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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 203.16.27.0/24 | 256 | APNIC |  CN | 14th Apr 2011 |
| 203.16.38.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.49.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.50.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.16.58.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.16.63.0/24 | 256 | APNIC | CN | 9th Jun 2016 |
| 203.160.104.0/21 | 2k | APNIC | CN | 14th Apr 2011 |
| 203.160.144.0/20 | 4.1k | APNIC |  TW | 13th Apr 2006 |
| 203.160.96.0/21 | 2k | APNIC |  VN | 30th Sept 2003 |
| 203.161.0.0/22 | 1k | APNIC | CN | 14th Apr 2011 |
| 203.161.176.0/23 | 512 | APNIC |  PH | 20th Aug 2009 |
| 203.161.179.0/24 | 256 | APNIC |  PK | 17th Aug 2016 |
| 203.161.182.0/24 | 256 | APNIC |  AU | 24th Aug 2009 |
| 203.161.183.0/24 | 256 | APNIC | CN | 9th Jun 2016 |
| 203.161.186.0/24 | 256 | APNIC | AU | 27th Aug 2009 |
| 203.161.190.0/23 | 512 | APNIC |  ID | 1st Sept 2009 |
| 203.161.192.0/19 | 8.2k | APNIC | CN | 20th Sept 2005 |
| 203.163.128.0/18 | 16.4k | APNIC | VN | 6th Apr 2011 |
| 203.167.24.0/22 | 1k | APNIC | AU | 25th Nov 2015 |
| 203.167.28.0/22 | 1k | APNIC | CN | 26th Nov 2015 |
| 203.168.192.0/20 | 4.1k | APNIC |  SG | 30th Jun 2000 |
| 203.169.52.0/23 | 512 | APNIC | ID | 28th Dec 2023 |
| 203.17.10.0/24 | 256 | APNIC | AU | 22nd Jun 1995 |
| 203.17.122.0/24 | 256 | APNIC | AU | 14th Jul 1995 |
| 203.17.136.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.140.0/22 | 1k | APNIC | AU | 14th Jul 1995 |
| 203.17.144.0/22 | 1k | APNIC | AU | 14th Jul 1995 |
| 203.17.153.0/24 | 256 | APNIC | AU | 15th Jul 1995 |
| 203.17.16.0/23 | 512 | APNIC | AU | 22nd Jun 1995 |
| 203.17.164.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.18.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.184.0/24 | 256 | APNIC | AU | 26th Jul 1995 |
| 203.17.187.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.188.0/24 | 256 | APNIC |  JP | 26th Jul 1995 |
| 203.17.190.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.17.196.0/22 | 1k | APNIC | AU | 26th Jul 1995 |
| 203.17.2.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.20.0/24 | 256 | APNIC | AU | 22nd Jun 1995 |
| 203.17.21.0/24 | 256 | APNIC | ID | 15th Mar 2011 |
| 203.17.230.0/24 | 256 | APNIC | AU | 27th Jul 1995 |
| 203.17.231.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.233.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.239.0/24 | 256 | APNIC | AU | 31st Jul 1995 |
| 203.17.246.0/24 | 256 | APNIC | AU | 31st Jul 1995 |
| 203.17.248.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.249.0/24 | 256 | APNIC | CN | 9th Jun 2016 |
| 203.17.252.0/24 | 256 | APNIC | AU | 31st Jul 1995 |
| 203.17.254.0/24 | 256 | APNIC | AU | 31st Jul 1995 |
| 203.17.255.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.17.26.0/23 | 512 | APNIC | AU | 5th Jul 1995 |