news/article.php/3923031/Last+of+the+IPv4+Addresses+Allocated.htm |title=Last of the IPv4 Addresses Allocated |publisher=www.enterprisenetworkingplanet.com |date=2011-01-01 |accessdate=2011-02-03}}</ref> but emphasizes uncertainty. Projections give a mid 2012 dates,<ref>{{cite web|url=http://www.ipv4depletion.com/?page_id=77 |title=The IPv4 Depletion site » Tool |publisher=Ipv4depletion.com |date= |accessdate=2011-02-03}}</ref> but again, they are regarded as optimistic.
[[ARIN]] will generally tighten IPv4 allocations once IANA has run out, restricting allocation to supply of three months. They can only be applied for every three months.<ref name="autogenerated1">{{cite web|url=https://www.arin.net/resources/request/ipv4_depletion.html |title=IPv4 IANA Free Pool Depletion – FAQ |publisher=Arin.net |date= |accessdate=2011-02-03}}</ref> A /10 block will be set aside for services like [[NAT64]] for IPv6 deployments; Once the other stocks have run out, each RIR can receive at most one /24 block from this /10 block every 6 months. John Curran of ARIN expects exhaustion of these other stocks in 6 to 9 months,<ref>{{cite web|url=http://www.enterprisenetworkingplanet.com/news/article.php/3923031/Last+of+the+IPv4+Addresses+Allocated.htm |title=Last of the IPv4 Addresses Allocated |publisher=www.enterprisenetworkingplanet.com |date=2011-01-01 |accessdate=2011-02-03}}</ref> but emphasizes uncertainty. Projections give a mid 2012 dates,<ref>{{cite web|url=http://www.ipv4depletion.com/?page_id=77 |title=The IPv4 Depletion site » Tool |publisher=Ipv4depletion.com |date= |accessdate=2011-02-03}}</ref> but again, they are regarded as optimistic.


ARIN will futhermore clear the 45/8 former Interop block in April. Potentially, it could be returned to IANA at that time, depending on policy, and eligibility of ARIN for new address space at that time.<ref name="autogenerated1"/>
ARIN will futhermore clear the 45/8 former Interop block in April. Potentially, it could be returned to IANA at that time, depending on policy, and eligibility of ARIN for new address space at that time.<ref name="autogenerated1"/>

Revision as of 17:41, 3 February 2011

IPv4 address exhaustion is the term applied to the ultimate result of the decreasing supply of unallocated Internet Protocol Version 4 (IPv4) addresses available at the Internet Assigned Numbers Authority (IANA) and the regional Internet registries (RIRs) for assignment to end users and local Internet registries, such as Internet service providers. IPv4 provides for approximately 4 billion addresses, divided to 256 /8 primary allocation blocks. IANA's primary address pool was exhausted on February 3, 2011 when the last 5 blocks were allocated to the 5 RIRs.[1] Several RIRs are expected to run out of IPv4 addresses before the end of 2011;[2] once the first RIR has run out, the end-to-end routable IPv4 Internet will be officially obsolete.

The depletion of the IPv4 allocation pool has been a concern since the late 1980s, when the Internet started to experience dramatic growth. The Internet Engineering Task Force (IETF) created the Routing and Addressing Group (ROAD) in November 1991 to respond to the scalability problem caused by the classful network allocation system in place at the time.[3][4]

The anticipated shortage has been the driving factor in creating and adopting several new technologies, including classful networks in the 1980s,[citation needed] Classless Inter-Domain Routing (CIDR) methods in 1993, network address translation (NAT) and a new version of the Internet Protocol, IPv6, in 1998.[4]

The transition of the Internet to IPv6 is the only practical and readily available long-term solution to IPv4 address exhaustion. Although the predicted IPv4 address exhaustion was already approaching its final stages, most providers of Internet services and software vendors were just beginning IPv6 deployment in 2008.[5]

IP addressing

Every host on an IP network, such as a computer or networked printer, is assigned an IP address that is used to communicate with other hosts on the same network or globally. Internet Protocol version 4 provides 232 (approximately 4.3 billion) addresses. However, large blocks of IPv4 addresses are reserved for special uses and are unavailable for public allocation.

The IPv4 addressing structure provides an insufficient number of publicly routable addresses to provide a distinct address to every Internet device or service. This problem has been mitigated for some time by changes in the address allocation and routing infrastructure of the Internet. Classful networking and particularly Classless Inter-Domain Routing delayed the exhaustion of addresses substantially.

In addition, network address translation permitted large Internet service providers to allocate only one public IP address to each of their customers, by masquerading the customer network behind this address with specially configured customer-premise Internet routers.

Address depletion

While the primary reason for IPv4 address exhaustion is insufficient design capacity of the original Internet infrastructure, several additional driving factors have aggravated the shortcomings. Each of them increased the demand on the limited supply of addresses, often in ways unanticipated by the original designers of the network.

Mobile devices
As IPv4 increasingly became the de facto standard for networked digital communication, the cost of embedding substantial computing power into hand-held devices dropped. Mobile phones have become viable Internet hosts. New specifications of 4G devices require IPv6 addressing.
Always-on connections
Throughout the 1990s, the predominant mode of consumer Internet access was telephone modem dial-up. The rapid growth of the dial-up networks increased address consumption rates, although it was common that the modem pools, and as a result, the pool of assigned IP addresses, were shared amongst a larger customer base. By 2007, however, broadband Internet access had begun to exceed 50% penetration in many markets.[6] Broadband connections are always active, as the gateway devices (routers, broadband modems) are rarely turned off, so that the address uptake by Internet service providers continued at an accelerating pace.
Internet demographics
There are hundreds of millions of households in the developed world. In 1990, only a small fraction of these had Internet connectivity. Just 15 years later, almost half of them had persistent broadband connections.[7] The many new Internet users in countries such as China and India are also driving address exhaustion.
Inefficient address use
Organizations that obtained IP addresses in the 1980s were often allocated far more addresses than they actually required, because the initial allocation method was inadequate to reflect reasonable usage. For example, large companies or universities were assigned class A address blocks with over 16 million IPv4 addresses each, because the next smaller allocation unit, a class B block with 65536 addresses, was too small for their intended deployments.
Many organizations continue to utilize public IP addresses for devices not accessible outside their local network. From a global address allocation viewpoint, this is inefficient in many cases, but scenarios exist where this is preferred in the organizational network implementation strategies.
Due to inefficiencies caused by subnetting, it is difficult to use all addresses in a block. The host-density ratio, as defined in RFC 3194, is a metric for utilization of IP address blocks, that is used in allocation policies.
Virtualization
With advances in hardware performance and processor features of server systems and the advent of sophisticated hardware abstraction layers it became possible to host many instantiations of an operating system on a single computer. Each of these systems may require a public IP address.

Predictions of exhaustion dates

Exhaustion of IPv4 addresses since 1995.
IPv4 addresses allocation rate per RIR.

Estimates of the time of complete IPv4 address exhaustion varied widely in the early 2000s. In 2003, Paul Wilson (director of APNIC) stated that, based on then-current rates of deployment, the available space would last for one or two decades.[8] In September 2005, a report by Cisco Systems suggested that the pool of available addresses would deplete in as little as 4 to 5 years.[9] In the last year before exhaustion, IPv4 allocations were accelerating, resulting in exhaustion trending to earlier dates.

Notable exhaustion advisories

  • On May 21, 2007, the American Registry for Internet Numbers (ARIN), the Anglo-American RIR, advised the Internet community that due to the expected exhaustion in 2010 "migration to IPv6 numbering resources is necessary for any applications which require ongoing availability from ARIN of contiguous IP numbering resources".[10] "Applications" includes general connectivity between devices on the Internet, as some devices only have an IPv6 address allocated.
  • On June 20, 2007, the Latin American and Caribbean Internet Addresses Registry (LACNIC), advised "preparing its regional networks for IPv6" by January 1, 2011, for the exhaustion of IPv4 addresses "in three years time".[11]
  • On June 26, 2007, the Asia-Pacific Network Information Centre (APNIC), the RIR for the Pacific and Asia, endorsed a statement by the Japan Network Information Center (JPNIC) that to continue the expansion and development of the Internet a move towards an IPv6-based Internet is advised. This with an eye on the expected exhaustion around 2010 which will create a great restriction on the Internet.[12][13]
  • On October 26, 2007, the Réseaux IP Européens Network Coordination Centre (RIPE NCC), the RIR for Europe, the Middle East, and parts of Central Asia, endorsed a statement[14] by the RIPE community urging "the widespread deployment of IPv6 be made a high priority by all stakeholders".
  • On April 15, 2009, the American Registry for Internet Numbers (ARIN), the North American RIR, sent a letter to all CEO/Executives of companies who have IPv4 addresses allocated informing them that ARIN expects the IPv4 space will be depleted within the next two years.[15]
  • In May 2009, the RIPE NCC launched IPv6ActNow.org to help explain "IPv6 in terms everyone can understand and providing a variety of useful information aimed at promoting the global adoption of IPv6".
  • On August 25, 2009 ARIN announced a joint series event in the Caribbean region to push for the implementation of IPv6. ARIN reported at this time that less than 10.9% of IPv4 address space is remaining.[16]
  • Tony Hain of networking equipment manufacturer Cisco Systems predicts the exhaustion date of the unallocated IANA pool to be early in 2011 (updated monthly).[17] His predictions use the same data source as Geoff Huston's, but the trends are generated from different subsets, and account for the different distribution rules for the "last 5".[18]

Allocation of final IPv4 space

From IANA's pool to the regional Internet registries

IANA allocated the last two /8 address blocks available via the RIR request procedures to APNIC on 31 January 2011. This left only the last 5 blocks.[19][20][21]

In accord with ICANN policies, IANA proceeded to allocate one /8 to each RIR, exhausting IANA.[22] This happened at a ceremony and press conference on February 3, 2011. It is also expected that 7.5x /8 of "various" "legacy" blocks start to be used by the RIR's at this time [1]. These blocks could potentially allow some RIR's to exhaust significantly later than six months from IANA exhaustion.

From regional Internet registries

Regional Internet Registries

After IANA exhaustion, IPv4 address space requests are already only subject to some additional restrictions ARIN,[23] so allocation policy is still largely business as usual. The rapid exhaustion of address space is to continue at the RIR level.

However, at APNIC, LACNIC and RIPE, the last block distributed to each RIR will be reserved for IPv6 transition, and distributed according to special endgame set-aside policies, severely limiting regular availability of IPv4 addresses when their other remaining pools run dry. At ARIN and AFRINIC, this will happen to part of these blocks.

Upon exhaustion at any RIR, end-to-end connectivity as required by specific applications, will not be universally available over the IPv4 internet. A new internet is set up using IPv6 addresses. However, IPv6 hosts can not directly communicate with IPv4 hosts, and have to communicate using special gateway services. There are many reliability, security, configuration implications of running an exhausted and dual protocol internet.[24] The demand for IPv6 is expected to ramp up to pervasiveness over three to four years, and is not an easy transition, according to Geoff Huston of APNIC.[25]

The time remaining until the first RIR exhaustion is a short time for the entire industry to transition to IPv6. This situation is aggravated by the likelihood that until exhaustion there will be no significant consumer demand for IPv6. David Conrad, the general manager of IANA, acknowledges: "I suspect we are actually beyond a reasonable time frame where there won't be some disruption. Now it's more a question of how much."[26] Geoff Huston says the transition to IPv6 should have started much earlier, such that by the exhaustion date it would be completed, with all devices IPv6-capable, and IPv4 being phased out.[27]

Once the first RIR has run out of IPv4 addresses, new devices and services are expected to appear on the public internet which have no individual IPv4 address available to them. This will mean that computers/devices anywhere in the world (in any RIR) which want to communicate with these IPv6-only devices will directly or indirectly have to support IPv6. APNIC is expected to be the first RIR to run out of IPv4 addresses, around the middle of 2011.

APNIC (Asia Pacific)

APNIC announced on January 31 2011 that it expects to be down to the last /8 within three to six months.[28][29] Geoff Huston of APNIC, Tony Haine of Cisco systems, and Stephan Lagerholm, all long time IPv4 exhaustion predictors and observers, share this opinion.[30][31][32] As of February 2 2011, APNIC had 3.16 /8 blocks left,[33] plus 1.5 /8 blocks from the various pools, and a final /8 will be set aside for IPv6 transition when IANA distributes the last 5 free /8 blocks to the 5 RIRs. APNIC used 23.7 million IPv4 addresses in January 2011,[34] and there are 16.7 million addresses in each /8 block. Formal projections by Lagerholm and Huston currently still show a September exhaustion, but are regarded as optimistic as they can not yet fully take into account any last minute rush.[35][36] These projected dates are significantly trending to earlier times.[36]

APNIC will continue normal allocation, until it only has 1 free /8 block left. From then on, APNIC will only allocate one /22 block to each local Internet registry (LIR). There are currently only 3000 LIRs in APNIC, with 300 new LIRs added in 2010. Since there are 16384 /22 blocks in the final /8 block, APNIC expects this last /8 block to last for many years to assist deployment of IPv6.[37]

Once APNIC has exhausted, some organisations which usually allocate from APNIC but which have a presence elsewhere, could try to get address space from other RIR's. Such RIR shopping could partially alleviate the pressing need to switch to IPv6, but it also causes earlier exhaustion at those other RIR's. RIR shopping is frowned upon in many policy discussions, and many users of large address space, such as ISP's for home users, have no significant presence abroad.

RIPE (Europe)

RIPE will continue normal IPv4 allocation until it is down to the last /8 block. Thereafter RIPE will only allocate at most one /22 block to each LIR to assist in IPv6 deployment.[38]

RIPE is expected to be the second RIR to exhaust, after APNIC. Partially this is due to the use of the 188/8 block, which they have already filled up. Other RIR's got similar blocks, but left them empty while still requesting new address space from IANA [2].

In a BBC article published on January 28 2011, the managing director of RIPE said that they expected to be down to the last /8 in September 2011.[39] Projections give a mid 2012 dates,[40] but again, they are regarded as optimistic.

ARIN (Most of North America)

ARIN will generally tighten IPv4 allocations once IANA has run out, restricting allocation to supply of three months. They can only be applied for every three months.[41] A /10 block will be set aside for services like NAT64 for IPv6 deployments; Once the other stocks have run out, each RIR can receive at most one /24 block from this /10 block every 6 months. John Curran of ARIN expects exhaustion of these other stocks in 6 to 9 months,[42] but emphasizes uncertainty. Projections give a mid 2012 dates,[43] but again, they are regarded as optimistic.

ARIN will futhermore clear the 45/8 former Interop block in April. Potentially, it could be returned to IANA at that time, depending on policy, and eligibility of ARIN for new address space at that time.[41]

LACNIC (South and Central America)

LACNIC will continue normal allocations, until they are down to a final /12 block to assist in IPv6 deployment. From that block, LIRs will only be able to get a single allocation of a /24-/22 block, and only if they have not received any previous IPv4 allocation, or if they need the allocation for critical infrastructure.[44]

According to LACNIC statistics from December 31 2011, LACNIC has 4.5 /8 blocks available (including the final /8 block IANA is expected to give to each RIR). LACNIC predicts that it will run out of IP addresses sometime between June 2012 and June 2014.[45]

AfriNIC (Africa)

AfriNIC has a relatively low rate of IPv4 address usage. Since AfriNIC received a fresh /8 in November 2010,[46] and received another /8 block in the final allocation on 3 February 2011, it will probably be a relatively long time before AfriNIC runs out of IPv4 addresses.

AfriNIC has a proposed policy for the final allocations, which has not yet been approved as of February 2011. After the IANA pool has run out, the maximum allocation would be a /13 block. Once there is only a /11 unallocated block left, the maximum allocation would become a /22 block.[47]

Endgame

By 2008, policy planning for the end-game and post-exhaustion era was underway.[48]

Several proposals have been discussed to mitigate end game shortages of IPv4 addresses, such as

Reclamation of unused IPv4 space

Before and during the time when classful network design was still used as allocation model, large blocks of IP addresses were allocated to some organizations. The Internet Assigned Numbers Authority (IANA) could potentially reclaim these ranges and reissue the addresses in smaller blocks.[citation needed] ARIN, RIPE and APNIC have a transfer policy, such that addresses can get returned, with the purpose to be reassigned to a specific recipient.[49][50][51] However, it can be expensive in terms of cost and time to renumber a large network, so these organizations will likely object, with legal conflicts possible. However, even if all of these were reclaimed, it would only result in postponing the date of address exhaustion.

Similarly, IP address blocks have been allocated to entities that no longer exist or never used them. No strict accounting of IP address allocations has been undertaken, and it would take quite a bit of effort to track down which addresses really are unused, as many are only in use on intranets.[citation needed]

Some address space that was previously reserved by IANA has been added to the available pool. There have been proposals to use the class E network addresses,[52][53] but many computer and router operating systems and firmware do not allow the use of these addresses.[54][55][56][57][58] For this reason, the proposals have sought not to designate the class E space for public assignment, but instead propose to permit private use for networks that require more address space than is currently available through RFC 1918.

Several organizations have returned large blocks of IP addresses. Notably, Stanford University relinquished their Class A IP block in 2000, making 16 million IP addresses available.[59] Other organizations that have done so include the United States Department of Defense, BBN Technologies, and Interop.[60]

ISP-wide network address translation

When Internet service providers (ISPs) implement network address translation within their network, rather than at the demarcation to customer networks, they may allocate private addresses to customers and need only one global scope address for a potentially large group of customers. However, many customers must use the gateway for traffic to the Internet.[61]

This has been successfully implemented in some countries like Russia, where many broadband providers now use Carrier Grade NAT, and offer publicly routable IP address at an additional cost.[citation needed] Similarly, Research In Motion (RIM), the maker of BlackBerry devices, currently routes all Blackberry data to central network operating centers for encryption and decryption purposes; this has the side effect of reducing the number public IP addresses necessary assigned.

However, ISP-wide NAT is not scalable, and limited to the number of ports available (approximately 65000) in the Transport Layer protocols. In addition, network address translation is not suitable for all applications.

Markets in IP addresses

The creation of markets to buy and sell IPv4 addresses has been proposed many times as an efficient means of allocation. The primary benefit of an address market would be that IPv4 addresses would continue to be available. These schemes have major drawbacks that have prevented their implementation:[62]

  • The creation of a market in IPv4 addresses would only delay the practical exhaustion of the IPv4 address space for a relatively short time, since the public Internet is still growing. This implies that absolute exhaustion of the IPv4 space would follow within at most a couple of years after the exhaustion of addresses for new allocations.
  • The concept of legal "ownership" of IP addresses as property is explicitly denied by ARIN and RIPE policy documents and by the ARIN Registration Services Agreement. It is not even clear in which country's legal system the lawsuits would be resolved.
  • The administration of such a scheme is outside the experience of the current regional address registries.
  • Ad-hoc trading in addresses would lead to fragmented patterns of allocation that would vastly expand the global routing table, resulting in severe routing problems for many network operators which still use older routers with limited forwarding information base memory or low-powered routing processors. This large cost placed on everyone who uses the Internet by those that buy/sell IP addresses is a negative economic externality that any market would need to correct for.
  • Trading in IP blocks that are large enough to prevent fragmentation problems would reduce the number of potentially tradeable units to a few million at most.
  • The cost of changing from one set of IP addresses to another is very high, reducing the market liquidity. Organizations that can potentially reorganize their usage of IP addresses to free them up so that they can be sold will demand a high price and, once bought, will not be resold without a large profit. The cost of renumbering an organization's IP address space each time is comparable to the cost of switching to IPv6 once.[citation needed]

Long-term solution

The deployment of IPv6 is widely agreed to be the only currently viable solution to the IPv4 address shortage.[63] IPv6 is endorsed and implemented by all Internet technical standards bodies and network equipment vendors.[citation needed] It encompassed many design improvements, including the replacement of the 32-bit IPv4 address format, which allows 4.3 billion possible addresses, with a 128-bit address for a theoretical capacity of 3.4×1038 addresses. IPv6 has been in active production deployment since June 2006, when organized worldwide efforts of testing and evaluation (6bone) ceased.

See also

References

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  3. ^ RFC 4632
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  53. ^ V. Fuller, E. Lear, D. Meyer (2008-03-24). "Reclassifying 240/4 as usable unicast address space (expired draft)". IETF. Retrieved 2010-11-10.{{cite web}}: CS1 maint: multiple names: authors list (link)
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  55. ^ Hain, Tony. "A Pragmatic Report on IPv4 Address Space Consumption". Retrieved 2007-11-14.
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  61. ^ Yamagata, I.; Miyakawa, S.; Nakagawa, A,; Ashida, H. "Common requirements for IP address sharing schemes". IETF. July 12, 2010. Retrieved December 3, 2010.
  62. ^ RFC 2008
  63. ^ "Two /8s allocated to APNIC from IANA". APNIC. 2010-01-01. Retrieved 2011-02-03.