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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.107.24.0/23 | 512 | ARIN |  US | 30th Apr 1991 |
| 192.107.240.0/24 | 256 | ARIN | US | 4th Jun 1991 |
| 192.107.244.0/24 | 256 | ARIN | US | 26th Jun 2024 |
| 192.107.248.0/22 | 1k | ARIN | US | 4th Jun 1991 |
| 192.107.252.0/24 | 256 | ARIN | US | 4th Jun 1991 |
| 192.107.253.0/24 | 256 | ARIN | US | 4th Jun 1991 |
| 192.107.254.0/24 | 256 | ARIN | US | 4th Jun 1991 |
| 192.107.26.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.27.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.3.0/24 | 256 | ARIN | US | 24th Apr 1991 |
| 192.107.32.0/23 | 512 | ARIN | US | 30th Apr 1991 |
| 192.107.34.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.35.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.36.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.37.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.4.0/24 | 256 | RIPE NCC |  GB | 26th Apr 1991 |
| 192.107.40.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.42.0/24 | 256 | ARIN | US | 2nd May 1991 |
| 192.107.48.0/24 | 256 | ARIN | US | 3rd May 1991 |
| 192.107.49.0/24 | 256 | ARIN | US | 2nd Jul 2025 |
| 192.107.5.0/24 | 256 | RIPE NCC | GB | 26th Apr 1991 |
| 192.107.6.0/24 | 256 | ARIN | US | 13th Jan 2026 |
| 192.107.7.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.107.8.0/24 | 256 | ARIN | US | 30th Apr 1991 |
| 192.108.1.0/24 | 256 | ARIN | US | 26th Apr 1991 |
| 192.108.102.0/24 | 256 | ARIN | US | 7th Mar 1996 |
| 192.108.103.0/24 | 256 | ARIN | US | 10th May 1991 |
| 192.108.107.0/24 | 256 | RIPE NCC |  SE | 22nd Jul 1991 |
| 192.108.108.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1991 |
| 192.108.109.0/24 | 256 | ARIN | US | 22nd Jul 1991 |
| 192.108.110.0/24 | 256 | ARIN | US | 22nd Jul 1991 |
| 192.108.111.0/24 | 256 | ARIN | US | 22nd Jul 1991 |
| 192.108.112.0/24 | 256 | ARIN | US | 22nd Jul 1991 |
| 192.108.121.0/24 | 256 | RIPE NCC |  AT | 24th Jul 1991 |
| 192.108.122.0/24 | 256 | ARIN | US | 24th Jul 1991 |
| 192.108.123.0/24 | 256 | ARIN | US | 13th Sept 1996 |
| 192.108.127.0/24 | 256 | ARIN | US | 12th Mar 2015 |
| 192.108.128.0/24 | 256 | RIPE NCC |  CZ | 12th Jan 1993 |
| 192.108.129.0/24 | 256 | RIPE NCC | CZ | 28th Sept 1992 |
| 192.108.134.0/23 | 512 | RIPE NCC |  SK | 24th Jul 1991 |
| 192.108.160.0/21 | 2k | RIPE NCC | SK | 24th Jul 1991 |
| 192.108.168.0/22 | 1k | RIPE NCC | SK | 24th Jul 1991 |
| 192.108.17.0/24 | 256 | ARIN | US | 29th Apr 1991 |
| 192.108.174.0/24 | 256 | RIPE NCC | SK | 24th Jul 1991 |
| 192.108.18.0/24 | 256 | ARIN | US | 29th Apr 1991 |
| 192.108.186.0/24 | 256 | ARIN | US | 24th Jul 1991 |
| 192.108.187.0/24 | 256 | ARIN | US | 24th Jul 1991 |
| 192.108.189.0/24 | 256 | ARIN | US | 24th Jul 1991 |
| 192.108.192.0/23 | 512 | ARIN | US | 24th Jul 1991 |
| 192.108.194.0/24 | 256 | ARIN | US | 24th Jul 1991 |