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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,195 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.52.185.0/24 | 256 | APNIC |  TL | 7th Jan 2026 |
| 192.52.186.0/24 | 256 | ARIN |  US | 3rd May 1989 |
| 192.52.187.0/24 | 256 | ARIN | US | 4th May 1989 |
| 192.52.195.0/24 | 256 | ARIN | US | 8th May 1989 |
| 192.52.196.0/23 | 512 | APNIC |  AU | 24th Feb 2011 |
| 192.52.218.0/24 | 256 | ARIN | US | 10th May 1989 |
| 192.52.221.0/24 | 256 | RIPE NCC |  NL | 10th May 1989 |
| 192.52.222.0/24 | 256 | RIPE NCC | NL | 10th May 1989 |
| 192.52.223.0/24 | 256 | RIPE NCC | NL | 10th May 1989 |
| 192.52.226.0/24 | 256 | ARIN | US | 18th Nov 1993 |
| 192.52.229.0/24 | 256 | ARIN | US | 15th May 1989 |
| 192.52.230.0/24 | 256 | ARIN | US | 15th May 1989 |
| 192.52.231.0/24 | 256 | ARIN | US | 15th May 1989 |
| 192.52.232.0/24 | 256 | AFRINIC |  DZ | 9th Dec 1993 |
| 192.52.239.0/24 | 256 | ARIN |  CA | 17th May 1989 |
| 192.52.244.0/24 | 256 | ARIN | US | 18th May 1989 |
| 192.52.245.0/24 | 256 | ARIN | US | 18th May 1989 |
| 192.52.252.0/24 | 256 | ARIN | US | 24th May 1989 |
| 192.52.253.0/24 | 256 | RIPE NCC |  GB | 24th May 1989 |
| 192.52.254.0/24 | 256 | RIPE NCC |  FR | 24th May 1989 |
| 192.52.51.0/24 | 256 | ARIN | US | 23rd Mar 1989 |
| 192.52.56.0/22 | 1k | ARIN | US | 23rd Mar 1989 |
| 192.52.60.0/24 | 256 | ARIN | US | 23rd Mar 1989 |
| 192.52.66.0/24 | 256 | ARIN | US | 4th Apr 1989 |
| 192.52.67.0/24 | 256 | ARIN | US | 13th Jan 1989 |
| 192.52.68.0/24 | 256 | ARIN | US | 13th Jan 1989 |
| 192.52.69.0/24 | 256 | ARIN | US | 13th Jan 1989 |
| 192.52.71.0/24 | 256 | ARIN | US | 6th Apr 1989 |
| 192.52.76.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.52.77.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.52.79.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.52.93.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.52.96.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.52.97.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.52.99.0/24 | 256 | ARIN | US | 7th Apr 1989 |
| 192.53.0.0/23 | 512 | ARIN | US | 27th Mar 1989 |
| 192.53.100.0/23 | 512 | ARIN | US | 27th Mar 1989 |
| 192.53.102.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.53.105.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.53.106.0/23 | 512 | ARIN | US | 27th Mar 1989 |
| 192.53.108.0/22 | 1k | ARIN | US | 27th Mar 1989 |
| 192.53.128.0/21 | 2k | ARIN | US | 27th Mar 1989 |
| 192.53.144.0/21 | 2k | ARIN | US | 27th Mar 1989 |
| 192.53.152.0/22 | 1k | ARIN | US | 27th Mar 1989 |
| 192.53.156.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.53.157.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.53.158.0/23 | 512 | ARIN | US | 27th Mar 1989 |
| 192.53.16.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.53.17.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.53.176.0/22 | 1k | ARIN | US | 27th Mar 1989 |