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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 198.137.132.0/24 | 256 | ARIN |  US | 6th May 1993 |
| 198.137.133.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.134.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.140.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.141.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.143.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.144.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.147.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.137.154.0/24 | 256 | ARIN | US | 10th Jun 2013 |
| 198.137.155.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.137.156.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.137.157.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.137.158.0/24 | 256 | ARIN | US | 7th May 1993 |
| 198.137.159.0/24 | 256 | ARIN | US | 5th Apr 1995 |
| 198.137.160.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.137.162.0/23 | 512 | ARIN | US | 10th May 1993 |
| 198.137.164.0/23 | 512 | ARIN | US | 10th May 1993 |
| 198.137.166.0/24 | 256 | ARIN | US | 10th May 1993 |
| 198.137.168.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.137.169.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.137.170.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.137.171.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.137.172.0/24 | 256 | ARIN | US | 11th May 1993 |
| 198.137.173.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.137.174.0/24 | 256 | ARIN | US | 14th Sept 2022 |
| 198.137.175.0/24 | 256 | ARIN | US | 12th May 1993 |
| 198.137.176.0/22 | 1k | ARIN | US | 12th May 1993 |
| 198.137.180.0/24 | 256 | ARIN | US | 13th May 1993 |
| 198.137.181.0/24 | 256 | ARIN | US | 13th May 1993 |
| 198.137.182.0/23 | 512 | ARIN | US | 13th May 1993 |
| 198.137.184.0/23 | 512 | ARIN | US | 18th Apr 2013 |
| 198.137.186.0/24 | 256 | ARIN | US | 13th May 1993 |
| 198.137.187.0/24 | 256 | ARIN | US | 13th May 1993 |
| 198.137.188.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.192.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.193.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.195.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.196.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.197.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.198.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.200.0/24 | 256 | ARIN | US | 17th May 1993 |
| 198.137.204.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.206.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.207.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.208.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.209.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.210.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.211.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.212.0/24 | 256 | ARIN | US | 19th May 1993 |
| 198.137.213.0/24 | 256 | ARIN | US | 19th May 1993 |