Internet addressing growth map.

IP address exhaustion refers to the decreasing availability of publicly available IPv4 IP addresses. This has been a concern that has spanned decades since the 1980s. As a result, this has been the driving factor in creating and adopting several new technologies, including classful networks, CIDR addressing, and IPv6 and has been significant in the wide adoption of Network Address Translation (NAT). Image File history File links Size of this preview: 800 × 390 pixelsFull resolution (1279 × 624 pixel, file size: 30 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 390 pixelsFull resolution (1279 × 624 pixel, file size: 30 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Internet Protocol version 4 is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. ... This article or section does not cite any references or sources. ... Classful networking is the name given to the first round of changes to the structure of the IP address in IPv4. ... Warning! This Article contains disinformation. ... Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched internetworks. ... In Computer Networking, the process of Network Address Translation (NAT, also known as Network Masquerading, Native Address Translation or IP Masquerading) involves re-writing the source and/or destination addresses of IP packets as they pass through a Router or firewall. ...

As of 2007, IPv6 is generally seen as the only long-term solution for IPv4 address exhaustion, but is only being adopted very slowly. As the deadline for IPv4 address exhaustion approaches, most ISPs and equipment vendors are only just starting to consider widespread deployment of IPv6.

Synopsis

Every host on a network, such as a computer or networked printer, is assigned a unique IP address that is used to communicate with other hosts on that network normally expressed in dotted decimal format (for example 66.230.200.110). Each octet, or part of the address, must be a number from 0 to 255 and therefore there is a logical maximum of 4,294,967,296 addresses available for use. However large numbers of addresses are reserved for local use and are unavailable for Internet use. This article is about the machine. ... A computer printer, or more commonly a printer, produces a hard copy (permanent human-readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper transparencies. ...

There are nowhere near enough IPV4 addresses on the public Internet to provide one to each computer or other device requiring Internet access. This problem is largely solved by network address translation (NAT), whereby a single public Internet IP address can be shared by multiple internal local area network (LAN) hosts. Data sent by individual hosts to the Internet states its source address as the public IP address used, and the router providing the access is able to keep track of which host originated the traffic inside the network and forward replies accordingly. This is similar to multiple office telephones that share one phone number, and each have an extension number to distinguish individual telephones. In Computer Networking, the process of Network Address Translation (NAT, also known as Network Masquerading, Native Address Translation or IP Masquerading) involves re-writing the source and/or destination addresses of IP packets as they pass through a Router or firewall. ... “LAN” redirects here. ... This article is about a computer networking device. ...

Causes

Today, there are several driving forces behind IPv4 address exhaustion:

• Mobile devices — laptop computers, personal digital assistants, mobile phones
• Always-on devices — Broadband
• Rapidly growing number of Internet users
• Inefficient use by many organisations

Laptop with touchpad. ... Look up Personal digital assistant in Wiktionary, the free dictionary. ... A WildBlue Satellite Internet dish. ...

Inefficient address use

Many organizations have obtained IP addresses blocks far larger than they require, especially during the 1980s and early 1990s where there was generally little concern for a potential shortage of IP addresses. For example, large companies or universities were given /8 address blocks which each contain 16 million IPv4 addresses. Many organisations continue to utilise public IP addresses for devices not accessible outside their local network and would be well served by a NAT based implementation, releasing potentially large ranges of IP addresses for re-allocation. Some organisations also have large ranges of IP addresses currently not utilised but which have not been released back to the allocation authorities for various reasons (profiteering being one possible motivator).

Due to inefficiencies caused by subnetting, it is very difficult to use all the addresses in a block. The HD Ratio defines an intuitive metric for utilization of IP address blocks. A graphic representation of relationships and source of the various variables representing a chunk of C subnets In computer networks, a subnetwork or subnet is a range of logical addresses within the address space that is assigned to an organization. ...

Mitigation

Some things that can be done to mitigate the IPv4 address exhaustion are (not mutually exclusive):

• Network address translation (NAT)
• Use of private networks
• Dynamic Host Configuration Protocol (DHCP)
• Named based virtual hosting
• Tighter control by regional Internet registries on the allocation of addresses to local Internet registries
• Network renumbering to reclaim large blocks of address space allocated in the early days of the Internet

In Computer Networking, the process of Network Address Translation (NAT, also known as Network Masquerading, Native Address Translation or IP Masquerading) involves re-writing the source and/or destination addresses of IP packets as they pass through a Router or firewall. ... It has been suggested that RFC 1918 be merged into this article or section. ... (DHCP) is a set of rules used by a communications device such as a computer, router or network adapter to allow the device to request and obtain an IP address from a server which has a list of addresses available for assignment. ... It has been suggested that this article or section be merged into shared web hosting service. ... A Regional Internet Registry (RIR) is an organisation overseeing the allocation and registration of Internet number resources within a particular region of the world. ...

Conservation

"Conservation" is another method used to preserve available IP addresses. Upon conception of the Internet it was never envisaged that it would require anywhere near as many IP addresses as it now does; therefore they were frequently allocated in 'blocks' of 255, 65536, or 16777216 addresses for use. To this day several organisations have been assigned 16 million IP addresses of which they use a comparative handful. These days organisations responsible for allocation of public IP addresses are much more reluctant to assign large groups.

Subnetting

Subnetting is again another method used to get more use out of IP addresses generally, in short the dotted decimal notation is a user-friendly method of representing binary addresses such as 01000010111001101100100001101110 (again 66.230.200.110). These addresses are subnetted by applying a subnet mask which denotes which portion of the address is the network portion and which is the host portion; this is analogous to the area code and subscriber number of a telephone number, the phone number (212) 555-9293 is uniquely identifiable from (213) 555-9293. This allows the same numbers to be used in multiple locations with only some minor extra consideration. The word subnetwork has two related meanings. ... The binary numeral system, or base-2 number system, is a numeral system that represents numeric values using two symbols, usually 0 and 1. ... A subnet mask is a method of hiding or masking the network address portion of an IP address. ...

Reclaiming unused IPv4 space

In the early days of the Internet, before the creation of classful networks and later CIDR addressing, large blocks of IP addresses were allocated to individual companies and organizations. It is often suggested that these allocations should be reclaimed by IANA and reissued to others. However, it can cost a great deal of time and money to renumber a network so these organizations will likely object, quite possibly to the point of filing lawsuits. Moreover, at the current rate of IPv4 address consumption, even if all of these could be reclaimed, it would result in only extending the address exhaustion date back a year or two. Classful networking is the name given to the first round of changes to the structure of the IP address in IPv4. ... Warning! This Article contains disinformation. ... The Internet Assigned Numbers Authority (IANA) is the entity that oversees global IP address allocation, DNS root zone management, and other Internet protocol assignments. ...

Similarly, many IP address have been allocated to companies that no longer exist or were never used. Unfortunately, the stricter accounting of IP address allocation currently in place wasn't always in place and it would take quite a bit of effort to track down which addresses really are unused. Many IP addresses that do not show up in the public BGP routing tables are actually in use on intranets. Again, it is likely that more time would be spent tracking down which IP address could be reclaimed than would extend the exhaustion date. The border gateway protocol (BGP) is one of the core routing protocols in the Internet. ... An intranet is a private computer network that uses Internet protocols, network connectivity to securely share part of an organizations information or operations with its employees. ...

Finally, some have suggested using IP addresses that are currently reserved by IANA, such as the form class E network addresses. Unfortunately, there are many operating systems, routers and other software that would need to be modified or upgraded in order for them to be usable. The effort to do this would likely be as great, if not greater, than switching to IPv6. Classful networking is the name given to the first round of changes to the structure of the IP address in IPv4. ... An operating system (OS) is the software that manages the sharing of the resources of a computer and provides programmers with an interface used to access those resources. ... This article is about a computer networking device. ...

ISP wide NAT

Similar to how many companies use NAT for most employee computers, ISP can use NAT for most customers instead of giving them publicly routable dynamically assigned IP addresses. This has many cost-saving and revenue-enhancing advantages to ISP, including dramatically reducing their need for IPv4 addresses, easier blocking of 'unauthorized' servers running on customer computers such as file sharing systems, the use of web proxies to reduce bandwidth usage and add new banner ads, control of which enhanced services are allowed such as VoIP and games, benefits of customer-wide firewalls, enforcement of laws covering content and tracking, etc. ISPs may allow customers to purchase, at an extra cost, publicly routable dynamic IP addresses similar to how they currently allow, at an extra cost, static IP addresses.

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, although the market price of addresses would be expected to rise over time. These schemes have major drawbacks that have prevented their implementation:

• The concept of legal "ownership" of IP addresses as property is questionable.
• Ad-hoc trading in addresses would lead to fragmented patterns of allocation that would vastly expand the routing table, resulting in severe routing problems for many networks which still use older routers with limited FIB memory or low-powered routing processors.
• The administration of such a scheme would be incompatible with current working practices.
• Creation of a market requires a critical mass of buyers and sellers. Without that, there will not be price stability. And without an expectation of price stability, it is unlikely that companies will support formation of such a market.
• The intrinsic value of IP addresses is really quite low. There isn't enough margin for market mechanisms, i.e. brokers, to be profitable.
• The creation of a market in IPv4 addresses would only delay the practical exhaustion of the IPv4 address space for a relatively short time, as absolute exhaustion of the IPv4 space would follow within at most a couple of years after the exhaustion of addresses for new allocations.

Exhaustion date

This article or section may contain proseline. Please help convert this timeline into prose or, if necessary, a list.

Exhaustion will occur on all continents at the same time, as all registries follow similar allocation policies, with for about 12 to 18 months stock allocated at each request. Only specific organisations which requested addresses in the pre-CIDR or pre-RIR era's possibly have a significant stock left. Image File history File links Broom_icon. ... Prose is writing distinguished from poetry by its greater variety of rhythm and its closer resemblance to the patterns of everyday speech. ... Classless Inter-Domain Routing (CIDR), introduced starting in 1993, is the latest refinement to the way IP addresses are interpreted. ... Possible meanings: Regional Internet Registry Richmond International Raceway Riverside International Raceway Riverside (Rubidoux) Airport Royal Irish Regiment This page concerning a three-letter acronym or abbreviation is a disambiguation page—a list of articles associated with the same title. ...

As of September 2007, Geoff Huston of APNIC predicts with detailed simulations an exhaustion of the unallocated IANA pool in August 2010.^[1] Tony Hain of Cisco Systems predicts the exhaustion date to be around April 2010.^[2] These predictions are derived from current trends, and do not take into account any last chance rush to acquire the last available addresses. Within 10 months after the IANA pool exhaustion, every regional Internet registry (RIR) will have exhausted their last assigned addresses (most earlier). These dates lie within a depreciation time of five years of network equipment that is currently being acquired. The office building that houses APNIC in Brisbane, Australia. ... “Cisco” redirects here. ... The Internet Assigned Numbers Authority (IANA) is an organisation that oversees IP address, top level domain and Internet protocol code point allocations. ... A Regional Internet Registry (RIR) is an organisation overseeing the allocation and registration of Internet number resources within a particular region of the world. ...

On May 21, 2007, the American Registry for Internet Numbers (ARIN), the North 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".^[3] It should be noted that "applications" include general connectivity between devices on the Internet, as some devices only have an IPv6 address allocated. The American Registry for Internet Numbers (ARIN) is the Regional Internet Registry (RIR) for Canada, the United States, and portions of the Caribbean. ...

On June 20, 2007, the Latin American and Caribbean Internet Addresses Registry (LACNIC), the South American RIR, advised "preparing its regional networks for IPv6" by January 1, 2011 for the exhaustion of IPv4 addresses "in three years time".^[4] The Latin American and Caribbean Internet Addresses Registry (LACNIC) is the Regional Internet Registry for Latin America and the Caribbean. ...

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.^[5][6] The office building that houses APNIC in Brisbane, Australia. ... The Japan Network Information Center (JPNIC) is the National Internet Registry in Japan that manages several aspects of internet operations, including the allocation of IP addresses and AS numbers. ...

Less than four years until the first RIR exhaustion is a short time for the entire industry to transition to IPv6. This situation is aggravated by the fact that until exhaustion there will be no significant demand. 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." Geoff Huston claims we should have started the transition to Ipv6 much earlier, such that by the exhaustion date it would be completed.

IPv6 as a long-term solution

IPv6 is intended to be the long-term solution to the IPv4 address shortage. Instead of a 32 bit address, with 4.3 billion possibilities, IPv6 represents addresses as 128 bit addresses, providing 3.4×10³⁸ or logically 50 octillion for each of the roughly 6.5 billion people on Earth. Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched internetworks. ... Main article: Names of large numbers A octillion is a number written as either: a 1 followed by 27 zeros (10 to the 27th power, as used in the short scale system of numeration. ...

IPv6 readiness

Most equipment such as hosts and routers require explicit IPv6 support. The main exception is equipment which only does low-level transport, such as cables, most ethernet adapters, and most layer 2 switches.

As of 2007, IPv6 readiness is currently not considered in most purchasing decisions. If such equipment is not IPv6-capable, it might need to be upgraded or replaced prematurely if connectivity from or to new users and to servers using IPv6 addresses is required.

As with the year-2000 compatibility, IPv6 compatibility is mainly a software/firmware issue. However, unlike the year-2000 issue, there seems to be virtually no effort to ensure compatibility of older equipment and software by manufacturers. Furthermore, even compatibility of products now available is unlikely for many types of software and equipment. This is caused by only a recent realisation that IPv4 exhaustion is imminent, and the hope that we will be able to get by for a relatively long time with a combined IPv4/IPv6 situation. There is a tug-of-war going on in the internet community whether the transition will/should be rapid or long. Specifically, an important question is whether almost all internet servers should be ready to serve to new IPv6-only clients by 2011.

Most equipment would be fully IPv6 capable with a software/firmware update. However, as with 64-bit windows and Wi-Fi Protected Access support, manufacturers might try to save on development cost for hardware which they are no longer selling, and try to get more sales from new "IPv6-ready" equipment. Even when chipset makers develop new drivers for their chipsets, device manufacturers might not pass these on to the consumers. Moreover, as IPv6 gets implemented, optional features might become really important, such as IPv6 mobile. It is therefore important to check your supplier on its support record, and get guarantees if you can or need to. Examples of equipment which currently usually are not IPv6 ready, are home routers. As for the CableLabs consortium, the 160 Mbit/s DOCSIS 3.0 IPv6-ready specification for cable modems has only been issued in August 2006. IPv6 capable Docsis 2.0b was skipped. It is expected that only 60% of cable modems' servers and 40% of cable modems will be IPv6-ready by 2011 ^[7]. Other equipment which is typically not ipv6-ready range from skype and sip phones to oscilloscopes and printers. Professional network routers in use should be IPv6-ready. Most personal computers should also be IPv6-ready, because the network stack resides in the operating system. Most applications with network capabilities are not ready, but could be upgraded with support from the developers. Since February 2002, with J2SE 1.4, all applications that are 100% java have implicit support for IPv6 addresses^[8]. The Windows API, informally WinAPI, is the name given by Microsoft to the core set of application programming interfaces (APIs) available in the Microsoft Windows operating systems. ... Wi-Fi Protected Access (WPA and WPA2) is a class of systems to secure wireless (Wi-Fi) computer networks. ... Cable Television Laboratories, Inc. ... Data Over Cable Service Interface Specifications (DOCSIS) is an international standard developed by CableLabs and contributing companies that include: ARRIS, BigBand Networks, Broadcom, Cisco, Conexant, Correlant, Intel, Motorola, Netgear, Terayon, and Texas Instruments. ... An outdated model of the Motorola Surfboard cable modem A cable modem is a type of modem that provides access to a data signal sent over the cable television infrastructure. ... Skype (IPA pronunciation: , rhymes with type) is a software program created by the entrepreneurs Niklas Zennström and Janus Friis. ... Look up sip in Wiktionary, the free dictionary. ...

For ADSL services, a problem can be that the access networks of the incumbent telephone connection are not IPv6 compatible, such that independent ADSL providers cannot provide native IPv6 connectivity.

References

1. ^ Huston, Geoff. IPv4 Address Report, daily generated. Retrieved on 2007-09-30.
2. ^ Hain, Tony. IPv4 Address Pool, quarterly generated. Retrieved on 2007-07-01.
3. ^ American Registry for Internet Numbers (ARIN) (2007-05-21). ARIN Board Advises Internet Community on Migration to IPv6 (in English). Press release. Retrieved on 2007-07-01.
4. ^ Latin American and Caribbean Internet Addresses Registry (LACNIC) (2007-06-21). LACNIC announces the imminent depletion of the IPv4 addresses (in English). Press release. Retrieved on 2007-07-01.
5. ^ Asia-Pacific Network Information Centre (APNIC) (2007-06-26). JPNIC releases statement on IPv4 consumption (in English). Press release. Retrieved on 2007-07-01.
6. ^ Japan Network Information Center (JPNIC) (2007-06-19). About IPv4 address exhaustion in Internet Registries (in Japanese). Press release. Retrieved on 2007-07-01.
7. ^ ABI Research (2007-08-23). DOCSIS 3.0 Network Equipment Penetration to Reach 60% by 2011 (in English). Press release. Retrieved on 2007-09-30.
8. ^ Networking IPv6 User Guide for JDK/JRE 5.0. Retrieved on 2007-09-30.

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 273rd day of the year (274th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 182nd day of the year (183rd in leap years) in the Gregorian calendar. ... The American Registry for Internet Numbers (ARIN) is the Regional Internet Registry (RIR) for Canada, the United States, and portions of the Caribbean. ... For information on Wikipedia press releases, see Wikipedia:Press releases. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 182nd day of the year (183rd in leap years) in the Gregorian calendar. ... The Latin American and Caribbean Internet Addresses Registry (LACNIC) is the Regional Internet Registry for Latin America and the Caribbean. ... For information on Wikipedia press releases, see Wikipedia:Press releases. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 182nd day of the year (183rd in leap years) in the Gregorian calendar. ... The office building that houses APNIC in Brisbane, Australia. ... For information on Wikipedia press releases, see Wikipedia:Press releases. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 182nd day of the year (183rd in leap years) in the Gregorian calendar. ... The Japan Network Information Center (JPNIC) is the National Internet Registry in Japan that manages several aspects of internet operations, including the allocation of IP addresses and AS numbers. ... For information on Wikipedia press releases, see Wikipedia:Press releases. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 182nd day of the year (183rd in leap years) in the Gregorian calendar. ... For information on Wikipedia press releases, see Wikipedia:Press releases. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 273rd day of the year (274th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 273rd day of the year (274th in leap years) in the Gregorian calendar. ...

External Links

• Official current state of IPv4 /8 allocations, as maintained by IANA
• A Pragmatic Report on IPv4 Address Space Consumption by Tony Hain (Cisco) as of September 2005.
• Dealing with IPv4 address exhaustion - commentary on JPNIC policy proposal