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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks
85,578 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 203.15.249.0/24 | 256 | APNIC |  CA | 31st May 1995 |
| 203.15.69.0/24 | 256 | APNIC |  AU | 13th May 1995 |
| 203.15.71.0/24 | 256 | APNIC | AU | 13th May 1995 |
| 203.15.72.0/22 | 1k | APNIC | AU | 13th May 1995 |
| 203.15.76.0/23 | 512 | APNIC | AU | 13th May 1995 |
| 203.15.78.0/23 | 512 | APNIC | AU | 13th May 1995 |
| 203.15.80.0/22 | 1k | APNIC | AU | 13th May 1995 |
| 203.15.84.0/23 | 512 | APNIC | AU | 13th May 1995 |
| 203.15.86.0/24 | 256 | APNIC | AU | 13th May 1995 |
| 203.15.87.0/24 | 256 | APNIC |  CN | 14th Apr 2011 |
| 203.15.88.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.15.95.0/24 | 256 | APNIC | AU | 13th May 1995 |
| 203.152.10.0/24 | 256 | APNIC |  JP | 15th Jan 2003 |
| 203.152.128.0/19 | 8.2k | APNIC | CN | 12th Apr 2011 |
| 203.152.15.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.21.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.23.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.38.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.41.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.45.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.46.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.5.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.51.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.52.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.54.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.59.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.60.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.152.61.0/24 | 256 | APNIC | JP | 15th Jan 2003 |
| 203.153.0.0/22 | 1k | APNIC | CN | 14th Apr 2011 |
| 203.153.160.0/20 | 4.1k | APNIC |  TH | 1st Sept 2005 |
| 203.153.176.0/20 | 4.1k | APNIC | TH | 13th Sept 2006 |
| 203.158.16.0/21 | 2k | APNIC | CN | 7th Apr 2006 |
| 203.16.10.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.12.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.16.132.0/24 | 256 | APNIC | AU | 6th Jun 1995 |
| 203.16.133.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.16.0/21 | 2k | APNIC | CN | 14th Apr 2011 |
| 203.16.161.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.162.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.168.0/24 | 256 | APNIC | AU | 7th Jun 1995 |
| 203.16.173.0/24 | 256 | APNIC | AU | 12th Jun 1995 |
| 203.16.176.0/24 | 256 | APNIC | AU | 12th Jun 1995 |
| 203.16.186.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.16.197.0/24 | 256 | APNIC | AU | 13th Jun 1995 |
| 203.16.198.0/24 | 256 | APNIC | AU | 13th Jun 1995 |
| 203.16.204.0/24 | 256 | APNIC | AU | 14th Jun 1995 |
| 203.16.228.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.238.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.240.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.245.0/24 | 256 | APNIC | CN | 14th Apr 2011 |