List of assigned /8 IPv4 address blocks
Some large /8 blocks of IP addresses, 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 (ICANN), through the Internet Assigned Numbers Authority (IANA), or a regional Internet registry.
Each /8 block contains 16,777,216 addresses.
As IPv4 address exhaustion has advanced to its final stages, some organizations, such as Stanford University, formerly using 18.104.22.168/8, have returned their allocated blocks to assist in the delay of the exhaustion date.
List of assigned /8 blocks 
|Block||Organization||IANA Date||RIR Date||Notes|
|0.0.0.0/8||IANA - Local Identification||1981-09||Originally IANA - Reserved 1981-09. 0.0.0.0/8 reserved for self-identification (RFC 5735).|
|22.214.171.124/8||APNIC||2010-01||Formerly IANA - Reserved 1981-09.|
|126.96.36.199/8||RIPE NCC||2009-10||Formerly IANA - Reserved 1981-09.|
|188.8.131.52/8||General Electric Company||1994-05||1988-02-23|
|184.108.40.206/8||Level 3 Communications, Inc.||1992-12||1992-12-01||Originally Bolt Beranek and Newman Inc. (then GTE, then Genuity) 1992-12. Updated to Level 3 Communications, Inc. in 2007-04.|
|220.127.116.11/8||RIPE NCC||Formerly IANA - Reserved 1995-07.|
|18.104.22.168/8||Army Information Systems Center||1994-02||1994-02-01||Headquarters, USAISC.|
|22.214.171.124/8||Administered by ARIN||1995-04||1997-11-24||Formerly IANA - Reserved 1995-04. Entirely assigned to DoD Network Information Center (DNIC) 1997-11-24. Updated to Administered by ARIN not before 2007.|
|126.96.36.199/8||Level 3 Communications, Inc.||1992-12||1992-12-01||Originally Bolt Beranek and Newman Inc. (then GTE, then Genuity) 1992-12. Updated to Level 3 Communications, Inc. in 2007-04.|
|10.0.0.0/8||IANA - Private Use||1995-06||Reserved for Private-Use Networks (RFC 1918).|
|188.8.131.52/8||DoD Intel Information Systems||1993-05||1984-01-19|
|184.108.40.206/8||AT&T Bell Laboratories||1995-06||1983-08-23|
|220.127.116.11/8||Xerox Corporation||1991-09||1986-04-25||Xerox Palo Alto Research Center (PARC).|
|18.104.22.168/8||APNIC||2010-04||Formerly IANA - Public Data Network 1991-06-01, then IANA - Reserved 2008-01-22. Returned to IANA in 2008. One of the Class A networks (22.214.171.124/8) was used to map between Internet Addresses and the Public Data Network Addresses (X.121). This network was reclaimed by IANA in 2007 and was subsequently re-allocated in 2010. See RFC 877 and RFC 1356 for historical information.|
|126.96.36.199/8||Digital Equipment Corporation||1994-11||1989-05-18||Digital Equipment Corporation, then Compaq, then Hewlett-Packard.|
|188.8.131.52/8||Ford Motor Company||1995-05||1988-06-15|
|184.108.40.206/8||Computer Sciences Corporation||1994-10||1989-09-04|
|220.127.116.11/8||DDN-RVN||1991-07||1991-07-01||DoD Network Information Center (DNIC).|
|18.104.22.168/8||Defense Information Systems Agency||1993-05||1989-06-26||DoD Network Information Center (DNIC).|
|22.214.171.124/8||ARIN||2010-11||Formerly IANA - Reserved 1995-07.|
|126.96.36.199/8||ARIN||2001-05||2001-05-01||Formerly IANA - Cable Block 1995-07, then ARIN - Cable Block 2001-05. Updated to ARIN not before 2007.|
|188.8.131.52/8||UK Ministry of Defence||1995-01||1985-01-28||Originally Royal Signals and Radar Establishment. Updated to UK Ministry of Defence in 2006-01.|
|184.108.40.206/8||Defense Information Systems Agency||1995-05||1995-05-01||DoD Network Information Center (DNIC).|
|220.127.116.11/8||APNIC||2010-01||Formerly IANA - Reserved 1995-04.|
|18.104.22.168/8||DSI-North||1992-07||DoD Network Information Center (DNIC).|
|22.214.171.124/8||Defense Information Systems Agency||1991-07||1991-07-01||DoD Network Information Center (DNIC).|
|126.96.36.199/8||Defense Information Systems Agency||1991-07||1991-07-01||DoD Network Information Center (DNIC).|
|188.8.131.52/8||RIPE NCC||2010-05||2010-05-18||Formerly IANA - Reserved 1991-04.|
|184.108.40.206/8||AT&T Global Network Services||1994-06||1990-05-30||Originally Norsk Informasjonsteknology. IBM acquired Norsk Informasjonsteknologi (Norway) in 1995. Updated to AT&T Global Network Services in 2007-08.|
|220.127.116.11/8||DLA Systems Automation Center||1991-01||1991-01-01||DoD Network Information Center (DNIC).|
|18.104.22.168/8||MERIT Computer Network||1994-04||1994-04-01|
|22.214.171.124/8||APNIC||2010-10||Formerly Stanford University 1993-04, then IANA - Reserved 2000-07.|
|126.96.36.199/8||RIPE NCC||2010-11||Formerly IANA - Reserved 1995-04.|
|188.8.131.52/8||PSINet, Inc.||1994-09||1991-04-16||PSINet, then Cogent Communications.|
|184.108.40.206/8||APNIC||2011-01||Formerly IANA - Reserved 1995-04.|
|220.127.116.11/8||Eli Lilly & Company||1994-06||1991-04-23|
|18.104.22.168/8||AfriNIC||2005-04||Formerly IANA - Reserved 1995-05.|
|22.214.171.124/8||APNIC||2010-10||Formerly IANA - Reserved 1995-07.|
|126.96.36.199/8||Administered by APNIC||1991-01||1989-02-21||Originally Japan Inet 1991-01 (IANA Date) or 1989-02-21 (RIR Date). Administered by APNIC not before 2007.|
|188.8.131.52/8||Amateur Radio Digital Communications||1992-07||1992-07-01|
|184.108.40.206/8||Administered by ARIN||1995-01||1991-09-09||Formerly Interop Show Network 1995-01 or 1991-09-09 (RIR Date). Returned to ARIN in 2010-10 except a /15 block. In 2011 it will become available for distribution (or possibly be returned to the IANA, depending on the global policy in effect at that time).|
|220.127.116.11/8||RIPE NCC||2009-09||Formerly Bolt Beranek and Newman Inc. 1992-12. Returned to IANA in 2007-04. Updated to IANA - Reserved in 2007-04.|
|18.104.22.168/8||Bell-Northern Research||1991-01||1989-01-06||Bell-Northern Research, now absorbed into Nortel.|
|22.214.171.124/8||Prudential Securities Inc.||1995-05||1990-12-07||The Prudential Insurance Company of America.|
|126.96.36.199/8||APNIC||2010-08||Formerly Joint Technical Command (Returned to IANA Mar 98) 1994-05. Updated to IANA - Reserved in 2007-05.|
|188.8.131.52/8||ARIN||2010-02||Formerly Joint Technical Command (Returned to IANA Mar 98) 1994-05. Updated to IANA - Reserved in 2007-05.|
|184.108.40.206/8||UK Government Department for Work and Pensions||1994-08||1991-09-16|
|220.127.116.11/8||E.I. duPont de Nemours and Co., Inc.||1991-12||1991-12-19|
|18.104.22.168/8||Cap Debis CCS||1993-10||1992-03-17||Cap Debis CCS (Daimler AG).|
|22.214.171.124/8||Merck and Co., Inc.||1992-03||1992-03-17||Merck has given back the top of this network sometime near January 2012; they now have 54.0-207.*|
|126.96.36.199/8||DoD Network Information Center||1995-04||1996-10-26||Headquarters, USAISC. Formerly Boeing Computer Services 1995-04. Updated to DoD Network Information Center in 2007-02.|
|188.8.131.52/8||US Postal Service||1994-06||1992-11-02|
|127.0.0.0/8||IANA - Loopback||1981-09||127.0.0.0/8 is reserved for Loopback (RFC 5735).|
|184.108.40.206/8||Administered by RIPE||Various Registries (Maintained by RIPE). 220.127.116.11 is the start address of formerly "Class B".|
|18.104.22.168/8||Administered by ARIN||1993-05||1993-05-01||Various Registries (Maintained by ARIN). 169.254.0.0/16 (169.254.0.0–169.254.255.255) reserved for link-local addressing (RFC 5735).|
|22.214.171.124/8||Administered by ARIN||1993-05||1993-05-01||Various Registries (Maintained by ARIN). 172.16.0.0/12 (172.16.0.0–172.31.255.255) reserved for private networks (RFC 1918).|
|192.0.0.0/8||Administered by ARIN||1993-05||1993-05-01||Various Registries (Maintained by ARIN). 192.0.2.0/24 reserved for TEST-NET-1 (RFC 5737). 126.96.36.199/24 reserved for 6to4 Relay Anycast (RFC 3068). 192.168.0.0/16 (192.168.0.0–192.168.255.255) reserved for private networks (RFC 1918). 192.0.0.0/24 reserved for IANA IPv4 Special Purpose Address Registry (RFC 5736). 192.0.0.0 is the start address of formerly "Class C".|
|188.8.131.52/8||Administered by ARIN||1993-05||Various Registries (Maintained by ARIN). 198.18.0.0/15 reserved for Network Interconnect Device Benchmark Testing (RFC 5735). 198.51.100.0/24 reserved for TEST-NET-2 (RFC 5737).|
|184.108.40.206/8||APNIC||1993-05||203.0.113.0/24 reserved for TEST-NET-3 (RFC 5737).|
|220.127.116.11/8||US-DOD||1998-03||1998-03-27||DoD Network Information Center (DNIC).|
|18.104.22.168/8||US-DOD||1998-03||1998-06-05||DoD Network Information Center (DNIC).|
|22.214.171.124/8–126.96.36.199/8||Multicast||1981-09||1991-05-22||Multicast (formerly "Class D") (RFC 5771) registered in . 188.8.131.52/4.|
|240.0.0.0/8–255.0.0.0/8||Future Use||1981-09||Reserved for future use (formerly "Class E") (RFC 1112). 255.255.255.255 is reserved for "limited broadcast" destination address (RFC 919) and (RFC 922). 240.0.0.0/4.|
See also 
- "Public Data Network Numbers". Internet Assigned Numbers Authority. 24 June 2010. Retrieved 27 March 2011.
- "Network 24 - Cable Block". Internet Assigned Numbers Authority. 11 May 2001. Retrieved 27 March 2011.
- "IPv4 IANA Free Pool Depletion – FAQ". American Registry for Internet Numbers. Retrieved 27 March 2011.
- van Beijnum, Iljitsch (September 2007). IPv4 Address Space: 2.46 Billion Down, 1.25 Billion to Go 10 (3). Retrieved 27 March 2011.
- "IANA IPv4 Address Space Registry". Internet Assigned Numbers Authority (IANA). 3 February 2011. Retrieved 27 March 2011. The authoritative up-to-date list of IANA assignments.
- "ARIN Whois Database". American Registry for Internet Numbers (ARIN). Retrieved 27 March 2011.
- Historical IP address lists:
- "INTERNET PROTOCOL ADDRESS SPACE". Internet Assigned Numbers Authority (IANA). October 2000. Archived from the original on 18 October 2000. Retrieved 27 March 2011. First version of IANA table with historical notes via the Internet Archive Wayback Machine.
- "Internet Protocol v4 Address Space". Internet Assigned Numbers Authority (IANA). September 2007. Archived from the original on 28 October 2007. Retrieved 27 March 2011. Last version of IANA table with historical notes via the Internet Archive Wayback Machine.
- Turtschi, Adrian (13 September 1999). "Complete List of Class A and Class B Networks". Adrian Turtschi. Retrieved 27 March 2011.
- Rogers, Paul (November 1999). "IP INDEX Encyclopedia". flumps.org. Archived from the original on 14 April 2001. Retrieved 27 March 2011.
- "IPv4 Addresses - the Complete Class A List". Infocellar. 5 April 2003. Retrieved 27 March 2011.
- "INTERNET PROTOCOL V4 ADDRESS SPACE". DonkBoy Internet. 30 June 2005. Retrieved 27 March 2011.
- Cromwell, Bob (13 November 2008). "The /8 or Class A Networks". Bob Cromwell. Retrieved 27 March 2011.
- Huston, Geoff (29 August 2005). "Report on the IANA IPv4 Address Registry". The Internet Society. Retrieved 27 March 2011.
- Huston, Geoff (July 2003). "IANA IPv4 Address Registry - Current Issues". CIDR Report. Retrieved 27 March 2011.
- "Global Policy for the Allocation of the Remaining IPv4 Address Space". Internet Corporation for Assigned Names and Numbers (ICANN). 6 March 2009. Retrieved 27 March 2011.