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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
27,021 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.153.176.0/21 | 2k | ARIN |  US | 11th Aug 1993 |
| 198.153.190.0/23 | 512 | ARIN | US | 11th Aug 1993 |
| 198.153.196.0/24 | 256 | ARIN | US | 11th Aug 1993 |
| 198.153.197.0/24 | 256 | ARIN | US | 12th Aug 1993 |
| 198.153.198.0/24 | 256 | ARIN | US | 12th Aug 1993 |
| 198.153.199.0/24 | 256 | ARIN | US | 12th Aug 1993 |
| 198.153.200.0/24 | 256 | ARIN | US | 13th Aug 1993 |
| 198.153.202.0/24 | 256 | ARIN | US | 13th Aug 1993 |
| 198.153.203.0/24 | 256 | ARIN | US | 13th Aug 1993 |
| 198.153.204.0/24 | 256 | ARIN | US | 13th Aug 1993 |
| 198.153.205.0/24 | 256 | ARIN | US | 17th Aug 1993 |
| 198.153.206.0/24 | 256 | ARIN | US | 17th Aug 1993 |
| 198.153.207.0/24 | 256 | ARIN | US | 22nd Oct 2013 |
| 198.153.208.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.153.209.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.153.210.0/24 | 256 | ARIN | US | 8th Jul 2026 |
| 198.153.211.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.153.214.0/24 | 256 | ARIN | US | 4th Aug 2026 |
| 198.153.218.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.153.220.0/24 | 256 | ARIN | US | 17th Aug 1993 |
| 198.153.221.0/24 | 256 | ARIN | US | 17th Aug 1993 |
| 198.153.222.0/24 | 256 | ARIN | US | 18th Aug 1993 |
| 198.153.232.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.233.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.234.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.235.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.236.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.237.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.246.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.247.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.248.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.249.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.250.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.251.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.252.0/24 | 256 | ARIN | US | 20th Aug 1993 |
| 198.153.254.0/24 | 256 | ARIN | US | 30th Aug 1993 |
| 198.153.32.0/20 | 4.1k | ARIN | US | 3rd May 1993 |
| 198.153.48.0/21 | 2k | ARIN | US | 3rd May 1993 |
| 198.153.56.0/23 | 512 | ARIN | US | 3rd May 1993 |
| 198.153.58.0/23 | 512 | ARIN | US | 1st Jul 2025 |
| 198.154.0.0/23 | 512 | ARIN | US | 3rd May 1993 |
| 198.156.0.0/16 | 65.5k | ARIN | US | 4th May 1993 |
| 198.157.0.0/16 | 65.5k | ARIN | US | 4th May 1993 |
| 198.158.0.0/16 | 65.5k | ARIN | US | 4th May 1993 |
| 198.16.0.0/22 | 1k | ARIN | US | 30th Nov 1992 |
| 198.16.8.0/21 | 2k | ARIN | US | 3rd Dec 1992 |
| 198.160.132.0/23 | 512 | ARIN | US | 20th Aug 1993 |
| 198.160.137.0/24 | 256 | ARIN | US | 23rd Aug 1993 |
| 198.160.138.0/24 | 256 | ARIN | US | 23rd Aug 1993 |
| 198.160.141.0/24 | 256 | ARIN | US | 24th Aug 1993 |