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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,960 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 36.37.48.0/20 | 4.1k | APNIC |  CN | 12th Apr 2011 |
| 36.50.109.0/24 | 256 | APNIC |  ID | 14th Dec 2023 |
| 36.50.120.0/23 | 512 | APNIC | ID | 14th Dec 2023 |
| 36.50.126.0/23 | 512 | APNIC | ID | 15th Dec 2023 |
| 36.50.136.0/23 | 512 | APNIC | ID | 15th Dec 2023 |
| 36.50.16.0/23 | 512 | APNIC |  VN | 27th Nov 2023 |
| 36.50.208.0/23 | 512 | APNIC | VN | 22nd Dec 2023 |
| 36.50.215.0/24 | 256 | APNIC | ID | 22nd Dec 2023 |
| 36.50.216.0/23 | 512 | APNIC | ID | 22nd Dec 2023 |
| 36.50.242.0/23 | 512 | APNIC | ID | 27th Dec 2023 |
| 36.50.244.0/23 | 512 | APNIC | ID | 27th Dec 2023 |
| 36.50.246.0/23 | 512 | APNIC | ID | 28th Dec 2023 |
| 36.50.254.0/23 | 512 | APNIC | CN | 28th Dec 2023 |
| 36.50.28.0/23 | 512 | APNIC | VN | 27th Nov 2023 |
| 36.52.112.0/21 | 2k | APNIC |  JP | 3rd Feb 2011 |
| 36.52.120.0/22 | 1k | APNIC | JP | 3rd Feb 2011 |
| 36.52.124.0/23 | 512 | APNIC | JP | 3rd Feb 2011 |
| 36.52.144.0/21 | 2k | APNIC | JP | 3rd Feb 2011 |
| 36.52.16.0/21 | 2k | APNIC | JP | 3rd Feb 2011 |
| 36.52.168.0/22 | 1k | APNIC | JP | 3rd Feb 2011 |
| 36.52.172.0/23 | 512 | APNIC | JP | 3rd Feb 2011 |
| 36.52.224.0/21 | 2k | APNIC | JP | 3rd Feb 2011 |
| 36.52.232.0/22 | 1k | APNIC | JP | 3rd Feb 2011 |
| 36.52.236.0/23 | 512 | APNIC | JP | 3rd Feb 2011 |
| 36.52.24.0/23 | 512 | APNIC | JP | 3rd Feb 2011 |
| 37.1.144.0/24 | 256 | RIPE NCC |  TR | 12th Dec 2011 |
| 37.1.146.0/23 | 512 | RIPE NCC | TR | 12th Dec 2011 |
| 37.1.148.0/23 | 512 | RIPE NCC | TR | 12th Dec 2011 |
| 37.1.150.0/24 | 256 | RIPE NCC | TR | 12th Dec 2011 |
| 37.10.112.0/24 | 256 | RIPE NCC |  AT | 15th Dec 2011 |
| 37.10.116.0/24 | 256 | RIPE NCC |  IM | 15th Dec 2011 |
| 37.10.117.0/24 | 256 | RIPE NCC |  IR | 15th Dec 2011 |
| 37.10.120.0/22 | 1k | RIPE NCC |  DE | 15th Dec 2011 |
| 37.122.128.0/21 | 2k | RIPE NCC | DE | 14th Feb 2012 |
| 37.122.192.0/21 | 2k | RIPE NCC |  GB | 14th Feb 2012 |
| 37.122.208.0/21 | 2k | RIPE NCC | DE | 14th Feb 2012 |
| 37.122.224.0/20 | 4.1k | RIPE NCC | TR | 15th Feb 2012 |
| 37.123.0.0/18 | 16.4k | RIPE NCC | TR | 15th Feb 2012 |
| 37.123.232.0/21 | 2k | RIPE NCC |  BE | 16th Feb 2012 |
| 37.128.136.0/21 | 2k | RIPE NCC |  IT | 17th Feb 2012 |
| 37.128.192.0/21 | 2k | ARIN |  US | 22nd May 2024 |
| 37.131.176.0/23 | 512 | RIPE NCC | DE | 23rd Feb 2012 |
| 37.131.178.0/24 | 256 | RIPE NCC | DE | 23rd Feb 2012 |
| 37.140.253.0/24 | 256 | RIPE NCC |  GE | 21st Sept 2021 |
| 37.143.88.0/21 | 2k | RIPE NCC |  UA | 2nd Mar 2012 |
| 37.148.160.0/24 | 256 | RIPE NCC |  NL | 6th Mar 2012 |
| 37.148.162.0/23 | 512 | RIPE NCC | NL | 6th Mar 2012 |
| 37.148.164.0/24 | 256 | RIPE NCC | NL | 6th Mar 2012 |
| 37.148.165.0/24 | 256 | RIPE NCC | NL | 6th Mar 2012 |
| 37.148.166.0/23 | 512 | RIPE NCC | NL | 6th Mar 2012 |