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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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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 |
|---|---|---|---|---|
| 183.181.138.0/23 | 512 | APNIC |  JP | 1st Dec 2009 |
| 183.181.140.0/23 | 512 | APNIC | JP | 1st Dec 2009 |
| 183.183.0.0/16 | 65.5k | APNIC | JP | 7th Dec 2009 |
| 192.104.172.0/24 | 256 | APNIC | JP | 11th Jun 1991 |
| 192.104.247.0/24 | 256 | APNIC | JP | 17th Jun 1991 |
| 192.135.101.0/24 | 256 | APNIC | JP | 7th May 1993 |
| 192.135.103.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.104.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.105.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.106.0/23 | 512 | APNIC | JP | 5th May 1992 |
| 192.135.108.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.94.0/24 | 256 | APNIC | JP | 28th Apr 1993 |
| 192.135.96.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.146.184.0/24 | 256 | APNIC | JP | 3rd Feb 1992 |
| 192.152.69.0/24 | 256 | APNIC | JP | 8th Apr 1992 |
| 192.153.113.0/24 | 256 | APNIC | JP | 29th Jun 1993 |
| 192.156.141.0/24 | 256 | APNIC | JP | 25th Jun 1992 |
| 192.156.150.0/24 | 256 | APNIC | JP | 25th Jun 1992 |
| 192.156.154.0/24 | 256 | APNIC | JP | 25th Jun 1992 |
| 192.156.159.0/24 | 256 | APNIC | JP | 25th Jun 1992 |
| 192.16.179.0/24 | 256 | APNIC | JP | 4th Nov 1986 |
| 192.172.227.0/24 | 256 | APNIC | JP | 27th Jul 1992 |
| 192.172.228.0/24 | 256 | APNIC | JP | 27th Jul 1992 |
| 192.172.229.0/24 | 256 | APNIC | JP | 6th Nov 2007 |
| 192.172.230.0/23 | 512 | APNIC | JP | 7th Nov 2007 |
| 192.172.235.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.241.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.242.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.172.243.0/24 | 256 | APNIC | JP | 7th Aug 1992 |
| 192.188.75.0/24 | 256 | APNIC | JP | 23rd Jun 1993 |
| 192.188.76.0/24 | 256 | APNIC | JP | 23rd Jun 1993 |
| 192.188.77.0/24 | 256 | APNIC | JP | 15th Jun 1993 |
| 192.188.78.0/23 | 512 | APNIC | JP | 15th Jun 1993 |
| 192.188.92.0/24 | 256 | APNIC | JP | 15th Feb 1994 |
| 192.26.96.0/24 | 256 | APNIC | JP | 26th Feb 1987 |
| 192.31.116.0/22 | 1k | APNIC | JP | 8th Jul 1987 |
| 192.31.120.0/24 | 256 | APNIC | JP | 8th Jul 1987 |
| 192.31.122.0/23 | 512 | APNIC | JP | 8th Jul 1987 |
| 192.31.124.0/24 | 256 | APNIC | JP | 8th Jul 1987 |
| 192.31.197.0/24 | 256 | APNIC | JP | 28th Aug 1987 |
| 192.41.178.0/23 | 512 | APNIC | JP | 20th Jun 1988 |
| 192.41.180.0/22 | 1k | APNIC | JP | 20th Jun 1988 |
| 192.41.184.0/21 | 2k | APNIC | JP | 20th Jun 1988 |
| 192.41.193.0/24 | 256 | APNIC | JP | 20th Jun 1988 |
| 192.41.194.0/23 | 512 | APNIC | JP | 20th Jun 1988 |
| 192.41.196.0/23 | 512 | APNIC | JP | 20th Jun 1988 |
| 192.42.103.0/24 | 256 | APNIC | JP | 21st Sept 1988 |
| 192.42.104.0/22 | 1k | APNIC | JP | 21st Sept 1988 |
| 192.43.189.0/24 | 256 | APNIC | JP | 11th Feb 2011 |
| 192.47.0.0/24 | 256 | APNIC | JP | 12th Jan 1989 |