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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
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 |
|---|---|---|---|---|
| 144.36.74.0/23 | 512 | ARIN |  US | 9th Nov 1990 |
| 144.36.76.0/22 | 1k | ARIN | US | 9th Nov 1990 |
| 144.36.80.0/20 | 4.1k | ARIN | US | 9th Nov 1990 |
| 144.36.96.0/21 | 2k | ARIN | US | 9th Nov 1990 |
| 144.5.0.0/16 | 65.5k | ARIN | US | 30th Oct 1990 |
| 144.61.0.0/16 | 65.5k | ARIN | US | 13th Nov 1990 |
| 144.67.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.68.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.70.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.72.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.8.0.0/16 | 65.5k | ARIN | US | 31st Oct 1990 |
| 144.86.152.0/22 | 1k | ARIN | US | 11th May 2020 |
| 144.86.226.0/23 | 512 | ARIN | US | 20th Nov 1990 |
| 144.86.239.0/24 | 256 | ARIN | US | 20th Nov 2020 |
| 144.86.240.0/22 | 1k | ARIN | US | 20th Nov 1990 |
| 144.86.244.0/23 | 512 | ARIN | US | 20th Nov 1990 |
| 144.86.248.0/23 | 512 | ARIN | US | 20th Nov 1990 |
| 144.86.251.0/24 | 256 | ARIN | US | 20th Nov 1990 |
| 144.86.252.0/22 | 1k | ARIN | US | 20th Nov 1990 |
| 144.89.96.0/19 | 8.2k | ARIN | US | 20th Nov 1990 |
| 144.90.0.0/16 | 65.5k | ARIN | US | 16th Jun 2026 |
| 146.10.0.0/16 | 65.5k | ARIN | US | 17th Jan 1991 |
| 146.123.0.0/16 | 65.5k | ARIN | US | 9th Nov 2023 |
| 146.125.0.0/16 | 65.5k | ARIN | US | 7th Feb 1991 |
| 146.128.0.0/16 | 65.5k | ARIN | US | 8th Feb 1991 |
| 146.13.0.0/16 | 65.5k | ARIN | US | 17th Jan 1991 |
| 146.135.128.0/17 | 32.8k | ARIN | US | 8th Feb 1991 |
| 146.147.0.0/16 | 65.5k | ARIN | US | 24th Nov 2015 |
| 146.149.0.0/16 | 65.5k | ARIN | US | 15th Feb 1991 |
| 146.150.0.0/16 | 65.5k | ARIN | US | 15th Feb 1991 |
| 146.156.0.0/16 | 65.5k | ARIN | US | 15th Feb 1991 |
| 146.170.0.0/16 | 65.5k | ARIN | US | 22nd Feb 1991 |
| 146.180.0.0/16 | 65.5k | ARIN | US | 26th Feb 1991 |
| 146.204.0.0/15 | 131k | ARIN | US | 28th Feb 1991 |
| 146.208.0.0/16 | 65.5k | ARIN | US | 2nd Dec 1994 |
| 146.223.0.0/16 | 65.5k | ARIN | US | 24th Aug 1994 |
| 146.237.0.0/16 | 65.5k | ARIN | US | 5th Mar 1991 |
| 146.238.0.0/16 | 65.5k | ARIN | US | 5th Mar 1991 |
| 146.239.0.0/16 | 65.5k | ARIN | US | 5th Mar 1991 |
| 146.24.0.0/13 | 524k | ARIN | US | 18th Jan 1991 |
| 146.252.0.0/16 | 65.5k | ARIN | US | 6th Mar 1991 |
| 146.32.0.0/13 | 524k | ARIN | US | 18th Jan 1991 |
| 146.40.0.0/14 | 262k | ARIN | US | 18th Jan 1991 |
| 146.44.0.0/15 | 131k | ARIN | US | 18th Jan 1991 |
| 146.46.0.0/16 | 65.5k | ARIN | US | 18th Jan 1991 |
| 146.47.0.0/16 | 65.5k | ARIN | US | 18th Jan 1991 |
| 146.61.0.0/16 | 65.5k | ARIN | US | 21st Jan 1991 |
| 146.69.0.0/16 | 65.5k | ARIN | US | 23rd Jan 1991 |
| 146.71.128.0/17 | 32.8k | ARIN | US | 23rd Jan 1991 |
| 146.73.0.0/16 | 65.5k | ARIN | US | 23rd Jan 1991 |