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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.102.184.0/24 | 256 | ARIN |  US | 11th Apr 1991 |
| 192.102.185.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.186.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.187.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.194.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.195.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.197.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.199.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.2.0/24 | 256 | ARIN | US | 8th Mar 1991 |
| 192.102.20.0/22 | 1k | RIPE NCC |  FI | 8th Mar 1991 |
| 192.102.204.0/22 | 1k | APNIC |  CN | 11th Apr 1991 |
| 192.102.208.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.210.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.211.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.212.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.213.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.215.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.216.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.217.0/24 | 256 | ARIN | US | 19th Aug 2026 |
| 192.102.219.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.226.0/24 | 256 | ARIN | US | 11th Apr 1991 |
| 192.102.227.0/24 | 256 | RIPE NCC |  GB | 11th Apr 1991 |
| 192.102.228.0/24 | 256 | RIPE NCC | GB | 11th Apr 1991 |
| 192.102.231.0/24 | 256 | ARIN | US | 12th Apr 1991 |
| 192.102.233.0/24 | 256 | ARIN | US | 12th Apr 1991 |
| 192.102.234.0/24 | 256 | ARIN | US | 12th Apr 1991 |
| 192.102.235.0/24 | 256 | ARIN | US | 28th Jun 2023 |
| 192.102.236.0/24 | 256 | ARIN | US | 16th Apr 1991 |
| 192.102.237.0/24 | 256 | ARIN | US | 16th Apr 1991 |
| 192.102.238.0/24 | 256 | ARIN | US | 16th Apr 1991 |
| 192.102.24.0/21 | 2k | RIPE NCC | FI | 8th Mar 1991 |
| 192.102.240.0/24 | 256 | ARIN | US | 22nd Jan 1996 |
| 192.102.241.0/24 | 256 | ARIN | US | 5th May 1992 |
| 192.102.243.0/24 | 256 | ARIN | US | 24th Apr 1991 |
| 192.102.244.0/22 | 1k | ARIN | US | 24th Apr 1991 |
| 192.102.249.0/24 | 256 | ARIN | US | 24th Apr 1991 |
| 192.102.253.0/24 | 256 | ARIN | US | 5th Jun 2017 |
| 192.102.3.0/24 | 256 | ARIN | US | 8th Mar 1991 |
| 192.102.4.0/24 | 256 | ARIN | US | 8th Mar 1991 |
| 192.102.64.0/23 | 512 | RIPE NCC | FI | 8th Mar 1991 |
| 192.102.66.0/23 | 512 | RIPE NCC | FI | 8th Mar 1991 |
| 192.102.68.0/22 | 1k | RIPE NCC | FI | 8th Mar 1991 |
| 192.102.72.0/21 | 2k | RIPE NCC | FI | 8th Mar 1991 |
| 192.102.8.0/24 | 256 | RIPE NCC | GB | 8th Mar 1991 |
| 192.102.80.0/23 | 512 | RIPE NCC | FI | 8th Mar 1991 |
| 192.102.82.0/24 | 256 | ARIN |  VI | 13th Mar 1991 |
| 192.102.84.0/24 | 256 | LACNIC |  PE | 13th Mar 1991 |
| 192.102.89.0/24 | 256 | RIPE NCC |  DE | 13th Mar 1991 |
| 192.102.90.0/24 | 256 | ARIN | US | 13th Mar 1991 |
| 192.102.91.0/24 | 256 | ARIN | US | 4th Apr 1991 |