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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,619 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 74.121.132.0/22 | 1k | ARIN |  US | 19th Jan 2010 |
| 74.121.200.0/22 | 1k | ARIN | US | 25th Jan 2010 |
| 74.121.208.0/21 | 2k | ARIN | US | 25th Jan 2010 |
| 74.122.176.0/22 | 1k | ARIN | US | 19th Feb 2010 |
| 74.122.180.0/22 | 1k | ARIN | US | 22nd Feb 2010 |
| 74.122.20.0/22 | 1k | ARIN | US | 1st Feb 2010 |
| 74.122.24.0/24 | 256 | RIPE NCC |  DE | 12th Jul 2019 |
| 74.122.248.0/21 | 2k | ARIN | US | 1st Mar 2010 |
| 74.122.32.0/22 | 1k | ARIN | US | 1st Feb 2010 |
| 74.122.5.0/24 | 256 | ARIN | US | 29th Jan 2010 |
| 74.123.148.0/22 | 1k | ARIN | US | 19th Mar 2010 |
| 74.123.184.0/22 | 1k | ARIN | US | 8th Oct 2013 |
| 74.123.216.0/21 | 2k | ARIN | US | 29th Mar 2010 |
| 74.123.4.0/22 | 1k | ARIN | US | 2nd Mar 2010 |
| 74.124.199.0/24 | 256 | ARIN | US | 22nd Mar 2007 |
| 74.124.201.0/24 | 256 | ARIN | US | 22nd Mar 2007 |
| 74.124.216.0/24 | 256 | ARIN | US | 22nd Mar 2007 |
| 74.170.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.181.0.0/16 | 65.5k | ARIN | US | 30th Oct 2006 |
| 74.182.0.0/15 | 131k | ARIN | US | 30th Oct 2006 |
| 74.184.0.0/15 | 131k | ARIN | US | 30th Oct 2006 |
| 74.187.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.189.0.0/16 | 65.5k | ARIN | US | 30th Oct 2006 |
| 74.201.16.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.168.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.196.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.210.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.212.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.220.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.230.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.232.0/22 | 1k | ARIN | US | 13th Nov 2006 |
| 74.201.238.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.24.0/21 | 2k | ARIN | US | 13th Nov 2006 |
| 74.201.242.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.201.246.0/23 | 512 | ARIN | US | 13th Nov 2006 |
| 74.205.200.0/22 | 1k | ARIN | US | 21st May 2024 |
| 74.205.247.0/24 | 256 | ARIN | US | 20th Nov 2023 |
| 74.206.0.0/19 | 8.2k | ARIN | US | 12th Oct 2006 |
| 74.209.166.0/23 | 512 | ARIN | US | 19th May 2009 |
| 74.209.175.0/24 | 256 | RIPE NCC |  GB | 19th May 2009 |
| 74.209.178.0/23 | 512 | ARIN | US | 12th Jan 2026 |
| 74.209.183.0/24 | 256 | ARIN | US | 16th Apr 2026 |
| 74.212.128.0/21 | 2k | ARIN | US | 8th Dec 2006 |
| 74.212.140.0/22 | 1k | ARIN | US | 8th Dec 2006 |
| 74.212.184.0/21 | 2k | ARIN | US | 8th Dec 2006 |
| 74.217.36.0/22 | 1k | ARIN | US | 22nd Jan 2008 |
| 74.229.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.236.0.0/16 | 65.5k | ARIN | US | 12th Dec 2025 |
| 74.251.0.0/16 | 65.5k | ARIN | US | 17th Jan 2006 |
| 74.51.144.0/20 | 4.1k | ARIN | US | 31st Jul 2008 |