IANA IPv4 Address Space Registry

Last Updated
2014-03-19
Registration Procedure(s)
Allocations to RIRs are made in line with the Global Policy published at [http://www.icann.org/en/resources/policy/global-addressing]. 
All other assignments require IETF Review.
Description
The allocation of Internet Protocol version 4 (IPv4) address space to various registries is listed
here. Originally, all the IPv4 address spaces was managed directly by the IANA. Later parts of the
address space were allocated to various other registries to manage for particular purposes or
regional areas of the world. RFC 1466 [RFC1466] documents most of these allocations.
Reference
[RFC-housley-number-registries-04]
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Prefix Designation Date Whois Status [1] Note
000/8 IANA - Local Identification 1981-09 RESERVED [2]
001/8 APNIC 2010-01 whois.apnic.net ALLOCATED
002/8 RIPE NCC 2009-09 whois.ripe.net ALLOCATED
003/8 General Electric Company 1994-05 whois.arin.net LEGACY
004/8 Level 3 Communications, Inc. 1992-12 whois.arin.net LEGACY
005/8 RIPE NCC 2010-11 whois.ripe.net ALLOCATED
006/8 Army Information Systems Center 1994-02 LEGACY
007/8 Administered by ARIN 1995-04 whois.arin.net LEGACY
008/8 Level 3 Communications, Inc. 1992-12 whois.arin.net LEGACY
009/8 IBM 1992-08 whois.arin.net LEGACY
010/8 IANA - Private Use 1995-06 RESERVED [3]
011/8 DoD Intel Information Systems 1993-05 LEGACY
012/8 AT&T Bell Laboratories 1995-06 whois.arin.net LEGACY
013/8 Xerox Corporation 1991-09 whois.arin.net LEGACY
014/8 APNIC 2010-04 whois.apnic.net ALLOCATED [4]
015/8 Hewlett-Packard Company 1994-07 whois.arin.net LEGACY
016/8 Digital Equipment Corporation 1994-11 whois.arin.net LEGACY
017/8 Apple Computer Inc. 1992-07 whois.arin.net LEGACY
018/8 MIT 1994-01 whois.arin.net LEGACY
019/8 Ford Motor Company 1995-05 whois.arin.net LEGACY
020/8 Computer Sciences Corporation 1994-10 whois.arin.net LEGACY
021/8 DDN-RVN 1991-07 LEGACY
022/8 Defense Information Systems Agency 1993-05 LEGACY
023/8 ARIN 2010-11 whois.arin.net ALLOCATED
024/8 ARIN 2001-05 whois.arin.net ALLOCATED
025/8 UK Ministry of Defence 1995-01 whois.ripe.net LEGACY
026/8 Defense Information Systems Agency 1995-05 LEGACY
027/8 APNIC 2010-01 whois.apnic.net ALLOCATED
028/8 DSI-North 1992-07 LEGACY
029/8 Defense Information Systems Agency 1991-07 LEGACY
030/8 Defense Information Systems Agency 1991-07 LEGACY
031/8 RIPE NCC 2010-05 whois.ripe.net ALLOCATED
032/8 AT&T Global Network Services 1994-06 whois.arin.net LEGACY
033/8 DLA Systems Automation Center 1991-01 LEGACY
034/8 Halliburton Company 1993-03 whois.arin.net LEGACY
035/8 Administered by ARIN 1994-04 whois.arin.net LEGACY
036/8 APNIC 2010-10 whois.apnic.net ALLOCATED
037/8 RIPE NCC 2010-11 whois.ripe.net ALLOCATED
038/8 PSINet, Inc. 1994-09 whois.arin.net LEGACY
039/8 APNIC 2011-01 whois.apnic.net ALLOCATED
040/8 Administered by ARIN 1994-06 whois.arin.net LEGACY
041/8 AFRINIC 2005-04 whois.afrinic.net ALLOCATED
042/8 APNIC 2010-10 whois.apnic.net ALLOCATED
043/8 Administered by APNIC 1991-01 whois.apnic.net LEGACY
044/8 Amateur Radio Digital Communications 1992-07 whois.arin.net LEGACY
045/8 Administered by ARIN 1995-01 whois.arin.net LEGACY
046/8 RIPE NCC 2009-09 whois.ripe.net ALLOCATED
047/8 Administered by ARIN 1991-01 whois.arin.net LEGACY
048/8 Prudential Securities Inc. 1995-05 whois.arin.net LEGACY
049/8 APNIC 2010-08 whois.apnic.net ALLOCATED
050/8 ARIN 2010-02 whois.arin.net ALLOCATED
051/8 UK Government Department for Work and Pensions 1994-08 whois.ripe.net LEGACY
052/8 E.I. duPont de Nemours and Co., Inc. 1991-12 whois.arin.net LEGACY
053/8 Cap Debis CCS 1993-10 LEGACY
054/8 Administered by ARIN 1992-03 whois.arin.net LEGACY
055/8 DoD Network Information Center 1995-04 LEGACY
056/8 US Postal Service 1994-06 whois.arin.net LEGACY
057/8 SITA 1995-05 LEGACY
058/8 APNIC 2004-04 whois.apnic.net ALLOCATED
059/8 APNIC 2004-04 whois.apnic.net ALLOCATED
060/8 APNIC 2003-04 whois.apnic.net ALLOCATED
061/8 APNIC 1997-04 whois.apnic.net ALLOCATED
062/8 RIPE NCC 1997-04 whois.ripe.net ALLOCATED
063/8 ARIN 1997-04 whois.arin.net ALLOCATED
064/8 ARIN 1999-07 whois.arin.net ALLOCATED
065/8 ARIN 2000-07 whois.arin.net ALLOCATED
066/8 ARIN 2000-07 whois.arin.net ALLOCATED
067/8 ARIN 2001-05 whois.arin.net ALLOCATED
068/8 ARIN 2001-06 whois.arin.net ALLOCATED
069/8 ARIN 2002-08 whois.arin.net ALLOCATED
070/8 ARIN 2004-01 whois.arin.net ALLOCATED
071/8 ARIN 2004-08 whois.arin.net ALLOCATED
072/8 ARIN 2004-08 whois.arin.net ALLOCATED
073/8 ARIN 2005-03 whois.arin.net ALLOCATED
074/8 ARIN 2005-06 whois.arin.net ALLOCATED
075/8 ARIN 2005-06 whois.arin.net ALLOCATED
076/8 ARIN 2005-06 whois.arin.net ALLOCATED
077/8 RIPE NCC 2006-08 whois.ripe.net ALLOCATED
078/8 RIPE NCC 2006-08 whois.ripe.net ALLOCATED
079/8 RIPE NCC 2006-08 whois.ripe.net ALLOCATED
080/8 RIPE NCC 2001-04 whois.ripe.net ALLOCATED
081/8 RIPE NCC 2001-04 whois.ripe.net ALLOCATED
082/8 RIPE NCC 2002-11 whois.ripe.net ALLOCATED
083/8 RIPE NCC 2003-11 whois.ripe.net ALLOCATED
084/8 RIPE NCC 2003-11 whois.ripe.net ALLOCATED
085/8 RIPE NCC 2004-04 whois.ripe.net ALLOCATED
086/8 RIPE NCC 2004-04 whois.ripe.net ALLOCATED
087/8 RIPE NCC 2004-04 whois.ripe.net ALLOCATED
088/8 RIPE NCC 2004-04 whois.ripe.net ALLOCATED
089/8 RIPE NCC 2005-06 whois.ripe.net ALLOCATED
090/8 RIPE NCC 2005-06 whois.ripe.net ALLOCATED
091/8 RIPE NCC 2005-06 whois.ripe.net ALLOCATED
092/8 RIPE NCC 2007-03 whois.ripe.net ALLOCATED
093/8 RIPE NCC 2007-03 whois.ripe.net ALLOCATED
094/8 RIPE NCC 2007-07 whois.ripe.net ALLOCATED
095/8 RIPE NCC 2007-07 whois.ripe.net ALLOCATED
096/8 ARIN 2006-10 whois.arin.net ALLOCATED
097/8 ARIN 2006-10 whois.arin.net ALLOCATED
098/8 ARIN 2006-10 whois.arin.net ALLOCATED
099/8 ARIN 2006-10 whois.arin.net ALLOCATED
100/8 ARIN 2010-11 whois.arin.net ALLOCATED [5]
101/8 APNIC 2010-08 whois.apnic.net ALLOCATED
102/8 AFRINIC 2011-02 whois.afrinic.net ALLOCATED
103/8 APNIC 2011-02 whois.apnic.net ALLOCATED
104/8 ARIN 2011-02 whois.arin.net ALLOCATED
105/8 AFRINIC 2010-11 whois.afrinic.net ALLOCATED
106/8 APNIC 2011-01 whois.apnic.net ALLOCATED
107/8 ARIN 2010-02 whois.arin.net ALLOCATED
108/8 ARIN 2008-12 whois.arin.net ALLOCATED
109/8 RIPE NCC 2009-01 whois.ripe.net ALLOCATED
110/8 APNIC 2008-11 whois.apnic.net ALLOCATED
111/8 APNIC 2008-11 whois.apnic.net ALLOCATED
112/8 APNIC 2008-05 whois.apnic.net ALLOCATED
113/8 APNIC 2008-05 whois.apnic.net ALLOCATED
114/8 APNIC 2007-10 whois.apnic.net ALLOCATED
115/8 APNIC 2007-10 whois.apnic.net ALLOCATED
116/8 APNIC 2007-01 whois.apnic.net ALLOCATED
117/8 APNIC 2007-01 whois.apnic.net ALLOCATED
118/8 APNIC 2007-01 whois.apnic.net ALLOCATED
119/8 APNIC 2007-01 whois.apnic.net ALLOCATED
120/8 APNIC 2007-01 whois.apnic.net ALLOCATED
121/8 APNIC 2006-01 whois.apnic.net ALLOCATED
122/8 APNIC 2006-01 whois.apnic.net ALLOCATED
123/8 APNIC 2006-01 whois.apnic.net ALLOCATED
124/8 APNIC 2005-01 whois.apnic.net ALLOCATED
125/8 APNIC 2005-01 whois.apnic.net ALLOCATED
126/8 APNIC 2005-01 whois.apnic.net ALLOCATED
127/8 IANA - Loopback 1981-09 RESERVED [6]
128/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
129/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
130/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
131/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
132/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
133/8 Administered by APNIC 1997-03 whois.apnic.net LEGACY
134/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
135/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
136/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
137/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
138/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
139/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
140/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
141/8 Administered by RIPE NCC 1993-05 whois.ripe.net LEGACY
142/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
143/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
144/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
145/8 Administered by RIPE NCC 1993-05 whois.ripe.net LEGACY
146/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
147/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
148/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
149/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
150/8 Administered by APNIC 1993-05 whois.apnic.net LEGACY
151/8 Administered by RIPE NCC 1993-05 whois.ripe.net LEGACY
152/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
153/8 Administered by APNIC 1993-05 whois.apnic.net LEGACY
154/8 Administered by AFRINIC 1993-05 whois.afrinic.net LEGACY
155/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
156/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
157/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
158/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
159/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
160/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
161/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
162/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
163/8 Administered by APNIC 1993-05 whois.apnic.net LEGACY
164/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
165/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
166/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
167/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
168/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
169/8 Administered by ARIN 1993-05 whois.arin.net LEGACY [7]
170/8 Administered by ARIN 1993-05 whois.arin.net LEGACY
171/8 Administered by APNIC 1993-05 whois.apnic.net LEGACY
172/8 Administered by ARIN 1993-05 whois.arin.net LEGACY [8]
173/8 ARIN 2008-02 whois.arin.net ALLOCATED
174/8 ARIN 2008-02 whois.arin.net ALLOCATED
175/8 APNIC 2009-08 whois.apnic.net ALLOCATED
176/8 RIPE NCC 2010-05 whois.ripe.net ALLOCATED
177/8 LACNIC 2010-06 whois.lacnic.net ALLOCATED
178/8 RIPE NCC 2009-01 whois.ripe.net ALLOCATED
179/8 LACNIC 2011-02 whois.lacnic.net ALLOCATED
180/8 APNIC 2009-04 whois.apnic.net ALLOCATED
181/8 LACNIC 2010-06 whois.lacnic.net ALLOCATED
182/8 APNIC 2009-08 whois.apnic.net ALLOCATED
183/8 APNIC 2009-04 whois.apnic.net ALLOCATED
184/8 ARIN 2008-12 whois.arin.net ALLOCATED
185/8 RIPE NCC 2011-02 whois.ripe.net ALLOCATED
186/8 LACNIC 2007-09 whois.lacnic.net ALLOCATED
187/8 LACNIC 2007-09 whois.lacnic.net ALLOCATED
188/8 Administered by RIPE NCC 1993-05 whois.ripe.net LEGACY
189/8 LACNIC 1995-06 whois.lacnic.net ALLOCATED
190/8 LACNIC 1995-06 whois.lacnic.net ALLOCATED
191/8 Administered by LACNIC 1993-05 whois.lacnic.net LEGACY
192/8 Administered by ARIN 1993-05 whois.arin.net LEGACY [9][10]
193/8 RIPE NCC 1993-05 whois.ripe.net ALLOCATED
194/8 RIPE NCC 1993-05 whois.ripe.net ALLOCATED
195/8 RIPE NCC 1993-05 whois.ripe.net ALLOCATED
196/8 Administered by AFRINIC 1993-05 whois.afrinic.net LEGACY
197/8 AFRINIC 2008-10 whois.afrinic.net ALLOCATED
198/8 Administered by ARIN 1993-05 whois.arin.net LEGACY [11]
199/8 ARIN 1993-05 whois.arin.net ALLOCATED
200/8 LACNIC 2002-11 whois.lacnic.net ALLOCATED
201/8 LACNIC 2003-04 whois.lacnic.net ALLOCATED
202/8 APNIC 1993-05 whois.apnic.net ALLOCATED
203/8 APNIC 1993-05 whois.apnic.net ALLOCATED [12]
204/8 ARIN 1994-03 whois.arin.net ALLOCATED
205/8 ARIN 1994-03 whois.arin.net ALLOCATED
206/8 ARIN 1995-04 whois.arin.net ALLOCATED
207/8 ARIN 1995-11 whois.arin.net ALLOCATED
208/8 ARIN 1996-04 whois.arin.net ALLOCATED
209/8 ARIN 1996-06 whois.arin.net ALLOCATED
210/8 APNIC 1996-06 whois.apnic.net ALLOCATED
211/8 APNIC 1996-06 whois.apnic.net ALLOCATED
212/8 RIPE NCC 1997-10 whois.ripe.net ALLOCATED
213/8 RIPE NCC 1993-10 whois.ripe.net ALLOCATED
214/8 US-DOD 1998-03 LEGACY
215/8 US-DOD 1998-03 LEGACY
216/8 ARIN 1998-04 whois.arin.net ALLOCATED
217/8 RIPE NCC 2000-06 whois.ripe.net ALLOCATED
218/8 APNIC 2000-12 whois.apnic.net ALLOCATED
219/8 APNIC 2001-09 whois.apnic.net ALLOCATED
220/8 APNIC 2001-12 whois.apnic.net ALLOCATED
221/8 APNIC 2002-07 whois.apnic.net ALLOCATED
222/8 APNIC 2003-02 whois.apnic.net ALLOCATED
223/8 APNIC 2010-04 whois.apnic.net ALLOCATED
224/8 Multicast 1981-09 RESERVED [13]
225/8 Multicast 1981-09 RESERVED [13]
226/8 Multicast 1981-09 RESERVED [13]
227/8 Multicast 1981-09 RESERVED [13]
228/8 Multicast 1981-09 RESERVED [13]
229/8 Multicast 1981-09 RESERVED [13]
230/8 Multicast 1981-09 RESERVED [13]
231/8 Multicast 1981-09 RESERVED [13]
232/8 Multicast 1981-09 RESERVED [13]
233/8 Multicast 1981-09 RESERVED [13]
234/8 Multicast 1981-09 RESERVED [13][14]
235/8 Multicast 1981-09 RESERVED [13]
236/8 Multicast 1981-09 RESERVED [13]
237/8 Multicast 1981-09 RESERVED [13]
238/8 Multicast 1981-09 RESERVED [13]
239/8 Multicast 1981-09 RESERVED [13][15]
240/8 Future use 1981-09 RESERVED [16]
241/8 Future use 1981-09 RESERVED [16]
242/8 Future use 1981-09 RESERVED [16]
243/8 Future use 1981-09 RESERVED [16]
244/8 Future use 1981-09 RESERVED [16]
245/8 Future use 1981-09 RESERVED [16]
246/8 Future use 1981-09 RESERVED [16]
247/8 Future use 1981-09 RESERVED [16]
248/8 Future use 1981-09 RESERVED [16]
249/8 Future use 1981-09 RESERVED [16]
250/8 Future use 1981-09 RESERVED [16]
251/8 Future use 1981-09 RESERVED [16]
252/8 Future use 1981-09 RESERVED [16]
253/8 Future use 1981-09 RESERVED [16]
254/8 Future use 1981-09 RESERVED [16]
255/8 Future use 1981-09 RESERVED [16][17]

Footnotes

[1]
Indicates the status of address blocks as follows:
RESERVED: designated by the IETF for specific non-global-unicast purposes as noted.
LEGACY: allocated by the central Internet Registry (IR) prior to the Regional Internet Registries
(RIRs). This address space is now administered by individual RIRs as noted, including maintenance
of WHOIS Directory and reverse DNS records. Assignments from these blocks are distributed globally
on a regional basis.
ALLOCATED: delegated entirely to specific RIR as indicated.
UNALLOCATED: not yet allocated or reserved.
[2]
0.0.0.0/8 reserved for self-identification [RFC1122], section 3.2.1.3. 
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv4-special-registry].
[3]
Reserved for Private-Use Networks [RFC1918].
Complete registration details for 10.0.0.0/8 are found in [IANA registry iana-ipv4-special-registry].
[4]
This was reserved for Public Data Networks [RFC1356]. See [IANA registry public-data-network-numbers].
It was recovered in February 2008 and was subsequently allocated to APNIC in April 2010.
[5]
100.64.0.0/10 reserved for Shared Address Space [RFC6598]. 
Complete registration details for 100.64.0.0/10 are found in [IANA registry iana-ipv4-special-registry].
[6]
127.0.0.0/8 reserved for Loopback [RFC1122], section 3.2.1.3. 
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv4-special-registry].
[7]
169.254.0.0/16 reserved for Link Local [RFC3927].
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv4-special-registry].
[8]
172.16.0.0/12 reserved for Private-Use Networks [RFC1918]. 
Complete registration details are found in [IANA registry iana-ipv4-special-registry].
[9]
192.0.2.0/24  reserved for TEST-NET-1 [RFC5737]. 
Complete registration details for 192.0.2.0/24 are found in [IANA registry iana-ipv4-special-registry].
192.88.99.0/24 reserved for 6to4 Relay Anycast [RFC3068]
Complete registration details for 192.88.99.0/24 are found in [IANA registry iana-ipv4-special-registry].
192.88.99.2/32 reserved for 6a44 Relay Anycast [RFC6751] (possibly collocated with 6to4 Relay 
at 192.88.99.1/32 - see [RFC3068] section 2.4)
192.168.0.0/16 reserved for Private-Use Networks [RFC1918]. 
Complete registration details for 192.168.0.0/16 are found in [IANA registry iana-ipv4-special-registry].
[10]
192.0.0.0/24 reserved for IANA IPv4 Special Purpose Address Registry [RFC5736]. 
Complete registration details for 192.0.0.0/24 are found in [IANA registry iana-ipv4-special-registry].
[11]
198.18.0.0/15 reserved for Network Interconnect Device Benchmark Testing [RFC2544]. 
Complete registration details for 198.18.0.0/15 are found in [IANA registry iana-ipv4-special-registry].
198.51.100.0/24 reserved for TEST-NET-2 [RFC5737]. 
Complete registration details for 198.51.100.0/24 are found in [IANA registry iana-ipv4-special-registry].
[12]
203.0.113.0/24 reserved for TEST-NET-3 [RFC5737]. 
Complete registration details for 203.0.113.0/24 are found in [IANA registry iana-ipv4-special-registry].
[13]
Multicast (formerly "Class D") [RFC5771] registered in [IANA registry multicast-addresses]
[14]
Unicast-Prefix-Based IPv4 Multicast Addresses [RFC6034]
[15]
Administratively Scoped IP Multicast [RFC2365]
[16]
Reserved for future use (formerly "Class E") [RFC1112].
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv4-special-registry].
[17]
255.255.255.255 is reserved for "limited broadcast" destination address [RFC919] and [RFC922].
Complete registration details for 255.255.255.255/32 are found in [IANA registry iana-ipv4-special-registry].