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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,001 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 153.79.184.0/23 | 512 | RIPE NCC |  RU | 23rd Sept 1991 |
| 153.79.186.0/23 | 512 | RIPE NCC | RU | 23rd Sept 1991 |
| 153.79.188.0/22 | 1k | RIPE NCC | RU | 23rd Sept 1991 |
| 153.79.192.0/19 | 8.2k | RIPE NCC |  US | 23rd Sept 1991 |
| 153.79.64.0/20 | 4.1k | ARIN | US | 23rd Sept 1991 |
| 153.79.80.0/20 | 4.1k | APNIC |  JP | 23rd Sept 1991 |
| 153.79.96.0/20 | 4.1k | ARIN | US | 23rd Sept 1991 |
| 153.8.0.0/16 | 65.5k | ARIN | US | 12th Sept 1991 |
| 153.80.180.0/22 | 1k | RIPE NCC | RU | 23rd Sept 1991 |
| 153.80.186.0/24 | 256 | RIPE NCC | RU | 23rd Sept 1991 |
| 153.80.248.0/24 | 256 | RIPE NCC | RU | 23rd Sept 1991 |
| 153.80.252.0/24 | 256 | RIPE NCC | RU | 23rd Sept 1991 |
| 153.80.254.0/23 | 512 | RIPE NCC | RU | 23rd Sept 1991 |
| 153.81.0.0/16 | 65.5k | ARIN | US | 23rd Sept 1991 |
| 153.82.0.0/15 | 131k | ARIN | US | 23rd Sept 1991 |
| 153.89.0.0/16 | 65.5k | ARIN |  BE | 23rd Sept 1991 |
| 153.92.41.0/24 | 256 | RIPE NCC |  CH | 23rd Sept 1991 |
| 153.92.47.0/24 | 256 | RIPE NCC | CH | 23rd Sept 1991 |
| 153.93.0.0/16 | 65.5k | RIPE NCC |  DE | 23rd Sept 1991 |
| 153.94.0.0/20 | 4.1k | RIPE NCC | DE | 23rd Sept 1991 |
| 154.0.144.0/22 | 1k | AFRINIC |  CI | 28th Feb 2020 |
| 154.0.148.0/22 | 1k | AFRINIC | CI | 28th Feb 2020 |
| 154.0.32.0/19 | 8.2k | AFRINIC |  GA | 16th Jul 2013 |
| 154.119.128.0/20 | 4.1k | AFRINIC | CI | 28th Feb 2020 |
| 154.126.224.0/19 | 8.2k | AFRINIC |  TZ | 28th Feb 2014 |
| 154.15.0.0/16 | 65.5k | ARIN | US | 3rd Aug 2026 |
| 154.2.0.0/16 | 65.5k | ARIN | US | 5th Feb 1992 |
| 154.34.0.0/18 | 16.4k | APNIC | JP | 13th May 1996 |
| 154.35.0.0/16 | 65.5k | ARIN | US | 5th Feb 1992 |
| 154.4.0.0/16 | 65.5k | ARIN | US | 5th Feb 1992 |
| 154.65.24.0/22 | 1k | AFRINIC |  LR | 15th Feb 2018 |
| 154.65.56.0/22 | 1k | AFRINIC | CI | 28th Feb 2020 |
| 154.66.116.0/22 | 1k | AFRINIC | CI | 28th Feb 2020 |
| 154.66.212.0/22 | 1k | AFRINIC | CI | 28th Feb 2020 |
| 154.66.80.0/22 | 1k | AFRINIC |  AO | 14th Oct 2013 |
| 154.66.96.0/22 | 1k | AFRINIC | CI | 28th Feb 2020 |
| 154.68.128.0/19 | 8.2k | AFRINIC |  TD | 11th Apr 2016 |
| 154.71.32.0/19 | 8.2k | AFRINIC | CI | 28th Feb 2020 |
| 154.71.64.0/18 | 16.4k | AFRINIC | CI | 28th Feb 2020 |
| 154.72.0.0/22 | 1k | AFRINIC | CI | 28th Feb 2020 |
| 154.73.56.0/22 | 1k | AFRINIC |  GN | 24th Jun 2014 |
| 154.8.112.0/21 | 2k | APNIC |  HK | 5th Feb 1992 |
| 154.8.120.0/22 | 1k | APNIC |  AU | 5th Feb 1992 |
| 154.8.126.0/23 | 512 | APNIC | HK | 5th Feb 1992 |
| 154.8.64.0/19 | 8.2k | APNIC | HK | 5th Feb 1992 |
| 154.8.96.0/20 | 4.1k | APNIC |  ID | 5th Feb 1992 |
| 155.1.0.0/16 | 65.5k | ARIN | US | 30th Oct 1991 |
| 155.103.104.0/22 | 1k | ARIN | US | 13th Jan 2026 |
| 155.103.110.0/24 | 256 | ARIN | US | 13th Jan 2026 |
| 155.103.111.0/24 | 256 | ARIN | US | 13th Jan 2026 |