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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,300 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.196.200.0/24 | 256 | ARIN |  US | 17th Nov 1995 |
| 205.196.201.0/24 | 256 | ARIN | US | 13th Dec 2011 |
| 205.196.28.0/22 | 1k | ARIN | US | 1st Nov 1995 |
| 205.196.48.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.49.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.50.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 205.196.51.0/24 | 256 | ARIN | US | 14th Nov 1995 |
| 205.196.52.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.53.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.54.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.55.0/24 | 256 | ARIN | US | 20th Nov 1995 |
| 205.196.56.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.57.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.58.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.59.0/24 | 256 | ARIN | US | 14th Nov 1995 |
| 205.196.60.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.61.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.62.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.66.0/24 | 256 | ARIN | US | 13th Feb 2012 |
| 205.196.67.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.68.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.69.0/24 | 256 | ARIN | US | 20th Nov 1995 |
| 205.196.70.0/24 | 256 | ARIN | US | 15th Feb 2012 |
| 205.196.71.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.72.0/24 | 256 | ARIN | US | 31st Aug 1995 |
| 205.196.73.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.74.0/24 | 256 | ARIN | US | 25th Aug 1995 |
| 205.196.75.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.76.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.96.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.97.0/24 | 256 | ARIN | US | 1st Nov 1995 |
| 205.196.98.0/24 | 256 | ARIN | US | 7th Dec 2011 |
| 205.196.99.0/24 | 256 | ARIN | US | 25th Oct 1995 |
| 205.203.0.0/19 | 8.2k | ARIN | US | 7th Apr 1995 |
| 205.203.208.0/21 | 2k | ARIN | US | 26th May 1995 |
| 205.203.224.0/19 | 8.2k | ARIN | US | 8th Jun 1995 |
| 205.207.156.0/22 | 1k | ARIN | US | 2nd Dec 2008 |
| 205.207.170.0/23 | 512 | ARIN | US | 22nd Sept 1995 |
| 205.207.246.0/23 | 512 | ARIN | US | 8th Apr 1995 |
| 205.207.74.0/24 | 256 | ARIN | US | 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 |
| 205.209.24.0/24 | 256 | ARIN | US | 18th Mar 2026 |
| 205.209.27.0/24 | 256 | ARIN | US | 1st Jun 2026 |
| 205.210.0.0/24 | 256 | ARIN | US | 3rd Apr 2025 |
| 205.210.125.0/24 | 256 | ARIN | US | 29th Dec 2011 |
| 205.210.142.0/24 | 256 | ARIN | US | 8th Apr 1995 |
| 205.210.145.0/24 | 256 | ARIN | US | 5th Jan 2012 |
| 205.210.149.0/24 | 256 | ARIN | US | 22nd Dec 2011 |
| 205.210.186.0/23 | 512 | ARIN | US | 16th Mar 2012 |