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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,310 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.79.191.0/24 | 256 | ARIN |  US | 7th Feb 1994 |
| 199.79.192.0/24 | 256 | ARIN | US | 7th Feb 1994 |
| 199.79.194.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.195.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.196.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.197.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.198.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.200.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.201.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.204.0/24 | 256 | ARIN | US | 8th Feb 1994 |
| 199.79.205.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.206.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.207.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.208.0/22 | 1k | ARIN | US | 8th Feb 1994 |
| 199.79.212.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.213.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.214.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.215.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.218.0/23 | 512 | ARIN | US | 9th Feb 1994 |
| 199.79.220.0/23 | 512 | ARIN | US | 9th Feb 1994 |
| 199.79.222.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.223.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.226.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.229.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.230.0/24 | 256 | ARIN | US | 9th Feb 1994 |
| 199.79.231.0/24 | 256 | ARIN | US | 15th Sept 2015 |
| 199.79.232.0/22 | 1k | ARIN | US | 9th Feb 1994 |
| 199.79.236.0/24 | 256 | ARIN | US | 28th Dec 2018 |
| 199.79.237.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.238.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.239.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.24.0/22 | 1k | ARIN | US | 3rd Dec 1993 |
| 199.79.240.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.241.0/24 | 256 | ARIN | US | 6th Oct 2025 |
| 199.79.242.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.243.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.244.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.246.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.248.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.249.0/24 | 256 | ARIN | US | 10th Feb 1994 |
| 199.79.252.0/23 | 512 | ARIN | US | 10th Feb 1994 |
| 199.80.0.0/21 | 2k | ARIN | US | 9th Dec 1993 |
| 199.80.16.0/21 | 2k | ARIN | US | 6th Dec 1993 |
| 199.80.24.0/22 | 1k | ARIN | US | 6th Dec 1993 |
| 199.80.32.0/20 | 4.1k | ARIN | US | 16th Mar 1994 |
| 199.80.48.0/22 | 1k | ARIN | US | 16th Mar 1994 |
| 199.83.0.0/21 | 2k | ARIN | US | 18th Dec 1993 |
| 199.83.102.0/24 | 256 | ARIN | US | 5th Feb 2020 |
| 199.83.12.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.83.136.0/22 | 1k | ARIN |  CA | 18th Jan 2011 |