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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 RIPE NCC, largest first.
Unannounced blocks in United States
591 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 13.168.0.0/13 | 524k | RIPE NCC |  US | 25th Apr 1986 |
| 13.176.0.0/13 | 524k | RIPE NCC | US | 25th Apr 1986 |
| 130.195.198.0/24 | 256 | RIPE NCC | US | 26th Sept 1988 |
| 130.78.176.0/24 | 256 | RIPE NCC | US | 24th Jun 1988 |
| 130.78.178.0/23 | 512 | RIPE NCC | US | 24th Jun 1988 |
| 130.78.180.0/22 | 1k | RIPE NCC | US | 24th Jun 1988 |
| 131.222.136.0/21 | 2k | RIPE NCC | US | 6th Apr 1990 |
| 131.222.144.0/20 | 4.1k | RIPE NCC | US | 6th Apr 1990 |
| 135.132.160.0/20 | 4.1k | RIPE NCC | US | 6th Jan 1994 |
| 135.132.32.0/20 | 4.1k | RIPE NCC | US | 6th Jan 1994 |
| 135.137.0.0/16 | 65.5k | RIPE NCC | US | 6th Jan 1994 |
| 136.242.128.0/17 | 32.8k | RIPE NCC | US | 5th Oct 1989 |
| 138.12.128.0/17 | 32.8k | RIPE NCC | US | 10th Jan 1990 |
| 139.100.100.0/22 | 1k | RIPE NCC | US | 15th Feb 1990 |
| 139.100.112.0/20 | 4.1k | RIPE NCC | US | 15th Feb 1990 |
| 139.100.99.0/24 | 256 | RIPE NCC | US | 15th Feb 1990 |
| 144.2.192.0/19 | 8.2k | RIPE NCC | US | 1st Sept 1993 |
| 144.249.0.0/17 | 32.8k | RIPE NCC | US | 11th Jan 1991 |
| 146.162.0.0/19 | 8.2k | RIPE NCC | US | 15th Feb 1991 |
| 146.19.181.0/24 | 256 | RIPE NCC | US | 17th Nov 2021 |
| 146.19.252.0/24 | 256 | RIPE NCC | US | 22nd Nov 2021 |
| 146.255.184.0/24 | 256 | RIPE NCC | US | 30th Aug 2021 |
| 153.15.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |
| 153.58.0.0/16 | 65.5k | RIPE NCC | US | 23rd Sept 1991 |
| 153.63.0.0/16 | 65.5k | RIPE NCC | US | 23rd Sept 1991 |
| 157.70.0.0/17 | 32.8k | RIPE NCC | US | 2nd Oct 1992 |
| 158.120.79.0/24 | 256 | RIPE NCC | US | 28th Feb 1992 |
| 158.178.0.0/17 | 32.8k | RIPE NCC | US | 24th Mar 1992 |
| 158.94.214.0/24 | 256 | RIPE NCC | US | 20th Feb 1992 |
| 159.200.128.0/18 | 16.4k | RIPE NCC | US | 1st Sept 1993 |
| 159.200.201.0/24 | 256 | RIPE NCC | US | 1st Sept 1993 |
| 161.108.209.0/24 | 256 | RIPE NCC | US | 25th Jun 1992 |
| 163.120.128.0/17 | 32.8k | RIPE NCC | US | 20th Jul 1992 |
| 163.79.128.0/17 | 32.8k | RIPE NCC | US | 1st Apr 2005 |
| 164.12.0.0/16 | 65.5k | RIPE NCC | US | 2nd Nov 1992 |
| 164.177.184.0/21 | 2k | RIPE NCC | US | 21st Nov 2011 |
| 166.10.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |
| 166.11.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |
| 166.8.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |
| 166.9.0.0/16 | 65.5k | RIPE NCC | US | 1st Sept 1993 |
| 168.151.21.0/24 | 256 | RIPE NCC | US | 4th Apr 1994 |
| 170.100.147.0/24 | 256 | RIPE NCC | US | 24th Mar 1994 |
| 171.22.200.0/22 | 1k | RIPE NCC | US | 1st Feb 2019 |
| 176.10.89.0/24 | 256 | RIPE NCC | US | 23rd Jan 2025 |
| 176.117.111.0/24 | 256 | RIPE NCC | US | 24th Jul 2025 |
| 176.126.97.0/24 | 256 | RIPE NCC | US | 27th Jan 2026 |
| 176.223.181.0/24 | 256 | RIPE NCC | US | 29th Nov 2011 |
| 178.249.104.0/21 | 2k | RIPE NCC | US | 25th May 2010 |
| 178.255.244.0/22 | 1k | RIPE NCC | US | 15th Jul 2010 |
| 178.79.192.0/18 | 16.4k | RIPE NCC | US | 12th May 2010 |