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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,356 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.207.246.0/23 | 512 | ARIN |  US | 8th Apr 1995 |
| 205.207.25.0/24 | 256 | ARIN |  CA | 8th Apr 1995 |
| 205.207.29.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.30.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.31.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.32.0/19 | 8.2k | ARIN | CA | 8th Apr 1995 |
| 205.207.4.0/22 | 1k | ARIN | CA | 1st Aug 1995 |
| 205.207.64.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.67.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.68.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.70.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.72.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.73.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.74.0/24 | 256 | ARIN | US | 8th Apr 1995 |
| 205.207.75.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.8.0/21 | 2k | ARIN | CA | 1st Aug 1995 |
| 205.207.91.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.92.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.207.93.0/24 | 256 | ARIN | CA | 29th Aug 1995 |
| 205.207.96.0/24 | 256 | ARIN | CA | 7th Sept 1995 |
| 205.207.97.0/24 | 256 | ARIN | CA | 7th Sept 1995 |
| 205.207.99.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.208.128.0/17 | 32.8k | ARIN | US | 8th Apr 1995 |
| 205.209.0.0/24 | 256 | ARIN | US | 27th Dec 2011 |
| 205.209.1.0/24 | 256 | ARIN | CA | 17th Oct 1995 |
| 205.209.24.0/24 | 256 | ARIN | US | 18th Mar 2026 |
| 205.209.27.0/24 | 256 | ARIN | US | 1st Jun 2026 |
| 205.209.28.0/24 | 256 | RIPE NCC | US | 2nd Mar 2017 |
| 205.209.4.0/24 | 256 | ARIN | CA | 11th May 1995 |
| 205.209.5.0/24 | 256 | ARIN | CA | 11th May 1995 |
| 205.209.6.0/24 | 256 | ARIN | CA | 11th May 1995 |
| 205.209.8.0/24 | 256 | ARIN | CA | 25th Jan 1996 |
| 205.210.0.0/24 | 256 | ARIN | US | 3rd Apr 2025 |
| 205.210.1.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.105.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.106.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.107.0/24 | 256 | ARIN | CA | 27th Feb 1997 |
| 205.210.124.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.125.0/24 | 256 | ARIN | US | 29th Dec 2011 |
| 205.210.126.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.127.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.129.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.130.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.131.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.134.0/23 | 512 | ARIN | CA | 8th Apr 1995 |
| 205.210.136.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.137.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.138.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.139.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.142.0/24 | 256 | ARIN | US | 8th Apr 1995 |