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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,248 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.187.128.0/24 | 256 | ARIN |  US | 23rd Sept 1993 |
| 198.187.134.0/24 | 256 | ARIN | US | 9th Sept 1994 |
| 198.187.136.0/24 | 256 | ARIN | US | 23rd Sept 1993 |
| 198.187.140.0/24 | 256 | ARIN | US | 24th Jan 2013 |
| 198.187.141.0/24 | 256 | ARIN | US | 23rd Sept 1993 |
| 198.187.142.0/24 | 256 | ARIN | US | 23rd Sept 1993 |
| 198.187.143.0/24 | 256 | ARIN | US | 23rd Sept 1993 |
| 198.187.144.0/24 | 256 | ARIN | US | 23rd Sept 1993 |
| 198.187.145.0/24 | 256 | ARIN | US | 23rd Sept 1993 |
| 198.187.146.0/24 | 256 | ARIN | US | 24th Sept 1993 |
| 198.187.150.0/24 | 256 | ARIN | US | 24th Sept 1993 |
| 198.187.151.0/24 | 256 | ARIN | US | 24th Sept 1993 |
| 198.187.152.0/24 | 256 | ARIN | US | 24th Sept 1993 |
| 198.187.153.0/24 | 256 | ARIN | US | 24th Sept 1993 |
| 198.187.155.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.156.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.157.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.158.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.159.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.16.0/21 | 2k | ARIN | US | 22nd Jun 1993 |
| 198.187.162.0/23 | 512 | ARIN | US | 27th Sept 1993 |
| 198.187.164.0/23 | 512 | ARIN | US | 27th Sept 1993 |
| 198.187.166.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.167.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.168.0/23 | 512 | ARIN | US | 3rd Apr 2025 |
| 198.187.170.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.171.0/24 | 256 | ARIN |  BM | 27th Sept 1993 |
| 198.187.176.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.177.0/24 | 256 | ARIN | US | 27th Sept 1993 |
| 198.187.178.0/23 | 512 | ARIN | US | 28th Sept 1993 |
| 198.187.180.0/22 | 1k | ARIN | US | 28th Sept 1993 |
| 198.187.184.0/22 | 1k | ARIN | US | 28th Sept 1993 |
| 198.187.189.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.192.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.193.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.197.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.198.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.199.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.201.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.202.0/24 | 256 | ARIN | US | 28th Sept 1993 |
| 198.187.204.0/24 | 256 | ARIN | US | 29th Sept 1993 |
| 198.187.205.0/24 | 256 | ARIN | US | 29th Sept 1993 |
| 198.187.207.0/24 | 256 | ARIN | US | 29th Sept 1993 |
| 198.187.208.0/23 | 512 | ARIN | US | 29th Sept 1993 |
| 198.187.210.0/24 | 256 | ARIN | US | 29th Sept 1993 |
| 198.187.217.0/24 | 256 | ARIN | US | 30th Sept 1993 |
| 198.187.218.0/24 | 256 | ARIN | US | 30th Sept 1993 |
| 198.187.219.0/24 | 256 | ARIN | US | 30th Sept 1993 |
| 198.187.220.0/24 | 256 | ARIN | US | 30th Sept 1993 |
| 198.187.221.0/24 | 256 | ARIN | US | 30th Sept 1993 |