Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
Browse by registry
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,430 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 144.149.0.0/16 | 65.5k | ARIN |  US | 13th Dec 1990 |
| 144.150.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.151.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.152.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.153.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.154.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.155.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.156.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.157.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.158.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.159.0.0/16 | 65.5k | ARIN | US | 13th Dec 1990 |
| 144.184.0.0/16 | 65.5k | ARIN | US | 20th Dec 1990 |
| 144.187.0.0/16 | 65.5k | ARIN | US | 20th Dec 1990 |
| 144.189.0.0/16 | 65.5k | ARIN | US | 20th Dec 1990 |
| 144.197.0.0/16 | 65.5k | ARIN | US | 20th Dec 1990 |
| 144.201.0.0/16 | 65.5k | ARIN | US | 20th Dec 1990 |
| 144.208.109.0/24 | 256 | ARIN | US | 23rd Jul 2018 |
| 144.208.90.0/24 | 256 | ARIN | US | 13th Feb 2020 |
| 144.210.0.0/16 | 65.5k | ARIN | US | 15th Jan 1991 |
| 144.215.0.0/16 | 65.5k | ARIN | US | 15th Jan 1991 |
| 144.219.0.0/16 | 65.5k | ARIN | US | 11th Jan 1991 |
| 144.220.0.0/16 | 65.5k | ARIN | US | 27th Apr 2018 |
| 144.221.0.0/16 | 65.5k | ARIN | US | 11th Jan 1991 |
| 144.222.0.0/16 | 65.5k | ARIN | US | 11th Jan 1991 |
| 144.227.0.0/16 | 65.5k | ARIN | US | 6th Jan 1994 |
| 144.231.0.0/16 | 65.5k | ARIN | US | 11th Jan 1991 |
| 144.247.0.0/16 | 65.5k | ARIN | US | 11th Jan 1990 |
| 144.28.0.0/16 | 65.5k | ARIN | US | 9th Nov 1990 |
| 144.34.16.0/21 | 2k | ARIN | US | 16th May 2024 |
| 144.34.24.0/21 | 2k | ARIN | US | 9th Nov 1990 |
| 144.34.40.0/21 | 2k | ARIN | US | 16th May 2024 |
| 144.34.88.0/21 | 2k | ARIN | US | 16th May 2024 |
| 144.36.105.0/24 | 256 | ARIN | US | 9th Nov 1990 |
| 144.36.106.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.132.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.142.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.152.0/21 | 2k | ARIN | US | 9th Nov 1990 |
| 144.36.177.0/24 | 256 | ARIN | US | 9th Nov 1990 |
| 144.36.179.0/24 | 256 | ARIN | US | 9th Nov 1990 |
| 144.36.180.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.186.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.190.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.204.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.208.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.212.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.218.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.240.0/22 | 1k | ARIN | US | 9th Nov 1990 |
| 144.36.246.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.64.0/22 | 1k | ARIN | US | 9th Nov 1990 |
| 144.36.68.0/23 | 512 | ARIN | US | 9th Nov 1990 |