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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,315 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.4.221.0/24 | 256 | ARIN |  US | 13th Dec 1993 |
| 199.4.222.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.224.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.226.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.228.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.230.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.232.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.234.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.24.0/22 | 1k | ARIN | US | 24th Sept 1993 |
| 199.4.241.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.242.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.244.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.245.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.248.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.252.0/24 | 256 | ARIN | US | 14th Dec 1993 |
| 199.4.253.0/24 | 256 | ARIN | US | 14th Dec 1993 |
| 199.4.254.0/24 | 256 | ARIN | US | 14th Dec 1993 |
| 199.4.8.0/21 | 2k | ARIN | US | 14th Sept 1993 |
| 199.43.104.0/22 | 1k | ARIN | US | 2nd Feb 1994 |
| 199.43.16.0/23 | 512 | ARIN | US | 2nd Feb 1994 |
| 199.43.188.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.43.192.0/23 | 512 | ARIN | US | 1st Mar 1994 |
| 199.43.194.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.43.20.0/22 | 1k | ARIN | US | 2nd Feb 1994 |
| 199.43.208.0/20 | 4.1k | ARIN | US | 16th Dec 1993 |
| 199.43.226.0/23 | 512 | ARIN | US | 7th Dec 1993 |
| 199.43.228.0/22 | 1k | ARIN | US | 7th Dec 1993 |
| 199.43.232.0/22 | 1k | ARIN | US | 7th Dec 1993 |
| 199.43.236.0/23 | 512 | ARIN | US | 7th Dec 1993 |
| 199.43.238.0/23 | 512 | ARIN | US | 7th Dec 1993 |
| 199.43.24.0/21 | 2k | ARIN | US | 2nd Feb 1994 |
| 199.43.240.0/23 | 512 | ARIN | US | 7th Dec 1993 |
| 199.43.242.0/24 | 256 | ARIN | US | 7th Dec 1993 |
| 199.43.32.0/21 | 2k | ARIN | US | 2nd Feb 1994 |
| 199.43.40.0/22 | 1k | ARIN | US | 2nd Feb 1994 |
| 199.43.46.0/23 | 512 | ARIN | US | 2nd Feb 1994 |
| 199.43.62.0/24 | 256 | ARIN | US | 2nd Feb 1994 |
| 199.43.96.0/21 | 2k | ARIN | US | 2nd Feb 1994 |
| 199.45.0.0/21 | 2k | ARIN | US | 5th Nov 1993 |
| 199.45.8.0/22 | 1k | ARIN | US | 5th Nov 1993 |
| 199.46.64.0/19 | 8.2k | ARIN | US | 14th Mar 1994 |
| 199.47.1.0/24 | 256 | ARIN | US | 8th Nov 1993 |
| 199.47.12.0/23 | 512 | ARIN | US | 8th Nov 1993 |
| 199.47.132.0/22 | 1k | ARIN | US | 6th Oct 2010 |
| 199.47.14.0/24 | 256 | ARIN | US | 8th Nov 1993 |
| 199.47.2.0/24 | 256 | ARIN | US | 8th Nov 1993 |
| 199.47.212.0/22 | 1k | ARIN | US | 15th Oct 2010 |
| 199.47.216.0/22 | 1k | ARIN | US | 15th Oct 2010 |
| 199.47.3.0/24 | 256 | ARIN | US | 8th Nov 1993 |
| 199.47.39.0/24 | 256 | ARIN | US | 9th Sept 2015 |