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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,108 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 187.14.128.0/18 | 16.4k | RIPE NCC |  AE | 6th Mar 2025 |
| 187.15.192.0/18 | 16.4k | RIPE NCC | AE | 6th Mar 2025 |
| 187.16.192.0/19 | 8.2k | LACNIC |  BR | 13th Dec 2010 |
| 187.165.0.0/16 | 65.5k | LACNIC |  MX | 11th Jul 2011 |
| 187.166.0.0/15 | 131k | LACNIC | MX | 11th Jul 2011 |
| 187.179.160.0/19 | 8.2k | LACNIC | MX | 27th Jul 2010 |
| 187.179.192.0/18 | 16.4k | LACNIC | MX | 27th Jul 2010 |
| 187.19.64.0/20 | 4.1k | LACNIC | BR | 30th Dec 2008 |
| 187.191.128.0/17 | 32.8k | LACNIC | MX | 12th Jun 2014 |
| 187.251.32.0/19 | 8.2k | LACNIC | MX | 29th Nov 2012 |
| 187.4.208.0/20 | 4.1k | RIPE NCC |  LT | 13th Mar 2025 |
| 187.40.16.0/20 | 4.1k | RIPE NCC |  PA | 13th Mar 2025 |
| 187.41.0.0/18 | 16.4k | RIPE NCC |  GB | 20th Feb 2025 |
| 187.41.128.0/17 | 32.8k | ARIN |  US | 10th Apr 2026 |
| 187.41.80.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 187.41.96.0/19 | 8.2k | RIPE NCC | LT | 13th Mar 2025 |
| 187.42.128.0/18 | 16.4k | APNIC |  SG | 20th Feb 2025 |
| 187.42.192.0/18 | 16.4k | ARIN | US | 20th Feb 2025 |
| 187.49.8.0/24 | 256 | LACNIC |  EC | 12th Apr 2022 |
| 187.49.9.0/24 | 256 | LACNIC |  CL | 2nd May 2022 |
| 187.52.224.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.52.32.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.53.128.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 187.53.160.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.53.192.0/20 | 4.1k | APNIC |  HK | 13th Mar 2025 |
| 187.53.80.0/20 | 4.1k | APNIC | HK | 13th Mar 2025 |
| 187.53.96.0/19 | 8.2k | RIPE NCC | LT | 13th Mar 2025 |
| 187.54.0.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.54.224.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.55.0.0/18 | 16.4k | RIPE NCC | AE | 6th Mar 2025 |
| 187.55.112.0/20 | 4.1k | APNIC | HK | 13th Mar 2025 |
| 187.55.128.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.55.160.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.55.64.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.6.160.0/19 | 8.2k | RIPE NCC | LT | 13th Mar 2025 |
| 187.7.16.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 187.7.192.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.7.32.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.7.64.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 187.78.0.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 187.78.128.0/19 | 8.2k | ARIN | US | 13th Mar 2025 |
| 187.78.176.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 187.78.192.0/18 | 16.4k | ARIN | US | 20th Feb 2025 |
| 187.79.0.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 187.79.128.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |
| 187.79.160.0/19 | 8.2k | RIPE NCC | GB | 13th Mar 2025 |
| 187.94.48.0/24 | 256 | LACNIC | BR | 14th Sept 2009 |
| 187.94.50.0/23 | 512 | LACNIC | BR | 14th Sept 2009 |
| 187.94.52.0/23 | 512 | LACNIC | BR | 14th Sept 2009 |
| 187.94.54.0/24 | 256 | LACNIC | BR | 14th Sept 2009 |