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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,310 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.74.235.0/24 | 256 | ARIN |  US | 2nd Jul 2025 |
| 199.74.238.0/23 | 512 | ARIN | US | 28th Jan 1994 |
| 199.74.240.0/23 | 512 | ARIN | US | 28th Jan 1994 |
| 199.74.242.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.243.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.245.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.246.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.247.0/24 | 256 | ARIN | US | 1st Jan 1994 |
| 199.74.248.0/24 | 256 | ARIN | US | 1st Jan 1994 |
| 199.74.250.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.251.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.252.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.74.253.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.128.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.129.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.131.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.132.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.133.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.134.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.135.0/24 | 256 | ARIN | US | 31st Jan 1994 |
| 199.79.136.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.137.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.138.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.139.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.140.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.141.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.142.0/23 | 512 | ARIN | US | 1st Feb 1994 |
| 199.79.144.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.145.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.150.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.151.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.153.0/24 | 256 | ARIN | US | 1st Feb 1994 |
| 199.79.154.0/24 | 256 | ARIN | US | 28th Aug 2017 |
| 199.79.157.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.79.158.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.79.159.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.79.160.0/23 | 512 | ARIN | US | 2nd Feb 1994 |
| 199.79.162.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.79.163.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.79.164.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.79.173.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.174.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.175.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.181.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.182.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.183.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.186.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.187.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.188.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.189.0/24 | 256 | ARIN | US | 7th Feb 1994 |