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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,108 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 186.121.190.0/24 | 256 | LACNIC |  AR | 16th Mar 2012 |
| 186.189.252.0/22 | 1k | LACNIC | AR | 13th Jun 2014 |
| 186.195.172.0/22 | 1k | LACNIC |  BR | 10th May 2010 |
| 186.195.176.0/20 | 4.1k | LACNIC | BR | 28th Mar 2012 |
| 186.195.246.0/24 | 256 | LACNIC | AR | 30th Jun 2020 |
| 186.195.248.0/22 | 1k | LACNIC |  TT | 24th Jun 2020 |
| 186.196.100.0/22 | 1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.104.0/21 | 2k | LACNIC | BR | 29th Mar 2010 |
| 186.196.112.0/20 | 4.1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.15.0/24 | 256 | LACNIC | BR | 29th Mar 2010 |
| 186.196.16.0/21 | 2k | LACNIC | BR | 29th Mar 2010 |
| 186.196.24.0/22 | 1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.28.0/22 | 1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.32.0/20 | 4.1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.64.0/22 | 1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.68.0/22 | 1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.72.0/23 | 512 | LACNIC | BR | 29th Mar 2010 |
| 186.196.74.0/24 | 256 | LACNIC | BR | 29th Mar 2010 |
| 186.196.75.0/24 | 256 | LACNIC | BR | 29th Mar 2010 |
| 186.196.77.0/24 | 256 | LACNIC | BR | 29th Mar 2010 |
| 186.196.80.0/20 | 4.1k | LACNIC | BR | 29th Mar 2010 |
| 186.196.96.0/22 | 1k | LACNIC | BR | 29th Mar 2010 |
| 186.208.92.0/22 | 1k | LACNIC | BR | 2nd Jul 2026 |
| 186.232.244.0/24 | 256 | LACNIC | BR | 9th Sept 2010 |
| 186.233.140.0/24 | 256 | LACNIC | BR | 2nd May 2012 |
| 186.233.232.0/22 | 1k | LACNIC | BR | 1st Oct 2010 |
| 186.233.248.0/22 | 1k | LACNIC | BR | 23rd Apr 2012 |
| 186.237.60.0/22 | 1k | LACNIC | BR | 17th Apr 2014 |
| 186.241.16.0/20 | 4.1k | RIPE NCC |  LT | 13th Mar 2025 |
| 186.242.0.0/17 | 32.8k | ARIN |  US | 29th Jul 2026 |
| 186.242.128.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 186.242.208.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 186.243.0.0/18 | 16.4k | LACNIC | BR | 22nd Sept 2010 |
| 186.245.0.0/16 | 65.5k | ARIN | US | 29th Jul 2026 |
| 186.247.0.0/20 | 4.1k | RIPE NCC |  PA | 13th Mar 2025 |
| 186.247.208.0/20 | 4.1k | RIPE NCC | PA | 13th Mar 2025 |
| 186.25.0.0/16 | 65.5k | LACNIC |  VE | 28th Jan 2010 |
| 186.250.148.0/22 | 1k | LACNIC | BR | 11th Jul 2012 |
| 186.251.236.0/22 | 1k | LACNIC | BR | 10th Dec 2010 |
| 186.251.36.0/23 | 512 | LACNIC | BR | 24th Oct 2025 |
| 186.58.0.0/15 | 131k | LACNIC | AR | 30th Dec 2008 |
| 186.96.200.0/21 | 2k | LACNIC |  AW | 22nd Sept 2011 |
| 186.96.224.0/20 | 4.1k | LACNIC | AW | 22nd Oct 2010 |
| 186.96.240.0/21 | 2k | LACNIC | AW | 22nd Oct 2010 |
| 187.102.232.0/22 | 1k | LACNIC | AR | 17th Jun 2026 |
| 187.126.0.0/19 | 8.2k | RIPE NCC | LT | 13th Mar 2025 |
| 187.126.112.0/20 | 4.1k | RIPE NCC | LT | 13th Mar 2025 |
| 187.126.128.0/17 | 32.8k | ARIN | US | 29th Jul 2026 |
| 187.126.64.0/20 | 4.1k | APNIC |  HK | 13th Mar 2025 |
| 187.13.32.0/20 | 4.1k | ARIN | US | 13th Mar 2025 |