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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,244 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.133.186.0/24 | 256 | ARIN |  US | 27th Apr 1993 |
| 198.133.190.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.133.191.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.133.193.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.133.194.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.133.195.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.133.196.0/24 | 256 | ARIN | US | 27th Apr 1993 |
| 198.133.197.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.198.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.200.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.202.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.203.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.205.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.207.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.208.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.209.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.211.0/24 | 256 | ARIN | US | 28th Apr 1993 |
| 198.133.212.0/23 | 512 | ARIN | US | 28th Apr 1993 |
| 198.133.215.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.133.216.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.217.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.218.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.220.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.221.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.222.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.223.0/24 | 256 | ARIN | US | 29th Apr 1993 |
| 198.133.226.0/24 | 256 | RIPE NCC |  GB | 30th Apr 1993 |
| 198.133.231.0/24 | 256 | ARIN |  CA | 30th Apr 1993 |
| 198.133.232.0/24 | 256 | ARIN | US | 30th Apr 1993 |
| 198.133.233.0/24 | 256 | ARIN | US | 30th Apr 1993 |
| 198.133.234.0/24 | 256 | ARIN | US | 15th May 2025 |
| 198.133.235.0/24 | 256 | ARIN | US | 30th Apr 2025 |
| 198.133.236.0/24 | 256 | ARIN | US | 5th May 1993 |
| 198.133.239.0/24 | 256 | ARIN | US | 5th May 1993 |
| 198.133.240.0/24 | 256 | ARIN | US | 5th May 1993 |
| 198.133.242.0/24 | 256 | ARIN | US | 5th May 1993 |
| 198.133.243.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.133.247.0/24 | 256 | ARIN | US | 5th May 1993 |
| 198.133.248.0/24 | 256 | ARIN | US | 15th Jan 2014 |
| 198.133.249.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.133.250.0/23 | 512 | ARIN | US | 6th May 1993 |
| 198.133.252.0/23 | 512 | ARIN | US | 6th May 1993 |
| 198.133.254.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.133.64.0/21 | 2k | ARIN | CA | 31st Mar 1993 |
| 198.133.72.0/24 | 256 | ARIN | CA | 31st Mar 1993 |
| 198.133.73.0/24 | 256 | ARIN | US | 7th Apr 1993 |
| 198.133.74.0/24 | 256 | ARIN | US | 7th Apr 1993 |
| 198.133.76.0/24 | 256 | ARIN | US | 8th Apr 1993 |
| 198.133.78.0/24 | 256 | ARIN | US | 8th Apr 1993 |
| 198.133.80.0/22 | 1k | RIPE NCC | GB | 9th Apr 1993 |