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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 ARIN, largest first.
Unannounced blocks registered through ARIN
30,449 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.231.108.0/24 | 256 | ARIN |  US | 2nd Oct 1992 |
| 192.231.11.0/24 | 256 | ARIN | US | 22nd Sept 1992 |
| 192.231.111.0/24 | 256 | ARIN | US | 6th Oct 1992 |
| 192.231.12.0/24 | 256 | ARIN | US | 22nd Sept 1992 |
| 192.231.126.0/24 | 256 | ARIN | US | 6th Oct 1992 |
| 192.231.129.0/24 | 256 | ARIN | US | 7th Oct 1992 |
| 192.231.13.0/24 | 256 | ARIN | US | 22nd Sept 1992 |
| 192.231.138.0/24 | 256 | ARIN | US | 8th Oct 1992 |
| 192.231.139.0/24 | 256 | ARIN | US | 8th Oct 1992 |
| 192.231.14.0/24 | 256 | ARIN | US | 22nd Sept 1992 |
| 192.231.142.0/24 | 256 | ARIN | US | 8th Oct 1992 |
| 192.231.148.0/24 | 256 | ARIN | US | 9th Oct 1992 |
| 192.231.149.0/24 | 256 | ARIN | US | 24th Jul 1996 |
| 192.231.150.0/24 | 256 | ARIN | US | 9th Oct 1992 |
| 192.231.156.0/22 | 1k | ARIN | US | 9th Oct 1992 |
| 192.231.161.0/24 | 256 | ARIN | US | 12th Oct 1992 |
| 192.231.165.0/24 | 256 | ARIN | US | 13th Oct 1992 |
| 192.231.172.0/24 | 256 | ARIN |  CA | 13th Oct 1992 |
| 192.231.173.0/24 | 256 | ARIN | CA | 13th Oct 1992 |
| 192.231.174.0/24 | 256 | ARIN | CA | 13th Oct 1992 |
| 192.231.180.0/24 | 256 | ARIN | US | 13th Oct 1992 |
| 192.231.181.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.182.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.184.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.185.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.186.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.187.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.189.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.190.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.194.0/24 | 256 | ARIN | US | 15th Oct 1992 |
| 192.231.195.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.196.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.197.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.200.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.204.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.205.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.206.0/24 | 256 | ARIN | US | 16th Oct 1992 |
| 192.231.208.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 192.231.209.0/24 | 256 | ARIN | US | 20th Oct 1992 |
| 192.231.210.0/24 | 256 | ARIN | US | 20th Oct 1992 |
| 192.231.217.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.221.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.222.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.223.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.224.0/22 | 1k | ARIN | US | 22nd Oct 1992 |
| 192.231.228.0/23 | 512 | ARIN | US | 22nd Oct 1992 |
| 192.231.232.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.235.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.236.0/24 | 256 | ARIN | US | 22nd Oct 1992 |
| 192.231.239.0/24 | 256 | ARIN | US | 22nd Oct 1992 |