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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks
84,584 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 37.77.32.0/20 | 4.1k | RIPE NCC |  FR | 1st Feb 2012 |
| 37.77.64.0/20 | 4.1k | RIPE NCC |  IQ | 1st Feb 2012 |
| 37.9.128.0/21 | 2k | RIPE NCC |  RU | 14th Dec 2011 |
| 37.99.208.0/21 | 2k | RIPE NCC |  IE | 8th Feb 2012 |
| 39.0.0.0/24 | 256 | APNIC |  CN | 14th Apr 2011 |
| 39.0.1.0/24 | 256 | APNIC |  AU | 2nd Mar 2011 |
| 39.0.128.0/17 | 32.8k | APNIC | CN | 12th Apr 2011 |
| 39.0.16.0/20 | 4.1k | APNIC | CN | 12th Apr 2011 |
| 39.0.2.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 39.0.32.0/19 | 8.2k | APNIC | CN | 12th Apr 2011 |
| 39.0.4.0/22 | 1k | APNIC | CN | 14th Apr 2011 |
| 39.0.64.0/18 | 16.4k | APNIC | CN | 12th Apr 2011 |
| 39.0.8.0/21 | 2k | APNIC | CN | 12th Apr 2011 |
| 39.109.124.0/23 | 512 | APNIC |  HK | 5th Apr 2011 |
| 39.109.48.0/24 | 256 | APNIC | HK | 5th Apr 2011 |
| 4.128.0.0/12 | 1M | ARIN |  US | 17th Jul 2019 |
| 40.149.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.150.0.0/16 | 65.5k | ARIN | US | 4th Dec 2023 |
| 40.152.0.0/15 | 131k | ARIN | US | 23rd Apr 1991 |
| 40.154.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.158.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.16.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.163.0.0/16 | 65.5k | ARIN | US | 18th Feb 2022 |
| 40.17.0.0/16 | 65.5k | RIPE NCC |  GB | 23rd Apr 1991 |
| 40.18.0.0/15 | 131k | ARIN | US | 23rd Apr 1991 |
| 40.186.0.0/15 | 131k | ARIN | US | 4th Dec 2023 |
| 40.189.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.194.0.0/16 | 65.5k | ARIN | US | 16th Jun 2023 |
| 40.195.0.0/16 | 65.5k | ARIN | US | 21st Oct 2022 |
| 40.20.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.202.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.203.0.0/16 | 65.5k | ARIN | US | 13th Feb 2023 |
| 40.21.0.0/16 | 65.5k | RIPE NCC | GB | 23rd Apr 1991 |
| 40.211.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.215.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.217.0.0/16 | 65.5k | ARIN | US | 13th Feb 2023 |
| 40.219.0.0/16 | 65.5k | ARIN | US | 13th Feb 2023 |
| 40.22.0.0/15 | 131k | ARIN | US | 23rd Apr 1991 |
| 40.221.0.0/16 | 65.5k | ARIN | US | 13th Feb 2023 |
| 40.222.0.0/16 | 65.5k | ARIN | US | 13th Feb 2023 |
| 40.225.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.230.0.0/16 | 65.5k | ARIN | US | 13th Feb 2023 |
| 40.233.128.0/17 | 32.8k | ARIN | US | 23rd Apr 1991 |
| 40.238.0.0/16 | 65.5k | ARIN | US | 4th Dec 2023 |
| 40.239.0.0/16 | 65.5k | ARIN | US | 28th Sept 2022 |
| 40.24.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.240.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |
| 40.241.0.0/16 | 65.5k | ARIN | US | 28th Jul 2022 |
| 40.242.0.0/16 | 65.5k | ARIN | US | 28th Jul 2022 |
| 40.243.0.0/16 | 65.5k | ARIN | US | 23rd Apr 1991 |