IPv4 address exhaustion

1. IPv4 address exhaustion http://en.wikipedia.org/wiki/IPv4_address_exhaustion

2. What exactly is "IPv4 exhaustion"? • IPv4 exhaustion doesn’t mean that the Internet will stop working. • Instead, IPv4 exhaustion is the term used to describe when there will be no more unallocated IPv4 addresses available. • But this will happen is several stages, and not necessarily in the order below: • IANA exhausted its IPv4 free pool (3 Feb 2011) • RIRs exhaust their unallocated pools • Expanding networks (ISPs, businesses, etc) exhaust their pools of unused addresses

3. IPv4 address exhaustion • Depletion of the pool of unallocated IPv4 (Internet Protocol Version 4) addresses. • The IP address space is managed by the Internet Assigned Numbers Authority(IANA) globally, and by five regional Internet registries (RIRs) responsible in their designated territories for assignment to end users and local Internet registries, such as Internet service providers. • IANA also manages autonomous system (AS) numbers,root zonemanagement in the Domain Name System (DNS), media types, and other IP-related symbols and numbers • IANA is operated by the Internet Corporation for Assigned Names and Numbers, ICANN.

4. Regional Internet Registry (RIR) • An organization that manages the allocation and registration of Internet number resources within a particular region of the world. • Internet number resources include IP addresses and autonomous system (AS) numbers. • twnicin Taiwan (www.twnic.net.tw)

5. Regional Internet Registry (RIR) • African Network Information Centre (AfriNIC): • Africa • American Registry for Internet Numbers (ARIN): • the United States, Canada, and several parts of the Caribbean region. • Asia-Pacific Network Information Centre (APNIC): • Asia, Australia, New Zealand, and neighboring countries • Latin America and Caribbean Network Information Centre (LACNIC): • Latin America and parts of the Caribbean region • Réseaux IP Européens Network Coordination Centre (RIPE): • Europe, the Middle East, and Central Asia

6. IPv4 address exhaustion • On 31 January 2011, the last two unreserved IANA /8 address blocks were allocated to APNIC according to RIR request procedures. • This left five reserved but unallocated /8 blocks. In accord with ICANN policies, IANA proceeded to allocate one of those five /8s to each RIR, exhausting the IANA pool

7. IPv4 address exhaustion • At a news conference in Miami (February 3, 2011) the ICANN announced (released-PDF) that it has distributed the last batch of its remaining IPv4 addresses to the world’s five RIRs that manage IP addresses in different regions. These Registries will begin assigning the final IPv4 addresses within their regions until they run out completely. • APNIC is expected to be the first RIR to exhaust its allocated pool with assignment to customers in mid-2011, Europe will be next, probably towards the end of 2011, and North America will follow sometime in 2012. • APNIC IPv4 exhaustion details (link)

8. APNIC IPv4 exhaustion The policy aims to ensure that new and emerging networks can continue to receive a small amount of IPv4 for many years to come so they can connect to both IPv4 and IPv6 networks during the transition to IPv6. Under this policy, Asia Pacific organizations can each request one, and only one, small slice (a /22, or 1024 addresses) of the final /8. There are a total of around 16,000 small slices that can be given out from this final /8. Currently, APNIC has around 3000 account holders and had a membership growth rate of 300 new accounts during the past year.  In addition, each year, APNIC receives a number of returned addresses as businesses close down. APNIC will continue to recycle these addresses and make them available to account holders.

9. APNIC IPs exhaustion • As of March 6, 2011, APNIC had 3.89 /8 blocks left. APNIC used 1.4 /8 blocks in January 2011. • The last /8 block • APNIC continue normal allocation until the last free /8 block. • Then, only allocate one /22 block(1024 IPs, minimum allocation size), to eachlocal Internet registry (LIR). • Typically, 99.2% of address space is allocated in larger blocks, accounting for 57% of allocations. • Currently 3000 LIRs in APNIC, 300 new LIRs added in 2010. Due to 16384 /22 blocks in final /8 block, this last /8 block expects to last for many yearsto assist deployment of IPv6. • The time when APNIC reaches its final /8 block is generally regarded as the main exhaustion event in IPv4 history, as LIR organizations will have a much harder time getting their new systems or customers publicly online on IPv4. • Moreover, the 300 new large and small LIRs per year at APNIC will only be able to obtain 1024 addresses from APNIC. This will have an impact on all organizations and their customers worldwide due to the requirement for inter-network communication.

10. APNIC IPs exhaustion • Predictions • APNIC announced on 1/31/2011, it expects to be down to the last /8 within three to six months. Geoff Huston's (APNIC) daily generated report currently predicts August. • The predicted date has however steadily been getting earlier in the last year, with the exhaustion date trending to May or June (Moreover, his analysis wrongly assumes no special policy for the last /8 which will be reached earlier than the specified date). • Tony Haine (Cisco Systems) is making semi-weekly updated graphs predicting mid-April. (His analysis does however not consider the use of the 1.57 /8 blocks from the various/legacy pool.) Stephan Lagerholm's depletion-Tool is daily updated and predicts August in its default setting.

11. APNIC IPs exhaustion • RIR-shopping • When APNIC has only one /8 available, some organizations that usually request address space from APNIC but have a presence in another territory may try to get address space from another RIR. • RIR-shopping is viewed unfavorably in many policy discussions, and many users of large address space, such as ISPs with residential customers, have no significant presence abroad. Transfer from other RIRs are currently not allowed, but are under discussion at ARIN as Proposal PP 119.

12. Endgame for IPs exhaustion • By 2008, policy planning for the end-game and post-exhaustion era. • Several proposals have been discussed to mitigate end game shortages of IPv4 addresses. • Reclamation of unused IPv4 space • IANA could potentially re-claim/re-issue the under-utilized ranges in smaller blocks, the transfer policy from ARIN/RIPE/APNIC. • Drawback: expensive and time-consuming to re-number a large network since organizations will likely object, with legal conflicts possible. Even if all IPs were reclaimed, it would only postpone the date of address exhaustion. • IP blocks have been allocated to entities that no longer exist or never used. No strict accounting of IP allocations has been undertaken, need a big effort to track down unused IPs, as many are only in use on intranets.

13. Endgame for IPs exhaustion • Reclamation of unused IPv4 space • Some previously reserved blocks by IANA have been added to available pool. • proposals to use class E network IPs(240.0.0.0/4), • but many computer and routeroperating systems and firmware can’t use these IPs. • For this reason, the proposals have sought not to designate 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 IPs. Notably, Stanford University relinquished their Class A IP block in 2000, making 16million IPs available. Other organizations done so include the US DoD, BBN Technologies, and Interop.

14. Endgame for IPs exhaustion • ISP-wide network address translation (NAT) • When ISPs implement NAT within their network, they may allocate private addresses to customers and need only one global scope address for a potentially large group of customers. • customers must use gateway for traffic to Internet. • successfully implemented in country like Russia, where many broadband providers now use Carrier GradeNAT, offer publicly routable IP at an additional cost • Research In Motion (RIM),BlackBerry maker, currently routes all Blackberry data to central network operating centers for encryption and decryption purposes; reducing the number of public IPs assigned. • However, ISP-wide NAT is not scalable, and limited to the number of ports available (approximately 65000) in the Transport Layer protocols. • NAT is not suitable for all applications

15. Endgame for IPs exhaustion • Markets in IP addresses • Create markets to buy and sell IPs, been proposed many times as an efficient means of allocation. • primary benefit is IPs would continue to be available. major drawbacks prevent their implementation follow: • only delay IP exhaustion for a relatively short time, since the public Internet is still growing. • The concept of legal IP "ownership" as property is explicitly denied by ARIN/RIPE/ARIN NCC policy 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.

16. Endgame for IPs exhaustion • Markets in IP addresses • Ad-hoc IP trading would lead to fragmented patterns of allocation, then vastly expand 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 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 IPs to another is very high, reducing market liquidity. 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.

17. Endgame for IPs exhaustion • IPv6

18. IPv4 address exhaustion • The anticipated shortage has been the driving factor in creating and adopting several new technologies, including • Classless Inter-Domain Routing (CIDR) in 1993, • network address translation (NAT), • Internet Protocol, IPv6, in 1998, • Use of private network addressing, • Name-based virtual hosting of web sites, • Tighter control by regional Internet registries on allocating addresses to local Internet registries, • Network renumbering and subnetting to reclaim large blocks of address space allocated in the early days of the Internet

19. IPv4 address exhaustion • 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.

20. IPv4 address exhaustion • Mobile devices • IPv4 is the de facto standard for networked digital communication with low cost for embedding substantial computing power into hand-held devices dropped. • Mobile phones have become viable Internet hosts. New specifications of 4G devices require IPv6 addressing. • Internet demographics • For the developed world, in 1990, only a small fraction had Internet connectivity. Just 15 years later, almost half of them had persistent broadband connections. Internet users in countries (China and India) are also driving address exhaustion.

21. IPv4 address exhaustion • Always-on connections • Throughout the 1990s, the predominant Internet access was telephone modem dial-up. The rapid growth of the dial-up networks increased address consumption rates, although modem pools, and as a result, the pool of assigned IP addresses, were shared amongst a larger customer base. • By 2007, broadband Internet access had exceed 50% penetration in many markets. 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.

22. IPv4 address exhaustion • Inefficient address use • Organizations (1980s) were often allocated far more IPs than needed, because initial method was inadequate to reflect reasonable usage, e.g., large companies or universities were assigned class A blocks, because class B block was too small. • Organizations’s public IPs are not accessible outside LAN. From a global address allocation viewpoint, this is inefficient, but scenarios exist where this is preferred in organizational network implementation strategies. • Due to inefficiencies of subnetting, difficult to use all addresses in a block. Host-density ratio (RFC 3194) a IP utilization metric. • 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.

23. IPv4 Subnet Classes