Some large /8 blocks of

IPv4 address Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. IPv4 was the first version d ...

es, the former Class A network blocks, are assigned in whole to single organizations or related groups of organizations, either by the

Internet Corporation for Assigned Names and Numbers The Internet Corporation for Assigned Names and Numbers (ICANN ) is an American multistakeholder group and nonprofit organization responsible for coordinating the maintenance and procedures of several databases related to the namespaces ...

(ICANN), through the

Internet Assigned Numbers Authority The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Inte ...

(IANA), or a regional Internet registry. Each /8 block contains 256 = 2 = 16,777,216 addresses, which covers the whole range of the last three delimited segments of an IP address. As

IPv4 address exhaustion IPv4 address exhaustion is the depletion of the pool of unallocated IPv4 addresses. Because the original Internet architecture had fewer than 4.3 billion addresses available, depletion has been anticipated since the late 1980s, when the Interne ...

has advanced to its final stages, some organizations, such as Stanford University, formerly using 36.0.0.0/8, have returned their allocated blocks (in this case to

APNIC APNIC (the Asia Pacific Network Information Centre) is the regional Internet address registry ( RIR) for the Asia-Pacific region. It is one of the world's five RIRs and is part of the Number Resource Organization ( NRO). APNIC provides numb ...

) to assist in the delay of the exhaustion date.

List of reserved /8 blocks

List of assigned /8 blocks to commercial organisations

List of assigned /8 blocks to the
United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national sec ...

List of assigned /8 blocks to the regional Internet registries

The regional Internet registries (RIR) allocate IPs within a particular region of the world. Note that this list may not include current assignments of /8 blocks to all

regional In geography, regions, otherwise referred to as zones, lands or territories, are areas that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and the interaction of humanity and t ...

or national Internet registries.

Original list of IPv4 assigned address blocks

The original list of IPv4 address blocks can be found in RFC 790 ( J. B. Postel, September 1981). In previous versions of the document, (RFC 776 (J. B. Postel, January 1981), RFC 750, (J. B. Postel, 26 September 1978)), network numbers were 8-bit numbers rather than the 32-bit numbers used in IPv4. RFC 790 also added three networks not listed in RFC 776: 42.rrr.rrr.rrr, 43.rrr.rrr.rrr, and 44.rrr.rrr.rrr. The relevant portion of RFC 790 is reproduced here with minor changes: :* 000.rrr.rrr.rrr Reserved BP:* 001.rrr.rrr.rrr BBN-PR BBN Packet Radio Network CA2:* 002.rrr.rrr.rrr SF-PR-1 SF Packet Radio Network EM:* 003.rrr.rrr.rrr BBN-RCC BBN RCC Network GC:* 004.rrr.rrr.rrr SATNET Atlantic Satellite Network M11:* 005.rrr.rrr.rrr SILL-PR Ft. Sill Packet Radio Network EM:* 006.rrr.rrr.rrr SF-PR-2 SF Packet Radio Network EM:* 007.rrr.rrr.rrr CHAOS MIT CHAOS Network OON:* 008.rrr.rrr.rrr CLARKNET SATNET subnet for Clarksburg M11:* 009.rrr.rrr.rrr BRAGG-PR Ft. Bragg Packet Radio Net EM:* 010.rrr.rrr.rrr

ARPANET The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical fou ...

ARPANET VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 011.rrr.rrr.rrr UCLNET University College London K:* 012.rrr.rrr.rrr CYCLADES CYCLADES VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 013.rrr.rrr.rrr Unassigned BP:* 014.rrr.rrr.rrr TELENET TELENET VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 015.rrr.rrr.rrr EPSS British Post Office EPSS K:* 016.rrr.rrr.rrr DATAPAC DATAPAC VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 017.rrr.rrr.rrr TRANSPAC TRANSPAC VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 018.rrr.rrr.rrr LCSNET MIT LCS Network [DDC2] :* 019.rrr.rrr.rrr TYMNET TYMNET VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 020.rrr.rrr.rrr DC-PR D.C. Packet Radio Network VGC.html" ;"title="Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC">Vint_Cerf.html" ;"title="/nowiki>Vint Cerf">VGC/nowiki> :* 021.rrr.rrr.rrr EDN DCEC EDN C5:* 022.rrr.rrr.rrr DIALNET DIALNET RC:* 023.rrr.rrr.rrr MITRE MITRE Cablenet [APS] :* 024.rrr.rrr.rrr BBN-LOCAL BBN Local Network GC:* 025.rrr.rrr.rrr RSRE-PPSN RSRE / PPSN D2:* 026.rrr.rrr.rrr AUTODIN-II AUTODIN II C5:* 027.rrr.rrr.rrr NOSC-LCCN NOSC / LCCN TP:* 028.rrr.rrr.rrr WIDEBAND Wide Band Satellite Network JW2:* 029.rrr.rrr.rrr DCN-COMSAT COMSAT Dist. Comp. Network LM1:* 030.rrr.rrr.rrr DCN-UCL UCL Dist. Comp. Network K:* 031.rrr.rrr.rrr BBN-SAT-TEST BBN SATNET Test Network M11:* 032.rrr.rrr.rrr UCL-CR1 UCL Cambridge Ring 1 K:* 033.rrr.rrr.rrr UCL-CR2 UCL Cambridge Ring 2 K:* 034.rrr.rrr.rrr MATNET Mobile Access Terminal Net M11:* 035.rrr.rrr.rrr NULL UCL/RSRE Null Network D2:* 036.rrr.rrr.rrr SU-NET Stanford University Ethernet RC:* 037.rrr.rrr.rrr DECNET Digital Equipment Network RL:* 038.rrr.rrr.rrr DECNET-TEST Test Digital Equipment Net RL:* 039.rrr.rrr.rrr SRINET SRI Local Network EOF:* 040.rrr.rrr.rrr CISLNET CISL Multics Network H2:* 041.rrr.rrr.rrr BBN-LN-TEST BBN Local Network Testbed TP:* 042.rrr.rrr.rrr S1NET LLL-S1-NET AK:* 043.rrr.rrr.rrr INTELPOST COMSAT INTELPOST LM1:* 044.rrr.rrr.rrr

AMPRNET The AMPRNet (AMateur Packet Radio Network) or Network 44 is used in amateur radio for packet radio and digital communications between computer networks managed by amateur radio operators. Like other amateur radio frequency allocations, an IP r ...

Amateur Radio Experiment Net HM.html" ;"title="Hank_Magnuski.html" ;"title="/nowiki>Hank Magnuski">HM">Hank_Magnuski.html" ;"title="/nowiki>Hank Magnuski">HM/nowiki>

Notes

References

* The authoritative up-to-date list of IANA assignments. * * Historical IP address lists: ** First version of IANA table with historical notes via the

Internet Archive The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge". It provides free public access to collections of digitized materials, including websites, software applications/games, music, ...

Wayback Machine The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive, a nonprofit based in San Francisco, California. Created in 1996 and launched to the public in 2001, it allows the user to go "back in time" and see ...

. ** Last version of IANA table with historical notes via the