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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,315 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.193.0.0/16 | 65.5k | ARIN |  US | 17th Jun 1993 |
| 198.194.0.0/16 | 65.5k | ARIN | US | 17th Jun 1993 |
| 198.196.0.0/16 | 65.5k | ARIN | US | 17th Jun 1993 |
| 198.197.0.0/16 | 65.5k | ARIN | US | 17th Jun 1993 |
| 198.198.0.0/16 | 65.5k | ARIN | US | 17th Jun 1993 |
| 198.199.0.0/22 | 1k | ARIN | US | 18th Jun 1993 |
| 198.199.128.0/24 | 256 | ARIN | US | 25th Feb 1994 |
| 198.199.129.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 198.199.130.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 198.199.131.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 198.199.132.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 198.199.133.0/24 | 256 | ARIN | US | 1st Mar 1994 |
| 198.199.135.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.137.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.138.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.139.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.141.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.142.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.143.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.144.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.146.0/23 | 512 | ARIN | US | 3rd Mar 1994 |
| 198.199.148.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.150.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.154.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.158.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.159.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 198.199.160.0/24 | 256 | ARIN | US | 4th Mar 1994 |
| 198.199.161.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.162.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.163.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.164.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.166.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.167.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.168.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.169.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.170.0/24 | 256 | ARIN | US | 7th Mar 1994 |
| 198.199.173.0/24 | 256 | ARIN | US | 10th Mar 1994 |
| 198.199.174.0/24 | 256 | ARIN | US | 13th Mar 1996 |
| 198.199.178.0/24 | 256 | ARIN | US | 9th Mar 1994 |
| 198.199.182.0/24 | 256 | ARIN | US | 9th Mar 1994 |
| 198.199.183.0/24 | 256 | ARIN | US | 9th Mar 1994 |
| 198.199.184.0/24 | 256 | ARIN | US | 16th Mar 1994 |
| 198.199.193.0/24 | 256 | ARIN | US | 14th Mar 1994 |
| 198.199.196.0/24 | 256 | ARIN | US | 14th Mar 1994 |
| 198.199.197.0/24 | 256 | ARIN | US | 14th Mar 1994 |
| 198.199.201.0/24 | 256 | ARIN | US | 14th Mar 1994 |
| 198.199.202.0/24 | 256 | ARIN | US | 14th Mar 1994 |
| 198.199.205.0/24 | 256 | ARIN | US | 17th Mar 1994 |
| 198.199.207.0/24 | 256 | ARIN | US | 14th Oct 1993 |
| 198.199.212.0/24 | 256 | ARIN | US | 27th Jul 2026 |