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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with the most unannounced blocks, largest first.
Unannounced blocks in United States
27,034 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.246.8.0/23 | 512 | ARIN |  US | 14th May 1994 |
| 199.246.80.0/21 | 2k | ARIN | US | 15th Mar 1996 |
| 199.247.88.0/21 | 2k | ARIN | US | 4th Jan 2018 |
| 199.247.96.0/19 | 8.2k | ARIN | US | 24th Jan 2018 |
| 199.248.128.0/22 | 1k | ARIN | US | 13th Sept 1994 |
| 199.248.132.0/23 | 512 | ARIN | US | 13th Sept 1994 |
| 199.248.134.0/23 | 512 | ARIN | US | 13th Sept 1994 |
| 199.248.138.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.139.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.140.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.141.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.142.0/23 | 512 | ARIN | US | 14th Sept 1994 |
| 199.248.146.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.147.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.148.0/22 | 1k | ARIN | US | 14th Sept 1994 |
| 199.248.152.0/23 | 512 | ARIN | US | 14th Sept 1994 |
| 199.248.154.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.155.0/24 | 256 | ARIN | US | 14th Sept 1994 |
| 199.248.157.0/24 | 256 | ARIN | US | 15th Sept 1994 |
| 199.248.158.0/24 | 256 | ARIN | US | 15th Sept 1994 |
| 199.248.159.0/24 | 256 | ARIN | US | 15th Sept 1994 |
| 199.248.16.0/21 | 2k | ARIN | US | 3rd May 1994 |
| 199.248.160.0/23 | 512 | ARIN | US | 15th Sept 1994 |
| 199.248.162.0/24 | 256 | ARIN | US | 15th Sept 1994 |
| 199.248.163.0/24 | 256 | ARIN | US | 15th Sept 1994 |
| 199.248.169.0/24 | 256 | ARIN | US | 16th Sept 1994 |
| 199.248.170.0/24 | 256 | ARIN | US | 16th Sept 1994 |
| 199.248.171.0/24 | 256 | ARIN | US | 16th Sept 1994 |
| 199.248.172.0/24 | 256 | ARIN | US | 16th Sept 1994 |
| 199.248.179.0/24 | 256 | ARIN | US | 19th Sept 1994 |
| 199.248.180.0/24 | 256 | ARIN | US | 19th Sept 1994 |
| 199.248.181.0/24 | 256 | ARIN | US | 19th Sept 1994 |
| 199.248.182.0/24 | 256 | ARIN | US | 20th Sept 1994 |
| 199.248.184.0/24 | 256 | ARIN | US | 20th Sept 1994 |
| 199.248.187.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 199.248.188.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 199.248.190.0/24 | 256 | ARIN | US | 21st Sept 1994 |
| 199.248.191.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 199.248.192.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 199.248.193.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 199.248.194.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 199.248.195.0/24 | 256 | ARIN | US | 22nd Sept 1994 |
| 199.248.196.0/24 | 256 | ARIN | US | 23rd Sept 1994 |
| 199.248.199.0/24 | 256 | ARIN | US | 16th Mar 2012 |
| 199.248.202.0/24 | 256 | ARIN | US | 23rd Sept 1994 |
| 199.248.203.0/24 | 256 | ARIN | US | 23rd Sept 1994 |
| 199.248.204.0/24 | 256 | ARIN | US | 23rd Sept 1994 |
| 199.248.206.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 199.248.207.0/24 | 256 | ARIN | US | 27th Sept 1994 |
| 199.248.210.0/24 | 256 | ARIN | US | 28th Sept 1994 |