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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through APNIC, largest first.
Unannounced blocks in Japan
1,422 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 150.36.0.0/16 | 65.5k | APNIC |  JP | 31st Mar 1997 |
| 150.4.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.40.0.0/18 | 16.4k | APNIC | JP | 6th Apr 1995 |
| 150.40.64.0/21 | 2k | APNIC | JP | 6th Apr 1995 |
| 150.44.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.45.0.0/16 | 65.5k | APNIC | JP | 23rd Jun 1992 |
| 150.48.192.0/18 | 16.4k | APNIC | JP | 4th Mar 1993 |
| 150.50.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.51.0.0/16 | 65.5k | APNIC | JP | 4th Mar 1993 |
| 150.53.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.58.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.6.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.62.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.64.0.0/16 | 65.5k | APNIC | JP | 2nd Sept 1992 |
| 150.68.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.72.0.0/14 | 262k | APNIC | JP | 3rd Nov 1992 |
| 150.76.0.0/14 | 262k | APNIC | JP | 23rd Mar 1993 |
| 150.8.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.80.0.0/16 | 65.5k | APNIC | JP | 1st Apr 1992 |
| 150.81.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.85.0.0/16 | 65.5k | APNIC | JP | 26th Apr 1994 |
| 150.88.0.0/16 | 65.5k | APNIC | JP | 10th Feb 1992 |
| 150.92.0.0/16 | 65.5k | APNIC | JP | 22nd May 1996 |
| 150.94.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.95.0.0/23 | 512 | APNIC | JP | 31st Mar 1997 |
| 150.95.2.0/23 | 512 | APNIC | JP | 31st Mar 1997 |
| 150.95.4.0/22 | 1k | APNIC | JP | 31st Mar 1997 |
| 150.98.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 151.158.222.0/23 | 512 | APNIC | JP | 24th Feb 2026 |
| 153.120.222.0/23 | 512 | APNIC | JP | 2nd Mar 2011 |
| 153.123.128.0/17 | 32.8k | APNIC | JP | 2nd Mar 2011 |
| 153.123.32.0/19 | 8.2k | APNIC | JP | 2nd Mar 2011 |
| 153.123.64.0/18 | 16.4k | APNIC | JP | 2nd Mar 2011 |
| 153.124.0.0/17 | 32.8k | APNIC | JP | 12th Mar 2011 |
| 153.124.240.0/20 | 4.1k | APNIC | JP | 12th Mar 2011 |
| 153.125.240.0/20 | 4.1k | APNIC | JP | 2nd Mar 2011 |
| 153.79.80.0/20 | 4.1k | APNIC | JP | 23rd Sept 1991 |
| 154.34.0.0/18 | 16.4k | APNIC | JP | 13th May 1996 |
| 155.160.0.0/16 | 65.5k | APNIC | JP | 14th Sept 1993 |
| 157.101.0.0/18 | 16.4k | APNIC | JP | 8th Feb 1992 |
| 157.104.0.0/16 | 65.5k | APNIC | JP | 8th Feb 1992 |
| 157.106.0.0/16 | 65.5k | APNIC | JP | 8th Feb 1992 |
| 157.108.0.0/16 | 65.5k | APNIC | JP | 8th Feb 1992 |
| 157.11.0.0/16 | 65.5k | APNIC | JP | 13th Apr 1993 |
| 157.112.128.0/20 | 4.1k | APNIC | JP | 8th Feb 1992 |
| 157.112.96.0/23 | 512 | APNIC | JP | 8th Feb 1992 |
| 157.112.98.0/24 | 256 | APNIC | JP | 8th Feb 1992 |
| 157.115.0.0/16 | 65.5k | APNIC | JP | 8th Feb 1992 |
| 157.116.0.0/16 | 65.5k | APNIC | JP | 8th Feb 1992 |
| 157.117.0.0/16 | 65.5k | APNIC | JP | 8th Feb 1992 |