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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.248.239.0/24 | 256 | ARIN |  US | 2nd Jul 2025 |
| 199.248.24.0/22 | 1k | ARIN | US | 3rd May 1994 |
| 199.248.242.0/24 | 256 | ARIN | US | 6th Oct 1994 |
| 199.248.243.0/24 | 256 | ARIN | US | 6th Oct 1994 |
| 199.248.244.0/24 | 256 | ARIN | US | 25th Sept 2015 |
| 199.248.246.0/24 | 256 | ARIN | US | 6th Oct 1994 |
| 199.248.247.0/24 | 256 | ARIN | US | 7th Oct 1994 |
| 199.248.248.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.249.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.250.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.251.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.252.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.253.0/24 | 256 | ARIN | US | 10th Oct 1994 |
| 199.248.255.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 199.248.28.0/23 | 512 | ARIN | US | 3rd May 1994 |
| 199.248.30.0/24 | 256 | ARIN | US | 3rd May 1994 |
| 199.248.32.0/20 | 4.1k | ARIN | US | 29th Apr 1994 |
| 199.248.48.0/21 | 2k | ARIN | US | 29th Apr 1994 |
| 199.248.56.0/22 | 1k | ARIN | US | 29th Apr 1994 |
| 199.248.60.0/23 | 512 | ARIN | US | 29th Apr 1994 |
| 199.249.104.0/22 | 1k | ARIN | US | 20th May 1994 |
| 199.249.108.0/24 | 256 | ARIN | US | 20th May 1994 |
| 199.249.128.0/22 | 1k | ARIN | US | 25th May 1994 |
| 199.249.132.0/23 | 512 | ARIN | US | 25th May 1994 |
| 199.249.134.0/24 | 256 | ARIN | US | 26th May 1994 |
| 199.249.136.0/23 | 512 | ARIN | US | 27th May 1994 |
| 199.249.138.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.139.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.143.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.144.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.145.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.146.0/23 | 512 | ARIN | US | 27th May 1994 |
| 199.249.148.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.149.0/24 | 256 | ARIN | US | 27th May 1994 |
| 199.249.150.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.151.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.152.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.153.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.154.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.158.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.160.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.163.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.164.0/24 | 256 | ARIN | US | 31st May 1994 |
| 199.249.172.0/24 | 256 | ARIN | US | 1st Jun 1994 |
| 199.249.173.0/24 | 256 | ARIN | US | 1st Jun 1994 |
| 199.249.174.0/24 | 256 | ARIN | US | 1st Jun 1994 |
| 199.249.179.0/24 | 256 | ARIN | US | 1st Jun 1994 |
| 199.249.189.0/24 | 256 | ARIN | US | 1st Jun 1994 |
| 199.249.191.0/24 | 256 | ARIN | US | 2nd Jun 1994 |
| 199.249.193.0/24 | 256 | ARIN | US | 2nd Jun 1994 |