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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.146.245.0/24 | 256 | ARIN |  US | 8th Feb 1992 |
| 192.146.246.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.146.247.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.146.248.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.146.249.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.146.250.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.146.252.0/24 | 256 | APNIC |  AU | 8th Feb 1992 |
| 192.146.253.0/24 | 256 | APNIC | AU | 8th Feb 1992 |
| 192.146.64.0/19 | 8.2k | ARIN | US | 14th May 1992 |
| 192.146.96.0/22 | 1k | ARIN | US | 14th May 1992 |
| 192.147.0.0/23 | 512 | ARIN | US | 10th Feb 2015 |
| 192.147.10.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.100.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.101.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.102.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.103.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.104.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.105.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.106.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.107.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.108.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.109.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.11.0/24 | 256 | ARIN | US | 30th Mar 2018 |
| 192.147.110.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.111.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.112.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.147.117.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.13.0/24 | 256 | ARIN | US | 4th Dec 1995 |
| 192.147.136.0/22 | 1k | ARIN | US | 12th May 1992 |
| 192.147.14.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.140.0/24 | 256 | ARIN | US | 12th May 1992 |
| 192.147.141.0/24 | 256 | RIPE NCC |  PL | 15th Feb 1992 |
| 192.147.146.0/24 | 256 | ARIN | US | 15th Feb 1992 |
| 192.147.147.0/24 | 256 | ARIN | US | 15th Feb 1992 |
| 192.147.148.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 192.147.15.0/24 | 256 | ARIN | US | 8th Feb 1992 |
| 192.147.150.0/24 | 256 | RIPE NCC |  GB | 15th Feb 1992 |
| 192.147.154.0/24 | 256 | ARIN | US | 15th Feb 1992 |
| 192.147.156.0/24 | 256 | ARIN | US | 15th Feb 1992 |
| 192.147.157.0/24 | 256 | ARIN | US | 14th Jan 1996 |
| 192.147.158.0/24 | 256 | ARIN | US | 15th Feb 1992 |
| 192.147.159.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.169.0/24 | 256 | ARIN | US | 23rd Jun 1993 |
| 192.147.171.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.180.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.181.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.182.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.183.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.184.0/24 | 256 | ARIN | US | 16th Feb 1992 |
| 192.147.185.0/24 | 256 | ARIN | US | 16th Feb 1992 |