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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in Japan
1,446 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 59.156.202.0/24 | 256 | APNIC |  JP | 18th Nov 2004 |
| 59.156.21.0/24 | 256 | APNIC | JP | 18th Nov 2004 |
| 59.156.22.0/23 | 512 | APNIC | JP | 18th Nov 2004 |
| 59.156.25.0/24 | 256 | APNIC | JP | 18th Nov 2004 |
| 59.156.26.0/23 | 512 | APNIC | JP | 18th Nov 2004 |
| 59.156.28.0/24 | 256 | APNIC | JP | 18th Nov 2004 |
| 59.157.208.0/20 | 4.1k | APNIC | JP | 18th Nov 2004 |
| 60.254.192.0/18 | 16.4k | APNIC | JP | 1st Sept 2006 |
| 61.245.104.0/22 | 1k | APNIC | JP | 21st Jul 2005 |
| 61.245.124.0/22 | 1k | APNIC | JP | 21st Jul 2005 |
| 61.44.0.0/23 | 512 | APNIC | JP | 28th Aug 2003 |
| 61.44.2.0/24 | 256 | APNIC | JP | 28th Aug 2003 |
| 61.44.3.0/24 | 256 | APNIC | JP | 28th Aug 2003 |
| 61.44.4.0/22 | 1k | APNIC | JP | 28th Aug 2003 |
| 61.44.67.0/24 | 256 | APNIC | JP | 26th Sept 2003 |
| 61.44.8.0/21 | 2k | APNIC | JP | 28th Aug 2003 |
| 61.47.0.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.102.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.47.108.0/22 | 1k | APNIC | JP | 1st Mar 2005 |
| 61.47.15.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.17.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.21.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.22.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.24.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.27.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.29.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.3.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.4.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.47.44.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.47.46.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.49.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.50.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.47.53.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.54.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.47.56.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.64.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.47.66.0/24 | 256 | APNIC | JP | 1st Mar 2005 |
| 61.47.72.0/21 | 2k | APNIC | JP | 1st Mar 2005 |
| 61.47.98.0/23 | 512 | APNIC | JP | 1st Mar 2005 |
| 61.5.240.0/23 | 512 | APNIC | JP | 28th Jul 2006 |
| 61.5.244.0/24 | 256 | APNIC | JP | 28th Jul 2006 |
| 61.87.12.0/23 | 512 | APNIC | JP | 26th Sept 2003 |
| 61.87.8.0/22 | 1k | APNIC | JP | 26th Sept 2003 |
| 65.99.63.0/24 | 256 | APNIC | JP | 2nd Aug 2004 |
| 81.203.0.0/16 | 65.5k | APNIC | JP | 12th Nov 2002 |
| 91.243.68.0/24 | 256 | RIPE NCC | JP | 10th Jun 2025 |