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)[1], or a regional Internet registry.
Each /8 block contains 16777216 addresses.
As IPv4 address exhaustion has advanced to its final stages, some organizations, such as Stanford University, formerly using 36.0.0.0/8, have returned their allocated block to assist in the delay of the exhaustion date.
List of assigned /8 blocks
| Block | Organization |
|---|---|
| 0.0.0.0/8 | IANA (Internet Assigned Numbers Authority) Local Identification |
| 3.0.0.0/8 | General Electric |
| 4.0.0.0/8 | Level 3 Communications (originally BBN, then GTE, then Genuity) |
| 6.0.0.0/8 | United States Department of Defense USAISC |
| 7.0.0.0/8 | United States Department of Defense Network Information Center |
| 8.0.0.0/8 | Level 3 Communications (originally BBN) |
| 9.0.0.0/8 | IBM |
| 10.0.0.0/8 | reserved for RFC1918 usage |
| 11.0.0.0/8 | United States Department of Defense Network Information Center |
| 12.0.0.0/8 | AT&T Worldnet Services |
| 13.0.0.0/8 | Xerox Palo Alto Research Center |
| 15.0.0.0/8 | Hewlett-Packard |
| 16.0.0.0/8 | Hewlett-Packard (originally DEC, then Compaq) |
| 17.0.0.0/8 | Apple Inc. |
| 18.0.0.0/8 | Massachusetts Institute of Technology |
| 19.0.0.0/8 | Ford Motor Company |
| 20.0.0.0/8 | Computer Sciences Corporation |
| 21.0.0.0/8 | United States Department of Defense Network Information Center |
| 22.0.0.0/8 | United States Department of Defense Network Information Center |
| 24.0.0.0/8 | Various U.S. and Canadian Cable Networks |
| 25.0.0.0/8 | British Ministry of Defence |
| 26.0.0.0/8 | United States Department of Defense Network Information Center |
| 28.0.0.0/8 | United States Department of Defense Network Information Center |
| 29.0.0.0/8 | United States Department of Defense Network Information Center |
| 30.0.0.0/8 | United States Department of Defense Network Information Center |
| 32.0.0.0/8 | AT&T Global Network Services |
| 33.0.0.0/8 | United States Department of Defense Network Information Center |
| 34.0.0.0/8 | Halliburton Company |
| 35.0.0.0/8 | Merit Network, Inc. |
| 38.0.0.0/8 | Cogent Communications (originally Performance Systems International) |
| 40.0.0.0/8 | Eli Lilly and Company |
| 44.0.0.0/8 | Amateur Radio Digital Communications |
| 45.0.0.0/8 | Interop Show Network (all but a /15 to be returned to ARIN pool per 10/2010 announcement) |
| 47.0.0.0/8 | Bell-Northern Research (now a unit of Nortel) |
| 48.0.0.0/8 | The Prudential Insurance Company of America |
| 51.0.0.0/8 | UK Department for Work and Pensions |
| 52.0.0.0/8 | E.I. DuPont de Nemours and Co., Inc. |
| 53.0.0.0/8 | Cap debis ccs (Daimler AG) |
| 54.0.0.0/8 | Merck and Co., Inc. |
| 55.0.0.0/8 | United States Department of Defense USAIC |
| 56.0.0.0/8 | United States Postal Service |
| 57.0.0.0/8 | SITA |
Note that this list does not include any assignments of /8 blocks to the regional or national Internet registries.
References
- ^ The authoritative up-to-date list of IANA assignments can be found on this IANA page