So who has the class A network addresses? Well it turns out that many of these have been recovered from their original allocations, and handed back to IANA (Internet Assigned Numbers Authority). Many of these have then been allocated to registries such as the American Registry for Internet Numbers (ARIN), and are being carved up into smaller blocks and allocated out. We will discuss how that works in lecture 3.

But there are still a good number of class A networks allocated to organisations that really don’t need blocks that large (although giving up their blocks would be an expensive process). The list below shows the current allocations of all class A networks on the Internet.

1 IANA – Reserved
2 IANA – Reserved
3 General Electric Company
4 Level3/Genuity-BBN (IANA INFO: Bolt Beranek and Newman Inc.)
5 IANA – Reserved
6 Army Information Systems Center
7 IANA – Reserved
8 Level3/Genuity-BBN (IANA INFO: Bolt Beranek and Newman Inc.)
9 IBM
10 IANA – Private Use. See RFC 1918
11 DoD Intel Information Systems
12 AT&T Bell Laboratories
13 Xerox Corporation
14 IANA – Public Data Network
15 Hewlett-Packard Company
16 Digital Equipment Corporation
17 Apple Computer Inc.
18 MIT
19 Ford Motor Company
20 Computer Sciences Corporation
21 DDN-RVN
22 Defense Information Systems Agency
23 IANA – Reserved
24 ARIN – Cable Block (Formerly IANA – Jul 95)
25 Royal Signals and Radar Establishment
26 Defense Information Systems Agency
27 IANA – Reserved
28 DSI-North
29 Defense Information Systems Agency
30 Defense Information Systems Agency
31 IANA – Reserved
32 AT&T (IANA INFO: Norsk Informasjonsteknologi)
33 DLA Systems Automation Center
34 Halliburton Company
35 MERIT Computer Network
36 IANA – Reserved (Formerly Stanford University – Apr 93 to
37 IANA – Reserved
38 COGENT/PSI (IANA INFO: Performance Systems International)
39 IANA – Reserved
40 Eli Lily and Company
41 AFRINIC
42 IANA – Reserved
43 V6NIC
44 Amateur Radio Digital Communications
45 Interop Show Network
46 Level3/Genuity-BBN (IANA INFO: Bolt Beranek and Newman Inc.)
47 Nortel (IANA INFO: Bell-Northern Research)
48 Prudential Securities Inc.
49 IANA (Formerly DoD – Joint Technical Command. Used: May 94
50 IANA (Formerly DoD – Joint Technical Command. Used: May 94
51 Deparment of Social Security of UK (EU territory should be
52 E.I. duPont de Nemours and Co., Inc.
53 Cap Debis CCS (EU territory should be in RIPE database)
54 Merck and Co., Inc.
55 Naval Ocean Systems Center (IANA INFO: Boeing Computer Services)
56 U.S. Postal Service
57 SITA (Equant.Net routable. EU territory should be in RIPE database)
58 APNIC
59 APNIC
60 APNIC
61 APNIC
62 RIPE
63 ARIN
64 ARIN
65 ARIN
66 ARIN
67 ARIN
68 ARIN
69 ARIN
70 ARIN
71 ARIN
72 ARIN
73 ARIN
74 ARIN
75 ARIN
76 ARIN
77 IANA – Reserved
78 IANA – Reserved
79 IANA – Reserved
80 RIPE
81 RIPE
82 RIPE
83 RIPE
84 RIPE
85 RIPE
86 RIPE
87 RIPE
88 RIPE
89 RIPE
90 RIPE
91 RIPE
92 IANA – Reserved
93 IANA – Reserved
94 IANA – Reserved
95 IANA – Reserved
96 IANA – Reserved
97 IANA – Reserved
98 IANA – Reserved
99 IANA – Reserved
100 IANA – Reserved
101 IANA – Reserved
102 IANA – Reserved
103 IANA – Reserved
104 IANA – Reserved
105 IANA – Reserved
106 IANA – Reserved
107 IANA – Reserved
108 IANA – Reserved
109 IANA – Reserved
110 IANA – Reserved
111 IANA – Reserved
112 IANA – Reserved
113 IANA – Reserved
114 IANA – Reserved
115 IANA – Reserved
116 IANA – Reserved
117 IANA – Reserved
118 IANA – Reserved
119 IANA – Reserved
120 IANA – Reserved
121 IANA – Reserved
122 IANA – Reserved
123 IANA – Reserved
124 APNIC
125 APNIC
126 APNIC