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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 registered through ARIN
30,456 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.251.92.0/24 | 256 | ARIN |  US | 25th Nov 1992 |
| 192.251.96.0/24 | 256 | ARIN | US | 27th Nov 1992 |
| 192.251.98.0/24 | 256 | ARIN | US | 27th Nov 1992 |
| 192.252.16.0/20 | 4.1k | ARIN | US | 6th Nov 1992 |
| 192.252.240.0/20 | 4.1k | ARIN | US | 14th Jul 2022 |
| 192.252.32.0/19 | 8.2k | ARIN | US | 12th Nov 1992 |
| 192.254.32.0/19 | 8.2k | ARIN | US | 20th Nov 1992 |
| 192.26.1.0/24 | 256 | ARIN | US | 9th Sept 1986 |
| 192.26.100.0/24 | 256 | ARIN | US | 23rd Dec 1986 |
| 192.26.101.0/24 | 256 | ARIN | US | 23rd Dec 1986 |
| 192.26.102.0/24 | 256 | ARIN | US | 23rd Dec 1986 |
| 192.26.138.0/23 | 512 | ARIN | US | 25th Jul 2017 |
| 192.26.147.0/24 | 256 | ARIN | US | 26th Feb 1987 |
| 192.26.148.0/24 | 256 | ARIN | US | 26th Feb 1987 |
| 192.26.151.0/24 | 256 | ARIN | US | 26th Feb 1987 |
| 192.26.152.0/24 | 256 | ARIN | US | 9th Jul 1993 |
| 192.26.153.0/24 | 256 | ARIN | US | 24th Apr 1990 |
| 192.26.2.0/24 | 256 | ARIN | US | 9th Sept 1986 |
| 192.26.201.0/24 | 256 | ARIN | US | 13th Mar 1989 |
| 192.26.202.0/23 | 512 | ARIN | US | 13th Mar 1989 |
| 192.26.204.0/22 | 1k | ARIN | US | 13th Mar 1989 |
| 192.26.208.0/23 | 512 | ARIN | US | 13th Mar 1989 |
| 192.26.211.0/24 | 256 | ARIN |  CA | 4th Nov 1990 |
| 192.26.213.0/24 | 256 | ARIN | US | 30th May 1990 |
| 192.26.22.0/24 | 256 | ARIN | US | 28th Apr 2023 |
| 192.26.23.0/24 | 256 | ARIN | US | 28th Apr 2023 |
| 192.26.24.0/24 | 256 | ARIN | US | 28th Apr 2023 |
| 192.26.248.0/24 | 256 | ARIN | US | 20th Mar 1989 |
| 192.26.255.0/24 | 256 | ARIN | US | 4th Apr 2014 |
| 192.26.3.0/24 | 256 | ARIN | US | 9th Sept 1986 |
| 192.26.4.0/24 | 256 | ARIN | US | 9th Sept 1986 |
| 192.26.48.0/24 | 256 | ARIN | US | 12th Feb 1988 |
| 192.26.49.0/24 | 256 | ARIN | US | 19th Apr 1989 |
| 192.26.5.0/24 | 256 | ARIN | US | 9th Sept 1986 |
| 192.26.6.0/24 | 256 | ARIN | US | 9th Sept 1986 |
| 192.26.8.0/24 | 256 | ARIN | US | 20th Oct 1986 |
| 192.26.82.0/24 | 256 | ARIN | US | 17th Dec 1986 |
| 192.26.83.0/24 | 256 | ARIN | US | 23rd Dec 1986 |
| 192.26.88.0/24 | 256 | ARIN | US | 7th Jan 1987 |
| 192.26.90.0/24 | 256 | ARIN | US | 28th Jan 1987 |
| 192.26.95.0/24 | 256 | ARIN | US | 19th Feb 1987 |
| 192.26.97.0/24 | 256 | ARIN | US | 26th Feb 1987 |
| 192.28.100.0/22 | 1k | ARIN | US | 16th Feb 1988 |
| 192.28.104.0/22 | 1k | ARIN | US | 16th Feb 1988 |
| 192.28.108.0/23 | 512 | ARIN | US | 16th Feb 1988 |
| 192.28.110.0/23 | 512 | ARIN | US | 16th Feb 1988 |
| 192.28.112.0/21 | 2k | ARIN | US | 16th Feb 1988 |
| 192.28.132.0/22 | 1k | ARIN | US | 16th Feb 1988 |
| 192.28.136.0/22 | 1k | ARIN | US | 16th Feb 1988 |
| 192.28.140.0/22 | 1k | ARIN | US | 16th Feb 1988 |