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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks
85,392 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.80.96.0/22 | 1k | ARIN |  US | 6th Dec 1994 |
| 204.86.0.0/21 | 2k | ARIN | US | 7th Sept 1994 |
| 204.86.104.0/21 | 2k | ARIN | US | 23rd Nov 1994 |
| 204.86.112.0/22 | 1k | ARIN | US | 23rd Nov 1994 |
| 204.86.12.0/24 | 256 | ARIN | US | 7th Sept 1994 |
| 204.86.120.0/21 | 2k | ARIN | US | 1st Dec 1994 |
| 204.86.128.0/23 | 512 | ARIN | US | 1st Dec 1994 |
| 204.86.130.0/23 | 512 | ARIN | US | 8th Mar 2023 |
| 204.86.152.0/21 | 2k | ARIN | US | 7th Dec 1994 |
| 204.86.16.0/20 | 4.1k | ARIN | US | 26th Jul 1994 |
| 204.86.160.0/21 | 2k | ARIN | US | 7th Dec 1994 |
| 204.86.194.0/24 | 256 | ARIN | US | 16th Oct 2024 |
| 204.86.196.0/22 | 1k | ARIN | US | 2nd Jan 2009 |
| 204.86.208.0/21 | 2k | ARIN | US | 16th Dec 1994 |
| 204.86.224.0/21 | 2k | ARIN | US | 5th May 1995 |
| 204.86.232.0/21 | 2k | ARIN | US | 27th Dec 1994 |
| 204.86.240.0/21 | 2k | ARIN | US | 27th Dec 1994 |
| 204.86.248.0/24 | 256 | ARIN | US | 21st Feb 1995 |
| 204.86.249.0/24 | 256 | ARIN | US | 14th Oct 2011 |
| 204.86.8.0/22 | 1k | ARIN | US | 7th Sept 1994 |
| 204.86.96.0/21 | 2k | ARIN | US | 26th Oct 1994 |
| 204.87.0.0/20 | 4.1k | ARIN | US | 17th Aug 1994 |
| 204.87.128.0/24 | 256 | ARIN | US | 9th Dec 1994 |
| 204.87.129.0/24 | 256 | ARIN |  CA | 9th Dec 1994 |
| 204.87.130.0/24 | 256 | ARIN | US | 9th Dec 1994 |
| 204.87.131.0/24 | 256 | ARIN | US | 14th Dec 1994 |
| 204.87.132.0/24 | 256 | ARIN | US | 16th Dec 1994 |
| 204.87.133.0/24 | 256 | ARIN | US | 16th Dec 1994 |
| 204.87.134.0/24 | 256 | ARIN | US | 16th Dec 1994 |
| 204.87.137.0/24 | 256 | ARIN | US | 27th Dec 1994 |
| 204.87.138.0/24 | 256 | ARIN | US | 27th Dec 1994 |
| 204.87.139.0/24 | 256 | ARIN | US | 27th Dec 1994 |
| 204.87.140.0/24 | 256 | ARIN | US | 27th Dec 1994 |
| 204.87.141.0/24 | 256 | ARIN | US | 27th Dec 1994 |
| 204.87.143.0/24 | 256 | ARIN | US | 27th Dec 1994 |
| 204.87.144.0/24 | 256 | ARIN | US | 28th Dec 1994 |
| 204.87.145.0/24 | 256 | ARIN | US | 28th Dec 1994 |
| 204.87.146.0/24 | 256 | ARIN | US | 28th Dec 1994 |
| 204.87.147.0/24 | 256 | ARIN | US | 28th Dec 1994 |
| 204.87.148.0/24 | 256 | ARIN | US | 28th Dec 1994 |
| 204.87.150.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.152.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.153.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.154.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.156.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.159.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.161.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.162.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.163.0/24 | 256 | ARIN | US | 29th Dec 1994 |
| 204.87.164.0/24 | 256 | ARIN | US | 29th Dec 1994 |