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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,273 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 56.224.0.0/16 | 65.5k | ARIN |  US | 2nd Nov 1992 |
| 56.226.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.229.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.230.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.231.0.0/16 | 65.5k | ARIN | US | 14th Mar 2023 |
| 56.237.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.238.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.240.0.0/16 | 65.5k | ARIN | US | 21st Jul 2023 |
| 56.241.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.242.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.243.0.0/16 | 65.5k | ARIN | US | 24th Jun 2022 |
| 56.244.0.0/15 | 131k | ARIN | US | 21st Jul 2023 |
| 56.246.0.0/16 | 65.5k | ARIN | US | 21st Jul 2023 |
| 56.247.0.0/16 | 65.5k | ARIN | US | 25th Nov 2024 |
| 56.251.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.253.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.37.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.42.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.48.0.0/16 | 65.5k | ARIN | US | 24th Jun 2022 |
| 56.49.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.50.0.0/15 | 131k | ARIN | US | 9th Dec 2022 |
| 56.52.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.53.0.0/16 | 65.5k | ARIN | US | 30th Aug 2022 |
| 56.54.0.0/15 | 131k | ARIN | US | 30th Aug 2022 |
| 56.64.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.71.0.0/16 | 65.5k | ARIN | US | 9th Dec 2022 |
| 56.72.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.75.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.76.0.0/15 | 131k | ARIN | US | 2nd Nov 1992 |
| 56.78.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.83.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.88.0.0/16 | 65.5k | ARIN | US | 2nd Nov 1992 |
| 56.94.0.0/15 | 131k | ARIN | US | 2nd Nov 1992 |
| 56.96.0.0/16 | 65.5k | ARIN | US | 24th Jun 2022 |
| 56.97.0.0/16 | 65.5k | ARIN | US | 14th Mar 2023 |
| 56.98.0.0/16 | 65.5k | ARIN | US | 24th Jun 2022 |
| 56.99.0.0/16 | 65.5k | ARIN | US | 14th Mar 2023 |
| 63.132.0.0/16 | 65.5k | ARIN | US | 12th Jun 2002 |
| 63.133.0.0/17 | 32.8k | ARIN | US | 12th Jun 2002 |
| 63.133.212.0/23 | 512 | ARIN | US | 3rd Oct 2023 |
| 63.135.167.0/24 | 256 | ARIN | US | 1st Jun 2020 |
| 63.135.68.0/24 | 256 | ARIN | US | 21st Nov 2003 |
| 63.135.80.0/20 | 4.1k | ARIN | US | 7th Aug 2007 |
| 63.140.16.0/20 | 4.1k | ARIN | US | 10th Dec 2010 |
| 63.141.64.0/18 | 16.4k | ARIN | US | 13th Jan 2011 |
| 63.245.192.0/20 | 4.1k | ARIN | US | 25th Aug 2010 |
| 63.247.112.0/20 | 4.1k | ARIN | US | 9th Apr 2007 |
| 63.251.116.0/24 | 256 | ARIN | US | 2nd Dec 1999 |
| 63.251.118.0/23 | 512 | ARIN | US | 2nd Dec 1999 |
| 63.251.121.0/24 | 256 | ARIN | US | 2nd Dec 1999 |