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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.102.93.0/24 | 256 | ARIN |  US | 4th Apr 1991 |
| 192.102.94.0/24 | 256 | ARIN | US | 4th Apr 1991 |
| 192.103.0.0/24 | 256 | ARIN | US | 12th Mar 2015 |
| 192.103.1.0/24 | 256 | ARIN | US | 15th Apr 1991 |
| 192.103.10.0/24 | 256 | ARIN | US | 20th Jun 1991 |
| 192.103.127.0/24 | 256 | ARIN | US | 31st Jul 1991 |
| 192.103.128.0/24 | 256 | ARIN | US | 31st Jul 1991 |
| 192.103.129.0/24 | 256 | ARIN | US | 31st Jul 1991 |
| 192.103.13.0/24 | 256 | ARIN | US | 28th Jun 1991 |
| 192.103.134.0/24 | 256 | ARIN | US | 9th Aug 1991 |
| 192.103.135.0/24 | 256 | ARIN | US | 12th Aug 1991 |
| 192.103.137.0/24 | 256 | RIPE NCC |  GB | 12th Aug 1991 |
| 192.103.138.0/23 | 512 | RIPE NCC | GB | 12th Aug 1991 |
| 192.103.14.0/24 | 256 | RIPE NCC |  AE | 1st Jul 1991 |
| 192.103.140.0/24 | 256 | ARIN | US | 12th Aug 1991 |
| 192.103.141.0/24 | 256 | ARIN | US | 12th Aug 1991 |
| 192.103.142.0/24 | 256 | ARIN | US | 13th Aug 1991 |
| 192.103.143.0/24 | 256 | ARIN | US | 13th Aug 1991 |
| 192.103.145.0/24 | 256 | ARIN | US | 13th Aug 1991 |
| 192.103.146.0/24 | 256 | ARIN | US | 14th Aug 1991 |
| 192.103.147.0/24 | 256 | RIPE NCC |  PT | 14th Aug 1991 |
| 192.103.15.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.103.16.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.103.17.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.103.18.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.103.19.0/24 | 256 | ARIN | US | 1st Jul 1991 |
| 192.103.22.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 192.103.23.0/24 | 256 | RIPE NCC |  DE | 5th Jul 1991 |
| 192.103.240.0/21 | 2k | ARIN | US | 14th Aug 1991 |
| 192.103.25.0/24 | 256 | ARIN | US | 5th Jul 1991 |
| 192.103.250.0/24 | 256 | ARIN | US | 15th Jan 2015 |
| 192.103.253.0/24 | 256 | ARIN | US | 23rd Sept 2022 |
| 192.103.27.0/24 | 256 | RIPE NCC | DE | 5th Jul 1991 |
| 192.103.28.0/22 | 1k | RIPE NCC | GB | 8th Jul 1991 |
| 192.103.3.0/24 | 256 | ARIN | US | 29th Apr 1991 |
| 192.103.32.0/21 | 2k | RIPE NCC | GB | 8th Jul 1991 |
| 192.103.40.0/24 | 256 | RIPE NCC | DE | 8th Jul 1991 |
| 192.103.47.0/24 | 256 | ARIN | US | 11th Jul 1991 |
| 192.103.48.0/24 | 256 | ARIN | US | 11th Jul 1991 |
| 192.103.49.0/24 | 256 | ARIN | US | 12th Jul 1991 |
| 192.103.5.0/24 | 256 | ARIN | US | 27th Jan 1995 |
| 192.103.54.0/24 | 256 | ARIN | US | 11th Jul 1991 |
| 192.103.55.0/24 | 256 | ARIN | US | 11th Jul 1991 |
| 192.103.57.0/24 | 256 | ARIN | US | 11th Jul 1991 |
| 192.103.58.0/24 | 256 | ARIN | US | 11th Jul 1991 |
| 192.103.59.0/24 | 256 | ARIN | US | 12th Jul 1991 |
| 192.103.6.0/24 | 256 | ARIN | US | 20th Jun 1991 |
| 192.103.60.0/22 | 1k | ARIN | US | 12th Jul 1991 |
| 192.103.7.0/24 | 256 | RIPE NCC |  FR | 20th Jun 1991 |
| 192.103.79.0/24 | 256 | ARIN | US | 12th Jul 1991 |