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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,427 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 135.25.0.0/16 | 65.5k | ARIN |  US | 30th Apr 1996 |
| 135.252.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.27.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.30.0.0/16 | 65.5k | ARIN | US | 14th May 1997 |
| 135.31.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.32.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.34.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.36.0.0/16 | 65.5k | ARIN | US | 13th Apr 1989 |
| 135.37.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.38.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.48.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.52.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.53.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.54.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.55.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.57.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.58.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.59.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.61.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.62.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.63.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.64.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.65.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.66.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.68.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.72.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.75.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.76.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.80.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 135.84.116.0/22 | 1k | ARIN | US | 15th Jun 2016 |
| 135.84.123.0/24 | 256 | ARIN | US | 4th May 2016 |
| 135.84.16.0/20 | 4.1k | ARIN |  CA | 23rd Jul 2018 |
| 135.84.35.0/24 | 256 | ARIN | US | 12th Apr 2016 |
| 135.84.4.0/23 | 512 | ARIN | US | 13th Apr 1989 |
| 135.84.88.0/23 | 512 | ARIN | US | 28th Nov 2016 |
| 135.84.98.0/23 | 512 | ARIN | US | 23rd Apr 2020 |
| 135.89.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.91.0.0/16 | 65.5k | ARIN | US | 30th Apr 1996 |
| 135.94.0.0/15 | 131k | ARIN | US | 30th Apr 1996 |
| 135.96.0.0/14 | 262k | ARIN | US | 30th Apr 1996 |
| 136.104.0.0/15 | 131k | ARIN | US | 1st Aug 2024 |
| 136.106.0.0/16 | 65.5k | ARIN | US | 1st Aug 2024 |
| 136.131.0.0/16 | 65.5k | ARIN | US | 22nd Aug 1989 |
| 136.133.0.0/16 | 65.5k | ARIN | US | 22nd Aug 1989 |
| 136.141.0.0/16 | 65.5k | ARIN | US | 24th Aug 1989 |
| 136.143.194.0/24 | 256 | ARIN | US | 8th Jul 2026 |
| 136.143.196.0/23 | 512 | ARIN | US | 12th Aug 2026 |
| 136.151.0.0/16 | 65.5k | ARIN | US | 6th Mar 1991 |
| 136.171.0.0/16 | 65.5k | ARIN | US | 5th Sept 1989 |
| 136.175.105.0/24 | 256 | ARIN | US | 20th Oct 2020 |