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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
26,951 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 207.90.220.0/22 | 1k | ARIN |  US | 7th Jan 2022 |
| 207.92.0.0/19 | 8.2k | ARIN | US | 5th Dec 2024 |
| 207.92.128.0/18 | 16.4k | ARIN | US | 5th Dec 2024 |
| 207.92.224.0/20 | 4.1k | ARIN | US | 5th Dec 2024 |
| 207.92.48.0/20 | 4.1k | ARIN | US | 27th Mar 1996 |
| 207.93.32.0/19 | 8.2k | ARIN | US | 27th Mar 1996 |
| 207.93.64.0/19 | 8.2k | ARIN | US | 5th Dec 2024 |
| 207.95.0.0/16 | 65.5k | ARIN | US | 27th Mar 1996 |
| 208.101.207.0/24 | 256 | ARIN | US | 15th Mar 2006 |
| 208.103.144.0/22 | 1k | ARIN | US | 17th Dec 2021 |
| 208.103.150.0/24 | 256 | ARIN | US | 30th Jul 2018 |
| 208.103.153.0/24 | 256 | ARIN | US | 6th Jul 2016 |
| 208.103.154.0/24 | 256 | ARIN | US | 2nd Aug 2016 |
| 208.103.160.0/24 | 256 | ARIN | US | 1st Nov 2021 |
| 208.103.182.0/24 | 256 | ARIN | US | 13th Apr 2018 |
| 208.103.183.0/24 | 256 | ARIN | US | 2nd Apr 2026 |
| 208.103.80.0/20 | 4.1k | ARIN | US | 16th Sept 2008 |
| 208.114.0.0/19 | 8.2k | ARIN | US | 25th Apr 2006 |
| 208.116.64.0/18 | 16.4k | ARIN | US | 25th May 2007 |
| 208.117.128.0/18 | 16.4k | ARIN | US | 9th May 2006 |
| 208.117.93.0/24 | 256 | ARIN | US | 30th Mar 2016 |
| 208.122.10.0/24 | 256 | ARIN | US | 29th Jul 2026 |
| 208.122.12.0/23 | 512 | ARIN | US | 22nd Jun 2026 |
| 208.122.4.0/24 | 256 | ARIN | US | 8th Oct 2025 |
| 208.122.9.0/24 | 256 | ARIN | US | 2nd Oct 2026 |
| 208.123.209.0/24 | 256 | ARIN | US | 21st Apr 2008 |
| 208.128.0.0/15 | 131k | ARIN | US | 27th Mar 1996 |
| 208.132.0.0/18 | 16.4k | ARIN | US | 27th Mar 1996 |
| 208.132.128.0/17 | 32.8k | ARIN | US | 27th Mar 1996 |
| 208.132.64.0/19 | 8.2k | ARIN | US | 27th Mar 1996 |
| 208.132.96.0/19 | 8.2k | ARIN | US | 27th Mar 1996 |
| 208.138.0.0/20 | 4.1k | ARIN | US | 27th Mar 1996 |
| 208.138.128.0/19 | 8.2k | ARIN | US | 27th Mar 1996 |
| 208.138.160.0/21 | 2k | ARIN | US | 27th Mar 1996 |
| 208.138.176.0/20 | 4.1k | ARIN | US | 27th Mar 1996 |
| 208.138.64.0/18 | 16.4k | ARIN | US | 27th Mar 1996 |
| 208.139.0.0/16 | 65.5k | ARIN | US | 27th Mar 1996 |
| 208.140.0.0/14 | 262k | ARIN | US | 27th Mar 1996 |
| 208.152.0.0/14 | 262k | ARIN | US | 27th Mar 1996 |
| 208.157.192.0/18 | 16.4k | ARIN | US | 27th Mar 1996 |
| 208.162.0.0/16 | 65.5k | ARIN | US | 27th Mar 1996 |
| 208.164.0.0/15 | 131k | ARIN | US | 27th Mar 1996 |
| 208.166.128.0/17 | 32.8k | ARIN | US | 27th Mar 1996 |
| 208.166.32.0/20 | 4.1k | ARIN | US | 27th Mar 1996 |
| 208.168.128.0/18 | 16.4k | ARIN | US | 27th Mar 1996 |
| 208.39.0.0/17 | 32.8k | ARIN | US | 25th Jun 1999 |
| 208.52.136.0/24 | 256 | ARIN | US | 18th Nov 2020 |
| 208.52.143.0/24 | 256 | ARIN | US | 8th Dec 2016 |
| 208.52.169.0/24 | 256 | ARIN | US | 1st Jun 2020 |
| 208.52.184.0/24 | 256 | ARIN | US | 26th Jun 2024 |