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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.154.53.0/24 | 256 | ARIN |  US | 13th Apr 1992 |
| 192.154.56.0/24 | 256 | ARIN | US | 30th Jan 1993 |
| 192.154.57.0/24 | 256 | ARIN | US | 13th Apr 1992 |
| 192.154.68.0/24 | 256 | ARIN | US | 25th Jan 1993 |
| 192.154.69.0/24 | 256 | ARIN | US | 25th Jan 1993 |
| 192.154.70.0/24 | 256 | ARIN | US | 25th Jan 1993 |
| 192.154.71.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.154.72.0/24 | 256 | ARIN | US | 28th Jun 1993 |
| 192.154.74.0/24 | 256 | ARIN | US | 17th Mar 1993 |
| 192.154.75.0/24 | 256 | ARIN | US | 23rd Feb 1993 |
| 192.154.78.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.154.79.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.154.8.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.154.81.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.154.82.0/23 | 512 | ARIN | US | 30th Jul 1993 |
| 192.154.84.0/22 | 1k | ARIN | US | 30th Jul 1993 |
| 192.154.88.0/23 | 512 | ARIN | US | 30th Jul 1993 |
| 192.154.9.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.154.90.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.154.91.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.154.92.0/24 | 256 | ARIN | US | 31st Mar 1993 |
| 192.154.93.0/24 | 256 | ARIN | US | 30th Jul 1993 |
| 192.155.1.0/24 | 256 | RIPE NCC |  NO | 6th Apr 1992 |
| 192.155.10.0/23 | 512 | ARIN | US | 9th Apr 1992 |
| 192.155.12.0/22 | 1k | ARIN | US | 9th Apr 1992 |
| 192.155.128.0/20 | 4.1k | ARIN | US | 20th Apr 1992 |
| 192.155.144.0/21 | 2k | ARIN | US | 20th Apr 1992 |
| 192.155.152.0/22 | 1k | ARIN | US | 20th Apr 1992 |
| 192.155.156.0/23 | 512 | ARIN | US | 20th Apr 1992 |
| 192.155.16.0/20 | 4.1k | ARIN | US | 9th Apr 1992 |
| 192.155.192.0/18 | 16.4k | ARIN | US | 16th Jan 2013 |
| 192.155.2.0/24 | 256 | RIPE NCC | NO | 6th Apr 1992 |
| 192.155.3.0/24 | 256 | RIPE NCC | NO | 6th Apr 1992 |
| 192.155.32.0/19 | 8.2k | ARIN | US | 9th Apr 1992 |
| 192.155.4.0/24 | 256 | RIPE NCC | NO | 6th Apr 1992 |
| 192.155.5.0/24 | 256 | RIPE NCC | NO | 6th Apr 1992 |
| 192.155.6.0/24 | 256 | RIPE NCC | NO | 6th Apr 1992 |
| 192.155.64.0/22 | 1k | ARIN | US | 9th Apr 1992 |
| 192.155.68.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.155.8.0/24 | 256 | ARIN | US | 8th Jul 2015 |
| 192.155.9.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.156.103.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.104.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.105.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.107.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.108.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.112.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.113.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.115.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.116.0/24 | 256 | ARIN | US | 15th Apr 1992 |