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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 199.116.0.0/22 | 1k | ARIN |  US | 24th Jul 1996 |
| 199.116.16.0/20 | 4.1k | ARIN | US | 13th Jan 1994 |
| 199.116.32.0/20 | 4.1k | ARIN | US | 9th Feb 1994 |
| 199.116.4.0/23 | 512 | ARIN | US | 24th Jul 1996 |
| 199.116.48.0/22 | 1k | ARIN | US | 9th Feb 1994 |
| 199.116.64.0/21 | 2k | ARIN | US | 5th Mar 2012 |
| 199.116.84.0/22 | 1k | ARIN | US | 7th Mar 2012 |
| 199.119.16.0/21 | 2k | ARIN | US | 22nd Jan 1994 |
| 199.119.184.0/21 | 2k | ARIN | US | 12th May 2011 |
| 199.119.32.0/19 | 8.2k | ARIN | US | 22nd Jan 1994 |
| 199.120.0.0/21 | 2k | ARIN | US | 24th Jan 1994 |
| 199.120.130.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.120.132.0/22 | 1k | ARIN | US | 1st Mar 1994 |
| 199.120.136.0/23 | 512 | ARIN | US | 1st Mar 1994 |
| 199.120.138.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.120.139.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 199.120.140.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.145.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.146.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 199.120.155.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.156.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.159.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.160.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.161.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.162.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.163.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.164.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.165.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.168.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.169.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.170.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 199.120.175.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.176.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 199.120.178.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.120.179.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.180.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.182.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.183.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.184.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.185.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.186.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.187.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.188.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 199.120.190.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.192.0/23 | 512 | ARIN | US | 4th Mar 1994 |
| 199.120.194.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.195.0/24 | 256 | ARIN | US | 6th May 2021 |
| 199.120.196.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.197.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 199.120.198.0/24 | 256 | ARIN | US | 4th Mar 1994 |